Grassland Society of Southern Africa

Abstract: Over the past few years, agribusiness, investment funds and government agencies have been acquiring long-term rights over large areas of land in Africa. Together with applicable national and international law, contracts define the terms of an investment project, and the way risks, costs and benefits are distributed. Who has the authority to sign the contract and through what process greatly influences the extent to which people can have their voices heard. Yet very little is known about the exact terms of the land deals. Drawing on the legal analysis of twelve land deals from different parts of Africa, this report discusses the contractual issues for which public scrutiny is most needed, and aims to promote informed public debate about them.

Abstract: Environmental Law provides a comprehensive and succinct examination of the entire environmental law landscape in South Africa. The second edition includes a new chapter on climate change, and also examines the following recent developments: the new environmental impact assessment (EIA) regime (2010 regulations) several amendments to the National Environmental Management Act and other environmental legislation the new National Environmental Management: Waste Act the new National Environmental Management: Integrated Coastal Management Act several important developments in delegated legislation numerous new cases, including the far-reaching Fuel Retailers decision in the Constitutional Court. Contents include: Introduction The Constitution and framework environmental legislation International environmental law Water law and the environment Conservation of biodiversity Pollution control and waste management Land use and planning Implementation and administration of environmental law Environmental justice: A South African perspective South Africa's position on climate change An accompanying CD containing important environmental legislation and leading cases. --------------------------------------------------------------------------------

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Abstract: The Chinese flora,with an estimated 30,000species,is of immense scientific and hortcultural importance.Noteworthy,too,is the traditional medicine of the country,which is based on the remarkable plant resources.Descriptions and identification keys for this diverse flora,until now unavilable in English,have been published over the past twelve years in the Flora of China,in conjunction with a separate illustrations series.Twenty-three of the total of 50 volumes have already been published,thanks to an unprecedented and long-standing collaboration between Western and Chinese scientists. Volume 22 of the illustrations series is devoted to one plant family of enormous significance, namely , the grasses (Poaceae or Gramineae). The poaceae range from the bamboos within the tribe Bambuseae to the widelycultivated rice, wheat , barley, and maize or corn, as well as many grasses used for animal forage, all plants of unparalleled importance to human life. A large proportion of the species of grasses depicted here, including many woody bamboos, occur naturally only in China.

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Abstract: This handbook, updated edition of the 2002 edition, seeks to address planning, monitoring, and evaluation in the context of the United Nations Development Programme (UNDP) and its evaluation policy. These documents provide the prescriptive content on what needs to be done, by whom, and by when. This handbook complements this content by providing UNDP programme units with guidance on 'how to' and practical tools to strengthen results-oriented planning, monitoring, and evaluation in UNDP. The guiding framework of UNDP for planning, monitoring, and evaluation is provided in the �Programme and Operations Policy and Procedure� (POPP), the evaluation policy , and the United Nations Evaluation Group (UNEG) 'Standards for Evaluation in the UN System'. The contents include the following: 1. Planning, monitoring, and evaluation for development results 2. Planning for results: Practical applications 3. Planning for monitoring and evaluation 4. Monitoring for results 5. Evaluating for results 6. Initiating and managing an evaluation 7. Assuring the quality of evaluation design and methodology 8. Enhancing the use of knowledge from monitoring and evaluation

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Abstract: Widely distributed in Asia, Africa and Latin America, bamboo and rattan are the most important non-timber forest products among the world�s plant and forest resources. Theses versatile plants have a great potential in poverty reduction, industry development and sustainable development in rural areas. This book introduces the achievements and development trends with regard to bamboo and rattan research in China and other countries. Both scientifically instructive and practically useful, the book covers a wide range of research and development fields and will be of great help as a guide in practice to sustainable development of bamboo and rattan in the world.

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Abstract: Chapter 1 Analysis of Environmental Background Chapter 2 Potential Productivity of Mountain Grassland Resources Chapter 3 Study on Biomes of Mountain Grassland Ecosystem Chapter 4 Nutrient Cycle in Grassland Ecosystem Chapter 5 Ecological Function of Mountain Grassland Ecosystem Chapter 6 Position and Role of Grassland Ecosystem in Mountainous Economical Agroecosystem Reference

Abstract: Published studies relating erosion and productivity have been generally based on information derived from expert opinion on the extent and severity of soil erosion and on limited data on its impact on soil productivity, resulting in widely varying yield and economic loss estimates. In contrast, this report estimates the impact of soil erosion on productivity by collating, synthesizing and comparing the results from published site-specific soil erosion-productivity experiments at a global scale. Using crop yield as a proxy measure for soil productivity, this analysis uses the data from 179 plot-level studies from 37 countries identified in the soil science literature to calculate absolute and relative yield losses per Mg or cm of soil erosion for various crops, aggregated by continent and soil order. The results show that effects of past erosion on yields differ greatly by crop, continent and soil order. However, aggregated across soils on the continental level, absolute differences in productivity declines Mg-1 of soil erosion are fairly small. However, depending on the specific crop and soil, relative erosion-induced yield losses Mg-1 or cm-1 of soil erosion were two to six times smaller in North America and Europe than in Africa, Asia, Australia and Latin America. The higher losses in the latter continents are due primarily to much lower average yields, so that with identical amounts of erosion, yields decline more rapidly in relative terms. Studies using management practices as their experimental method to determine effects of present erosion showed much greater absolute and relative yield losses, which may be an artefact of the combined effect of erosion and variable management practices. Comparing the results of past and present erosion studies indicates that inappropriate soil management may amplify the effect of erosion on productivity by one or several orders of magnitude. Good soil management for effective erosion control and maintaining productivity, therefore, is imperative to meet the needs of the world's present and future population.

Abstract: China is rich in bamboo resources which contain 400 odd species of 30 genera, and among the countries that have the most bamboo species and the largest yields in the world. For thousands of years, bamboo has glittered in Chinese culture, arts and daily life. It is an important component of Chinese traditional culture. Generations of Chinese bamboo processing masters, through persistent inventive exertion for numerous years, have developed a unique bamboo processing art. Chinese bamboo processing art combines the traditional philosophical essence with national life style, it takes root from the daily life, and expresses more distinctive existence than that in daily life, offering aesthetic enlightenment and imagination. The aim of this book is to show the charm and elegant demeanor of bamboo art, not only find its place in history, but also make this traditional art carried forward, innovated and developed.

Abstract: Main Contents 1. Preface 2. Vascular type 3. Abbreviation 4. Systematic Positions 5. Bamboo Culm Structure (1) Melocanna Trin (2) Schizostachyum (3) Pseudostachyum (4) Cephalostachyum (5) Thyrsostachys (6) Melocalamus (7) Dinochloa (8) Neomicrocalamus (9) Bambusa (10) Neosinocalamus (11) Dendrocalamopsis (12) Dendrocalamus (13) Gigantochloa (14) Indosasa (15) Sinobambusa (16) Brachystachyum (17) Phyllostachys (18) Hibanobambusa (19) Shibataea (20) Semiarundinaria (21) Chimonobambusa (22) Qiongzhuea (23) Chimonocalamus (24) Drepanostachyum (25) Ampelocalamus (26) Fargesia (27) Yushania (28) Acidosasa (29) Oligostachyum (30) Pleioblastus (31) Bashania (32) Gelidocalamus (33) Pseudosasa (34) Sasa (35) Indocalamus 6. Key to genera of Bambusoideae 7. Appendix Material 8. Index

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Abstract: Anji has excellent natural ecology, thousands hectare of bamboo forest. The forest cover rate reaches 69.3%. The National Bamboo Forest Park, the Headstream of Huangpujiang River-Longwangshan natural protection area has fantastic scenery and perfect protection of its aboriginality . More than 100 different natural or human culture sights spreads all over the county, which looks like bright pearls enchased in the mountains and river. There are too many beautiful things to see.

Abstract: 1. Floristic Part (1) Natural Environment (2) Distributive Types of Genera (3) Eco-Geographical Distribution of Species (4) Analysis of endemic Species (5) Compare with Adjacent Flora (6) Floristic Characteristics and Areal Area 2. Systematic Part (1) Index to the System (2) Gramineae (3) Key to The Genera (4) Subfam.1.Oryzoideae (5) Subfam.2.Arundinoideae (6) Subfam.3.Pooideae 3. References 4. Index Kunlun Mountains general situation

Abstract: This book is the happy result of a collaboration between scientists working in Australia and China. It combines taxonomic and descriptive skills with computer methodology, automated key making and databass applications. China has a rich grass flora � some 213 genera and 1124 species, according to the researches of one of authors, Mr. XU ZHU � so that this account of the grass genera of China, employing automated descriptions and keys, will be major contribution to the literature and a useful tool ofr both pure and applied plant scientists. It constitutes , in effect, part of a series of account of grass genera of different parts of the world in the preparation of which Drs Watson and Dallwitz have been engaged.

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Abstract: Gramineae is the most widely distributed family of flowering plants. It is of the greatest use to the human race in all plants of the earth. The leaves of all gasses are very similar in gross morphology. but they are very different and more beautiful surface view in microscopical structure of leaf epidermis. The character of leaf epidermis of grasses are not only the more important for identification of species in the leaf stage, but also very important to define the subfamily in systematics. This book contains two parts, the first part deals with general microscopical structure of leaf epidermis; the second part deals with Chinese descriptions of 6 subfamilies, 114 genera 285 species and 15 varieties, each species or variety is illustrated with 2 micro-photographs for the adaxial and abaxial surface, each micro photograph is accompanied with short English note. It will serve as a key reference book to botanists, agriculturists, horticulturists etc. and also as a pictorial source book for artists.

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Abstract: Main Contents 1. The ecological environment of rangeland 2. The classes of rangeland (1) Map of rangeland distribution in Qinghai province I. Wood land and coarse grasses type II. Shrub and coarse grasses type III. Dry pastureland type IV. Desert rangland type V. Meadow rangeland type 3. The main plant resource of rangeland (1) Appendix a. The index of plant Chinese name b. The index of plant Latin name (2) Acknowledgement

Abstract: As one of the major bamboo-growing countries in the world, China has long been known as s kingdom of bamboos. China is not only rich in species of bamboos but also in endemic genera and species. This altas contains 23 genera, 90 species, 8 varieties and 6 forms of bamboos in this county. All the photographs in this collection represent firsthand materials gathered by the authors during a long period of investigation and field observation. For example, the photograph of Chimonobambusa szechuanensis Rendle was taken in Washan of Sichuan Province,and the photograph of Dendrocalamus sinicus Chia& J.L.Sun was taken in Xishuangbanna Daizu Zizhizhou of Yunnan Province. Each species is illustrated with 2-3photographs for the purpose of showing the beautiful natural landscapes and the morphological characters, especially the young shoots. Altogether 273 colored photographs(including some of utilization)are contained in this atlas, which aims to give the readers a panorama of Chinese bamboos .Each photograph is accompanied with a short caption which summarizes all the available information about that bamboo. It will serve as a key reference book to botanists and horticulturists, and also as a pictorial source-book for artists, amateur photographers and bamboo lovers. In this sense, this book can be enjoyed by both scientists and ordinary readers.

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Abstract: Question: Can wild ungulates efficiently maintain and restore open habitats? Location: Brandenburg, NE Germany. Methods: The effect of wild ungulate grazing and browsing was studied in three successional stages: (1) Corynephorus canescens-dominated grassland; (2) ruderal tall forb vegetation dominated by Tanacetum vulgare; and (3) Pinus sylvestris-pioneer forest. The study was conducted over 3 yr. In each successional stage, six paired 4 m2-monitoring plots of permanently grazed versus ungrazed plots were arranged in three random blocks. Removal of grazing was introduced de novo for the study. In each plot, percentage cover of each plant and lichen species and total cover of woody plants was recorded. Results: Wild ungulates considerably affected successional pathways and species composition in open habitats but this influence became evident in alteration of abundances of only a few species. Grazing effects differed considerably between successional stages: species richness was higher in grazed versus ungrazed ruderal and pioneer forest plots, but not in the Corynephorus sites. Herbivory affected woody plant cover only in the Pioneer forest sites. Although the study period was too short to observe drastic changes in species richness and woody plant cover, notable changes in species composition were still detected in all successional stages. Conclusion: Wild ungulate browsing is a useful tool to inhibit encroachment of woody vegetation and to conserve a species-rich, open landscape.

Abstract: Four Trifolium repens (white clover) cultivars were evaluated under field conditions to determine the potential of these cultivars to sucessfully develop Rhizobium-associated root nodules. Nodulation of T. repens is often poor, because of suboptimal environmental conditions or absence of host-specific rhizobia. The cultivars Huia, Haifa, Ladino and Regal were selected, as these are popular cultivars available in South Africa. Thousand seed mass (TSM) of each cultivar was measured to determine viability of seed and the possible interaction between TSM and nodulation. Mean TSM values of the cultivars differed significantly, with Huia having the highest TSM followed by Haifa, Ladino and Regal. Biomass production was also measured as an indicator of nitrogen fixation efficiency. The cultivar Huia, with the highest TSM values, resulted in the highest biomass production. Nodulation indices were determined from the size, number and colour of the nodules. All plants, regardless of cultivar, formed nodules within 8 weeks. It was concluded that TSM had no effect on nodulation. Planting date with associated temperature effects and the intrinsic cultivar effect also had no influence on nodulation. It was therefore concluded that nodulation potential of the four cultivars tested was similar under environmental conditions that prevailed during the study.

Abstract: Arthropods are valuable biological indicators owing to strong relationships with primary producers. The supposition that arthropod�plant interactions are constant over seasons was tested using Mantel tests on correlations between these groups. A total of 78 plant species and 108 arthropod families were sampled monthly from the endangered Bloemfontein Dry Grassland at the Free State National Botanical Gardens between April 2009 and March 2010. Interaction strengths between plants and arthropods varied within a calendar year; being strongest in winter months (July and August), initiation of the growth season (November) and peak growth season (February and March). It was hypothesised that variation was caused by changing primary productivity. The trophic composition of the arthropod community supported this hypothesis as the ratio between primary consumers (herbivores) and secondary consumers (predators and parasitoids) showed patterns that coincided with periods of strong arthropod�plant interactions. Patterns were explained by multiple theories linking plant and arthropod diversity. It was concluded that arthropod assemblages are closely linked to primary producers, the abiotic environment and top-down trophic forces at different times of the year. Future arthropod-based studies should be performed with clear objectives and seasonal benchmark conditions to overcome these variations.

Abstract: Created in 1968 in Zimbabwe, the Gonarezhou National Park (GNP) is a protected area dedicated to the conservation of wildlife resources. This paper offers insights in wildlife management and issues related to climate change and the associated implications to wildlife management in the GNP.

Abstract: The relevance of land-use planning tools such as the Land Use and Allocation Plan (LUAP)is more than ever a necessity to face challenges of natural resources degradation (water, soil and forest) the effects of which worsen food insecurity and climate changes. This resources degradation is mainly caused by the indiscriminate search for agricultural lands due to extensive farming. Land-use planning enables managers and practitioners to define the use of the areas (agricultural, forest, pastoral, and biodiversity). Compliance with this planning requires an agricultural intensification and respect for biodiversity. This will enhance progress in effectively tackling both climate change and food security issues.

Abstract: Rainfall variability is a key constraint to agricultural production, livelihoods and economic growth in many developing countries. This is likely to be exacerbated in many places as rainfall variability increases (even where the total amount of rain increases) as a result of climate change. Changes in rainfall will also increase variability in groundwater recharge and river flow, thus affecting all water sources. Water storage, in its various forms, provides a mechanism for dealing with variability which, if planned and managed correctly, increases water security, agricultural productivity and adaptive capacity. As such, water storage can make an important contribution to safeguarding livelihoods and reducing rural poverty. However, ill-conceived water storage is a waste of financial resources and, rather than mitigate, may aggravate negative climate change impacts. Systems that combine complementary storage options are likely to be more adaptable and sustainable than those based on a single storage type. More systematic planning and management is required to avoid the mistakes of the past and to ensure more effective and suitable storage systems for the future.

Abstract: Article 1 of the United Nations Framework Convention on Climate change (UNFCCC, 1992) defined Climate system as the totality of the atmosphere, hydrosphere, biosphere, geosphere and their interaction with human being. The same article defined Climate Change as �a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to the natural variability observed over comparable time periods�. The Convention article also goes further to define �adverse-effect-of-climate-change� as �changes in the physical environment or biota resulting from climate change which have significant deleterious effects on the composition, resilience or productivity of natural and managed ecosystems or on the operation of socio-economic systems or on human health and welfare� (UNFCCC, 1992). Nigeria is particularly vulnerable to the impact of climate change in many fronts considering its geography, climate, vegetation, soils, economic structure, poor physical infrastructure, population and settlement, energy demands and agricultural activities (Okali, 2008). Nigeria is bounded in the south by over 850km long active coastline and in the north by a similar length of the Sahara Desert. The country is therefore permanently being ravaged by coastline erosion to the south as well as desertification to the north. Global warming is now acting as a catalyst to these two destructive natural forces (Agagu, 2009). The inter-annual variability of rainfall, particularly in the northern parts is large; often result in climate hazards, especially floods and droughts with their devastating effects on food production and associated calamities and sufferings. More often than not, certain parts of Nigeria receive less than 75 percent of their usual annual rainfall and this is particularly worrisome in the north (Adejuwon, 2004).

Abstract: Quantification of the short-term impact of burning in terms of the encroacher shrub Seriphium plumosum and grass tuft mortality, seed germination of the shrub (field and seed bank), aboveground phytomass production, plant density and basal cover of the grass sward was conducted in semiarid grassland following an accidental fire. These variables were determined along a terrain morphological unit where S. plumosum density increased with altitude. On average 57% of S. plumosum seedlings were killed by fire, but fire had no significant (P > 0.05) influence on the mortality of mature shrubs. Fire significantly (P . 0.01) stimulated seedling emergence of S. plumosum, to such an extent that an average of 510 seedlings ha-1 occurred on the foot slope, while only 9.14 seedlings ha-1 emerged in the unburnt treatment. Seedling emergence showed greater association with protection from direct sunlight and seedlings emerged not closer than 281 mm from the nearest leaves (canopy) of a mature S. plumosum shrub. The aboveground phytomass production of the unburnt grass sward was nearly double that of the burnt areas over the first season following the fire. Fire as a control measure should be carefully handled because it can lead to increased encroachment of S. plumosum.

Abstract: Interactions between mature grass plants and grass seedlings have been found to be both facilitative and competitive. To examine the effects of aboveground and belowground competition on seedling biomass and the effects of soil depth on competitive interactions, seedlings of three locally common grass species (Eragrostis racemosa, Themeda triandra and Panicum maximum) were planted into a natural grass sward on three different parts of the landscape varying in soil depth. Three aboveground treatments (full light competition, no light competition and clipping to simulate grazing), and two belowground treatments (full belowground competition and belowground competition excluded by a root tube), were used. On all soil depths the three grass species differed in mean mass, with E. racemosa having the least mass and T. triandra having the greatest mass. Simulated grazing by clipping the surrounding sward created niches for seedling establishment. This highlights the importance of maintaining stocking rates at a level that promotes seedling establishment.

Abstract: Invasive species in Africa have important impacts on food security and biodiversity conservation. African floodplains in arid areas are critical wildlife habitats in addition to crop production and dry season livestock grazing. The study aimed to understand the patterns of spread of the invader Prosopis juliflora in a typical African floodplain characterised by both multiple dispersers and habitats. Data was collected on faecal seed density, establishment and vegetation composition, and subjected to non-parametric tests and regression analysis. The results showed that both livestock and wildlife species played a critical role in dispersal of Prosopis juliflora, especially yellow baboons (Papio cynocephalus), bush pigs (Potamochoerus larvatus), donkeys and goats. Habitat preference of wildlife dispersers and livestock herding patterns influenced the spatial pattern of invader seed influx. Establishment of Prosopis juliflora was enhanced by ecological disturbance such as in rested crop fields and habitats outside conservation areas as compared to those inside. Establishment was also higher inside the floodplain than outside probably due to higher seasonal soil resources. Lastly, indigenous woody species diversity declined significantly as the density of Prosopis juliflora increased. We conclude that patterns of spread of Prosopis juliflora were related to ecological disturbances, type of disperser and flooplain effect.

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Abstract: This study investigated the seasonal and plant species patterns of short-term intake rate (STIR) by Nguni goats fed six common browse species in subhumid subtropical savannas. Six 2-year-old castrated Nguni goats weighing an average of 26 kg each were penned individually and maintained on a basal diet of ram, lamb and ewe pellets and grass hay. The STIR was influenced by season, with the highest mean STIR recorded during the dry season (mean ± SEM: 0.18 ± 0.012 g DM s-1) and least during the late wet season (0.15 ± 0.009 g DM s-1). Broadleaf species had higher STIR than fine-leaf species (0.18 ± 0.052 g DM s-1 vs 0.14 ± 0.055 g DM s-1). Species that produce new leaves on new long shoots were consumed at higher rates than those that produce new leaves on short shoots (0.19 ± 0.054 g DM s-1 vs 0.15 ± 0.056 g DM s-1). STIR showed no clear patterns in relation to leaf chemistry. These results can be used to improve estimates of intake rates from free-foraging animals using direct observation methods based on time spent at a feeding station depending on the plant species and the season in which it is consumed.

Abstract: We assessed past and present vegetation patterns in relation to land use on a municipal commonage in South Africa. We asked specifically whether the reassignment of the commonage for the use of historically disadvantaged town residents after 1994 has impacted negatively on the vegetation of the commonage. Analysis of land cover change using aerial photography time series revealed that the most significant human impacts on the Bathurst commonage occurred prior to 1942 due to heavy and uncontrolled communal land use. Vegetation change since then has been characterised by a recovery of thicket vegetation and an encroachment of woody species into grassland. Additional field sampling of the species composition and age class distributions of trees and shrubs in thicket and broken thicket vegetation showed these units to be of high veld condition status. Thornveld and old lands have both been encroached upon by woody species, particularly by Acacia karroo, and possessed the lowest veld condition scores. There is little evidence, however, that recent land-use activities have impacted negatively on commonage vegetation. We discuss these results in terms of the vegetation�s potential to provide for the diverse needs of commonage users, and the implications for commonage management and policy.

Abstract: Mean annual soil respiration correlates with net primary productivity and therefore provides an indication of ecosystem functioning. Soil respiration, however, varies considerably in space and time owing to the influence of factors such as soil nutrient content, temperature and water content. Comparing soil respiration across a fence-line separating rangelands in contrasting condition can potentially isolate effects of rangeland management from other abiotic variables. To explore this idea, soil respiration was measured from 260 different collars across a fence-line contrast in the Nama Karoo, near Beaufort West, over a period of four days in May 2005. Differences in soil respiration across the fence-line were only evident when the data were analysed in relation to soil temperature. The large data set enabled delineation of boundary lines relating soil respiration to temperature on the two farms. The boundary line analysis showed that constraint on soil respiration was between 0.2 and 0.4 μmol CO2 m-2 s-1 greater under high compared to moderate stocking density. It was concluded that measurement of soil respiration is likely to be useful for detecting changes in ecosystem function as a result of over-utilisation of Karoo rangeland.

Abstract: The Grassland biome is the most transformed biome in South Africa, with cultivation and other human impacts having the largest effect on pristine grasslands. Conversion of natural grassland to cropland agriculture destroys natural vegetation seed banks. When croplands on the South African Highveld are abandoned, secondary succession often leads to low diversity Hyparrhenia hirta dominated plant communities. To investigate the effect of reseeding on secondary succession and botanical diversity, various reseeding treatments of cropland restoration were established on a recently abandoned cropland at Suikerbosrand Nature Reserve. Plots combining two seed mixtures, two seeding rates and two sowing methods were monitored and evaluated. The sowing method (plough vs rip-line) had the largest influence on the suppression of relic weeds as well as possible establishment of local non-sown species. The rip-line plots, where more resources were available due to spaces between the rip-lines, initially experienced higher densities of relic weeds followed by an increase in local non-sown species densities. Hyparrhenia hirta was one of the non-sown perennials increasing in the rip-line plots. The growth of H. hirta and relic weeds was, however, controlled in the plough plots, where species densities and phytomass production of perennial sown-in species were the highest.

Abstract: Information at local scale on impacts of climate variability and climate change are crucial for planning of adaptation strategies and practices in agriculture. There is a diversity of approaches and methods available for understanding the impacts of climate change on agriculture. In general, climate change impact assessments primarily build on the data availability of crop production/yield records, observed climate data, climate change scenarios, hydrological, soil and socio-economic data. In addition, these assessments must be based on an understanding of what future climate will look like and how its variability will affect the biophysical and socio-economic systems associated with agriculture. This paper briefly presents the results of previous assessments for Africa and seeks to identify future priorities with respect to data, methods and tools for climate change impact assessment in agriculture.

Abstract: Lablab purpureus is a multipurpose legume with potential as a vegetable, pulse or forage crop for smallholder farming systems of southern Africa. Its use in the region is limited because the long-season forage types available result in unreliable seed set. In the first of three field evaluations conducted in Limpopo province, South Africa, 33 introduced accessions and three local varieties were evaluated. Days to 50% flowering and to maturity ranged from 51 to >150 days after planting (DAP) and from 90 to 197 DAP, respectively. Most accessions produced

Abstract: SA is 'Aware' Of Shale Gas Issues Thursday, 24 February 2011 | | 1 Comment Image by Dada Image by Dada Cape Town - The need for SA to explore for gas is also informed by its interest in reducing greenhouse gas emissions, Energy Minister Dipuo Peters said on Thursday. Responding to questions during a media briefing at Parliament about the outcry over shale gas exploration in the Karoo using the fracking method, Peters said that while SA knew it had potential for gas, "we're also alive to the environmental challenges that the process would generate". That was why the government would ensure that any development was subjected to environmental impact assessment. "And I believe that the shale gas exploration would allow us as South Africans to know whether we do have enough gas reserves to use them for power generation or for any other energy need that we have in South Africa." Peters said she would advise and request the environmental groups to understand that the need for SA to explore for gas was also informed by its interest to reduce greenhouse gas emissions. Jobs "Because if we don't use that gas for whatever purposes that we would want to use it for, it will be released into the atmosphere and it will also create another particular challenge." It was important to engage the environmental groups and appeal to them to understand that SA needed to develop and create the necessary jobs. "But, we are alive to the need for us to reduce our greenhouse gas emissions, but also to make sure that we adhere to the National Environmental Management Act (Nema)," Peters said. The Cape Times reported earlier this week that farmers, landowners and community members in the Karoo were bolstering their opposition to applications by energy companies Shell, Bundu and Falcon to explore for shale gas, a non-renewable form of energy, in 95 000km² in the Karoo. Shell was the largest applicant and had submitted three applications which extended over 90 000km². The exploration and mining method it intended using was a "highly invasive, water-intensive and potentially toxic process called fracking", the newspaper reported. A key collective initiative had been launched in Graaff-Reinet, where attorney Derek Light was spearheading the legal opposition against Shell, Bundu and Falcon on behalf of hundreds of Karoo farmers, landowners and community members. Public participation "The available information on fracking indicates that it is a highly invasive process with a high risk of contamination of the environment and, in particular to underground water and air, it necessitates the use of large volumes of water for the drilling process and substantial quantities of water in the fracking process. "It also involves the use of sand and highly toxic chemicals," Light was quoted. Shell and Golder Associates (the company appointed by Shell to conduct its public participation process and compile its Environmental Management Programme) had publicly stated that fracking posed no risk to the environment, the Cape Times reported. Date: 24 February 2011

Abstract: Journalist Heather Dugmore is up in arms about Shell�s bid to start hydraulic fracturing (�fracking�) over 30000 square kilometres in the Karoo in the hunt for natural gas reserves. Here�s her article �Will Shell Frack up the Karoo?� which ran widely in the press this week: Farmers, communities, environmental organisations, geologists and water specialists are up in arms about global energy and petrochemical company Shell�s application to explore for shale gas over 30 000 square kilometres in the water-stressed Karoo. The proposed exploration method, called hydraulic fracturing or �fracking� involves drilling boreholes 4-5 kilometres deep, followed by the introduction of a mixture of chemicals, sand and millions of litres of water into the boreholes under enormous pressure to fracture the geological structures and force the free-flow of shale gas, also called �natural gas�. This process determines whether viable amounts of shale gas exist for future exploitation based on the same method. �Fracking has been described as �planting chemical bombs underground� says Environmental Consultant and farmer, Fritz Bekker who is spearheading an opposition group of farmers and non-government organisations against another application by a company called Advasol (Pty) Limited to explore for gas from Struisbaai to Mossel Bay, extending 20 kilometres down the southern Cape coast. �With an approved exploration right, an applicant such as Shell may drill as many exploration boreholes as it can afford, which may be hundreds or even thousands depending on the area�s geology. Each borehole may be subjected to the fracking process,� continues Bekker. �It is important to note that the most significant adverse environmental impacts of earth gas exploration may already occur during the exploration phase. �Fracking has been condemned in many countries in the world and despite assurances from companies using this method that they will prevent any leakages, I need to warn farmers, landowners and communities in the Karoo that it poses a significant threat of chemical and gas contamination to the region�s scarce water sources. Both the surface and ground water is highly vulnerable to contamination once pressurized shale gas is liberated through the drilling and fracking process. �The long-term effects of toxic chemicals used in the fracking process are only now becoming apparent in countries where it has been used. The chemicals used during fracking in America have been positively linked to cancer, Parkinson�s, Alzheimer�s, diabetes, asthma, learning disorders and endocrine disrupting effects.� �If they drill they will also need large quantities of water and storage space for vast volumes of flammable, potentially toxic drilling mud in dams close to each drilling site.� Shell�s background document states that they are investigating a number of potential water sources to support the water-intensive fracking process, including �sea water, surface water and deep saline aquifers�. What they fail to say is that millions upon millions of litres of water are required for the process, which the Karoo does not have, and that as Bekker says: �It takes one litre of hydrocarbons such as shale gas to pollute one million litres of water. Shell has appointed Golder Associates (Golder) to compile the Environmental Management Plan and to undertake the public consultation process. Shell�s application to explore for shale gas has been submitted to the Petroleum Agency South Africa (PASA), which administers applications as a designated agent of the Minister of Energy. Golder�s background information document states: �PASA is expected to make a decision during 2011 whether to award the initial three year exploration rights.� Brent Baxter, Business Unit Leader, Environmental Services at Golder explains that �once a company lodges an application for an exploration right under the Mineral and Petroleum Resources Development Act they have 120 days to submit an Environmental Management Programme (EMP) in support of the exploration rights application. This is a legislated timeframe. Shell thus needs to submit an EMP, in support of each of the three exploration rights applications that they have lodged in the Karoo, by 18 April 2011.� To compile the research required for the EMP, the background document says: �a number of technical studies will be undertaken as part of the EMP process. Desktop studies will cover the larger application area and some fieldwork will be undertaken in selected areas to support the findings of the desktop studies.� The mention of �some fieldwork� is alarming. �The EMP by its nature must include specialist studies by geologists, ecologists, as well as specialist groundwater and surface water studies. Without these studies they cannot responsibly comment on the potential impact of gas exploration or mining required in the EMP,� Fritz Bekker explains. The applicant will not be able to budget for the management or mitigation of adverse environmental impacts that they have not identified properly during this phase of the application. Specialist environmental surveys such as botanical, hydrological and ground water investigations should be planned to take cognizance of seasonal variance, which is now not possible because of Shell�s haste to obtain approval. Baxter responds that �fieldwork to inform the EMP will be conducted by specialists between mid January and early February 2011 after which the draft EMP will be compiled. This fieldwork will of necessity be broad-based seeking to characterise the broad environment within which the proposed project takes place and seeking to verify information available in public datasets, such as national groundwater database information.� This means they are giving themselves two to three weeks of fieldwork to inform an EMP of this magnitude. Baxter says the period cannot be extended because of the 18 April deadline to submit to PASA. It begs the question whether an environmental management plan can ethically be presented without an indepth assessment of the potential impact on the environment. Baxter reassures that an Environmental Impact Assessment will be conducted �for any activities which are listed under the NEMA, before exploration activities commence�. One would expect so, but it still does not address the potential fracture in the EMP process. Asked why Golder and Shell did not rather apply for the period granted for the submission of the EMP to be extended, Baxter said this was not possible. The first of several meetings to be hosted by Shell and Golder is to take place in the Karoo town of Hofmeyr on Monday 24. Many farmers, communities and interested and affected organisations have not been informed about the meetings, nor about the application. Those who are aware of it are trying to spread the word as widely as possible, which is what Golder should be doing. However many interested and affected parties attend, it promises to be a heated exchange. Asked how they had advertised the meetings, Golder�s Public Participation Officer, Toni Pietersen, replied that they placed adverts in national and community newspapers. She said that it is unfortunate that they were placed approximately one week before the meetings were scheduled to begin; explaining that the Christmas period had hampered the timing. She adds that they had sent emails and posted the background documents to as many landowners, communities, farmers and affected organisations as they could locate. Their distribution process appears to be lacking since not even the President of Agri Eastern Cape, Ernest Pringle, who farms in the affected area, received contact or background information from them. Neither did the Chair of the Rooihoogte Farmer�s Association in the Middelburg district, Ed Kingwill, nor did the Regional Chief Director for the Department of Water Affairs in the Eastern Cape, nor the Nama Karoo Foundation, the conservation agency working to protect and preserve the natural and cultural heritage of the Karoo, based in Richmond and Graaff-Reinet in the Karoo. All received the information by chance via associates. �I have seen a documentary on frack mining and after I watched it I thought thank god I will never have to deal with this in the Karoo. So I thought until I received word about Shell�s application two days ago,� says the Nama Karoo Foundation�s Marina Beal. �Water, much of which is ancient water dating back millions of years, is the most precious commodity in the Karoo. This is a semi-desert area and it is a well-known fact how scarce water is in the Karoo, many parts of which are only now emerging from one of the worst droughts in decades. The potential for contamination of water through fracking is significant and potentially environmentally devastating.� Geohydrologist, Ahee Coetsee, who farms in the Middelburg district comments: �My initial reaction is that we all have to be extremely careful because despite assurances from mining companies that they follow ethical and green environmental procedures, we only need to look at the coal fields and acid mine drainage to know that while we might have excellent environmental laws, the enforcement of them and technical know-how is lacking. �We simply do not understand enough about the aquifer systems in the Karoo, which is why various studies are being done, such as by the Water Research Commission to look at the dolerite ring aquifer systems of the Karoo, from the surface to a depth of 3-500 metres. �There are many and varied aquifer systems in the Karoo, some dating back 300 million years and older. If Shell is planning to drill down to 4 kilometres and more, and if the boreholes constructed are not 100%, there can be cross contamination between aquifer systems. �If they do not comprehensively research and understand the hydro-geology of the exploration area, then they will need to be investigated from a technical and legal point of view.� Professor Bruce Rubidge, Director of the Bernard Price Institute for Palaentological Research at Wits University elaborates that when Shell talks about drilling down 4-5 kilometres in the Karoo, they are talking about accessing the Ecca group of rocks dated at approximately 270-million years: a time when the Karoo was an ancient marine environment. The Karoo is globally renowned for its fantastic wealth of fossil material, and Rubidge, who is a son of the Karoo, says �I care greatly for the Karoo and I would hate to see a big petroleum industry set up there. It would destroy the character of the Karoo.� Shell justifies the application in its background document by referring to shale gas as �the cleanest of the fossil fuels� and stating that: �South Africa is faced with the challenge of being able to meet future energy demands of an expanding economy. Developing a natural gas energy supply to help meet this growing demand would be of considerable value to South Africa.� What they fail to state is that the carbon footprint becomes outsize if they start calculating the process of extraction of shale gas through hydraulic fracturing, the process of accessing water from an as yet unidentified source, including possibly transporting in sea water, transporting the gas to market and the potential environmental degradation in this pristine part of the world. As Africa�s highest emitter of carbon, the government has committed to transform to a low carbon economy with a focus on renewable energy programmes, notably solar and wind. The Karoo is high on sun for solar power plants but extremely low on water.

Abstract: Smallholder farmers in developing countries face numerous limitations that hinder them from embracing improved agricultural practices and innovations with great potential for meaningful transformations of livelihoods. Consequently, farmers continue living in vicious cycles of poverty despite decades of government and donor expenditures on poverty alleviation. In the last two decades, research and development organizations collaborated in testing and validating selected fodder shrub species as reliable sources of less expensive and easily available protein feeds. With minimal interventions, the research findings have great potential to improve productivity for many smallholder farmers. Tested species include Calliandra calothyrsus, Leucaena spp., Chamaecytisus palmensis, Sesbania sesban, Morus alba and Gliricidia sepium. Dissemination and adoption surveys estimated that 205,000 smallholder farmers (40�50 per cent being women) had planted fodder shrubs by 2005. Currently, fodder shrubs contribute US$3.8 million annually to farmers� incomes and estimated potential annual income is US$81 million. Factors associated with success in fodder scaling-up include deliberate involvement of fodder technology champions, collective action in community mobilization and project implementation, pluralistic extension approaches, sustainable germplasm supply systems, broader partnerships and civil society campaigns. Constraints and challenges include: ineffective delivery of extension and research services, inhibitive policies, political interferences, frequent droughts and inadequate monitoring and evaluation systems.

Abstract: Tef, Eragrostis tef (Zucc.) Trotter, is the main Ethiopian cereal grown on 2.5 million ha annually, and serving as a staple food grain for more than 50 million people. The major constraints in tef husbandry are low productivity (average about 1 t ha21) and lodging. Scientific research on tef began in the late 1950s and over the years a number of improved varieties and management practices have been developed. However, the research outputs have, until recently, been little adopted by farmers. This paper gives an overview of new and impactful technological, institutional and partnership innovation undertaken by Debre Zeit Agricultural Research Centre with a new tef variety called Quncho. Quncho was developed from an intra-specific hybridization between two improved pure line selection varieties (DZ-01-974 and DZ-01-196). The variety DZ-01-974 is high yielding, but because of the seed colour (pale white) its preference by farmers was limited. On the other hand, the variety DZ-01-196 has been popular for its very white seed colour, but its productivity has been relatively low (1.6�1.8t ha21). Hence, a targeted cross to bring together the high- yielding traits of DZ-01-974 with the seed quality of DZ-01-196 was made in 2000. Quncho was then developed as an F2-derived recombinant inbred line (RIL) through a singleseed descent breeding method. Officially released in 2006, the Quncho variety is presently attracting farmers and seed growers.

Abstract: Tef [Eragrostis tef (Zucc.) Trotter] occupies two million hectares of land each year, which accounts for 28% of the total acreage. However, its productivity is constrained by drought. Development of drought resistant variety through inter-specific conventional crossing is crucial. Twenty five recombinant inbred lines (RILs) of E. tef var Kay Murii and Eragrostis pilosa were evaluated against the standard check and two parental lines to assess drought resistance trait variability under low moisture-stressed and non-stressed conditions using randomized complete block design of three replications. The experiment was conducted under rainout shelter at Debre Zeit, Ethiopia. Significant (p<0.05) differences were observed among genotypes for days-to-panicle-emergence, days-to-mature, tiller number, root length, root number, root biomass, shoot biomass and grain yield. All traits had shown high level of phenotypic and genotypic coefficients of variation, high estimates of heritability and genetic advance. Most RILs were early maturing and resist the moisture stress effect (<20% yield reduction), while key murii and few other RILs were strongly affected. Under stressed condition, RIL-16 and RIL-290 were superior in grain yield to all genotypes and most RILs had shown high value of water use efficiency. Based on drought susceptible index, 17 drought resistant RILs were identified. The result demonstrated wide variability among RILs for drought resistance traits and the potential of E. pilosa to widen tef gene pool.

Abstract: Thursday, 19 August 2010 | AFP Copenhagen - A Danish biotechnology company on Tuesday launched a new enzyme which it said will make it possible to turn agricultural waste into biofuel at a competitive price. The breakthrough will allow the biofuel industry to produce cellulosic ethanol for less than $2 per gallon (3.79 litres), Novozymes said in a statement. This cost would put the fuel on a par with petrol and conventional ethanol, the company said. Novozymes said the new enzyme, known as Cellic CTec2, breaks down cellulose in agricultural waste into sugars that can be fermented into ethanol, and could convert corn cobs and stalks, wheat straw and wood chips into fuel. "We have been working on this for the past 10 years and promised our customers and the market to be ready by 2010," Novozymes' chief executive Steen Riisgaard said in a statement. Riisgaard said he expected cellulosic ethanol to become even cheaper over time. "Our partners expect production costs to fall below $2 per gallon once their first commercial-scale plants are fully operational, and the cost will continue to drop in the future," he said in the statement. Tuesday's announcement prompted Novozymes' share price to rise 4.8% on the Danish stock market, to stand at $104. Novozymes said the new enzyme was developed with the help of $29.3m from the US Department of Energy. Large-scale commercial production of cellulosic ethanol is scheduled to start in 2011, and the company said the industry could create 1.2 million jobs in the US alone by 2022.

Abstract: Over the past half-century, agricultural production gains have provided a platform for rural and urban economic growth worldwide. In African countries, however, agriculture has been widely assumed to have performed badly. Foresight commissioned analyses of 40 projects and programmes in 20 countries where sustainable intensification has been developed during the 1990s-2000s. The cases included crop improvements, agroforestry and soil conservation, conservation agriculture, integrated pest management, horticulture, livestock and fodder crops, aquaculture and novel policies and partnerships. By early 2010, these projects had documented benefits for 10.39 million farmers and their families and improvements on approximately 12.75 million ha. Food outputs by sustainable intensification have been multiplicative - by which yields per hectare have increased by combining the use of new and improved varieties and new agronomic-agroecological management (crop yields rose on average by 2.13-fold), and additive - by which diversification has resulted in the emergence of a range of new crops, livestock or fish that added to the existing staples or vegetables already being cultivated. The challenge is now to spread effective processes and lessons to many more millions of generally small farmers and pastoralists across the whole continent. These projects had seven common lessons for scaling up and spreading: (i) science and farmer inputs into technologies and practices that combine crops-animals with agroecological and agronomic management; (ii) creation of novel social infrastructure that builds trust among individuals and agencies; (iii) improvement of farmer knowledge and capacity through the use of farmer field schools and modern information and communication technologies; (iv) engagement with the private sector for supply of goods and services; (v) a focus on women's educational, microfinance and agricultural technology needs; (vi) ensuring the availability of microfinance and rural banking; and (vii) ensuring public sector support for agriculture. This research forms part of the UK Government's Foresight Global Food and Farming project.

Abstract: This study reports on a simulation growth model developed to predict daily gain (DG) of dairy cattle heifers. The model input parameters are gross energy (GE), ash, crude protein (CP), organic matter digestibility (OMD), dry matter (DM), protein degradation variables and heifer initial body weight. Results from the simulation model show that at low levels of CP in elephant grass (Pennisetum purpureum) there is improved DG when supplemented with desmodium (Desmodium spp.) or lablab (Lablab purpureus) but as the CP in elephant grass increases there is reduced benefit from supplementation and at CP 100 g/kgDM there is no improvement in DG due supplementation. Supplementation with either lablab or desmodium at same percentage of diet had similar effect on DG. It is concluded that these two forage legumes could improve heifer growth, consequently reducing the time from weaning to mating weight of heifers in smallholder dairying where the CP content of elephant grass is low.

Abstract: This study examined yield trends and changes in soil chemical properties during a 26-year field experiment, involving a winter wheat�summer maize rotation on a loessial soil in China. Mean yields of wheat and maize increased significantly with increasing rates of manure (M) or inorganic nitrogen and phosphorus (NP) application. However, over time, the yield of both crops declined under the NP treatments, although the change was only significant for wheat. Positive yield responses for both crops were recorded under M+NP treatments. Soil organic matter and soil total N increased under all treatments. The Olsen P level dropped significantly in NP plots and increased markedly in manured plots. There was a reduction in soil exchangeable potassium under nearly all treatments, particularly on NP, where it dropped from an initial concentration of 245 mg kg-1 to ca. 110 mg kg-1. We conclude that annual inputs of NP fertilizers at rates of less than 240 kg ha-1 N and 52 kg ha-1 P were not sufficient to sustain crop production in the system investigated. The practice of applying organic manure as well as NP should be modified to facilitate continued crop production and to provide environmental protection.

Abstract: Over the past two decades, the issue of rural women in developing countries has evolved from relative obscurity to a primary concern among the growing community of researchers and policy makers who are interested in women's economic and social situation status. In respect to developing countries, rural women play a vital role in agriculture, daily reproductive tasks and income generating activities, etc. However, it is the reality that less value is given to their contributions, and rural women are less likely to realize their status to make a life better for themselves, families and communities. In this regard, participation of rural women in productive cooperation is an appropriate means for empowering them and reduction their poverty. This study was undertaken to review individual-economic factors affecting rural WP in "Paveh ball-making project" as a productive cooperative (co-op) in Iran. As an exploratory and descriptive-survey study, 120 rural women were selected from the cooperative in Paveh district using systematic probability method. The project was the first of its kind in the region. The study area is located in the west of Kermanshah province, in the mid-west of Iran. Necessary data and information were gathered using several methods such as documentary review, observation, PRA techniques, and a designed questionnaire. The result of path analysis showed that the socio�economic variables could explain about 61% of dependent variable (women participation). Trust to co-op staff, awareness, number of family, economical motivation, economic improvement of women�s family, years of membership, years of management at the cooperative, land and livestock ownership, were among the highly prevalent socio �economic factors that potentially have affected the participation of women in this co-op. As the factors influencing the participation of women are multiple and complex, a holistic approach should be adopted with emphasis on improving access to education, enhancing social status, increasing external funds and supports especially for rural women, encouraging ownership of local projects, and mechanisms to enhancing participation.

Abstract: Agricultural policy formulation in Sub Saharan Africa has been dominated by research initiatives that alienated other farmers and stakeholders. The Sub Saharan Africa Challenge Programme (SSA CP) seeks to use multi-stakeholder partnerships as an institutional innovation for agricultural policy formulation and development. This paper uses some experiences from the SSA CP to discuss the design principles for an effective partnership that can deliver relevant agricultural policies. It argues that consultation, negotiation, having a shared understanding of key relationships and interdependence between partners are important principles in multi stakeholder partners. Government�s role should be streamlined to be a participant, provider of a conducive environment for policy formulation and provider of public goods.

Abstract: Psidium guajava (guava) is recognised as the third most important inva­sive alien plant species in the moist savanna biome of South Africa, Lesotho and Swaziland. The cost of initial clearing of alien plants reaches up to R3 000-00 per ha, therefore the application of correct control methods is essential for cost-effective reduction of the spread. The aim of this study was to test the cost effectiveness of applying various herbicides to guava in the Swaziland Sour Bushveld. Four plots were selected for standing plant treatments, five for cut stump treatments and two for controls. Within each of these plots, five sub-plots were randomly located and the number of plant stems, base diameter, maximum height, and crown diameter was recorded before application of the herbicides. Picloram, fluroxypyr, bromacil, tebuthiuron and imazapyr were used either alone or in combinations. Eleven months after herbicide application, the treated plants were measured again. Bromacil/tebuthiuron liquid soil application gave the best results in terms of cost (0.09 c/stem) for standing plant treatments. The picloram/fluroxypyr cut stump treatment (4.5% concentration) cost the least to apply (0.05 c/stem), and no resprouting was observed. Results from this study can be used as baseline figures for managers planning to control guava.

Abstract: Understanding the relationships between biodiversity and land-use is a key element for the development of effective conservation strategies. We studied a mid-altitude steppe-like area of Southern France, the Causse de Sauveterre, that has been grazed for many centuries. The decrease of human population during the 20th century, particularly since the end of 2nd World War, and the ongoing changes in agricultural practices may have dramatic effects on many biodiversity components of these landscapes. Our study assesses landscape change and modifications in bird community composition through the repeated sampling of a network of sites after an interval of 15-19 years. We paid particular attention to the possible consequences of recent changes in agricultural policy on these communities. Landscape changes were studied through remote sensing, and bird community and vegetation changes by field sampling on 183 sites. Correspondence Analysis showed an overall trend towards landscape closure. This results in a decrease of open-habitat species that are fairly rare in Europe (e.g. Tawny Pipit Anthus campestris, Linnet Carduelis cannabina, Ortolan Bunting Emberiza hortulana), and in an increase of common forest species (e.g. the Common Chiffchaff Phylloscopus collybita and Winter Wren Troglodytes troglodytes). Although most of the avifauna changes seem to be explained by local landscape changes, the decrease of certain bird species as Bullfinch Pyrrhula pyrrhula and Citril Finch Serinus citrinella may result from population changes at larger scales. The current closure of the landscape represents a threat for several steppe species whose conservation status is unfavourable in Europe. This closure does not result from a decrease in human population and/or in flock number, as observed in many Mediterranean hinterlands. It rather results from a shift from a former extensive pastoralism, where sheep grazed steppe-like grasslands (rangeland grazing), towards a more intensive herding that use hay and cereal foodstocks cultivated on the more productive areas of the farms. To alleviate the observed trends, subsidies should be oriented towards the compensation of a possible loss of income resulting from the maintenance of the traditional extensive pastoralism.

Abstract: Coastal South Africa draws interdisciplinary interests due to the co-occurrence of a rich record for early human behavioral modernity, hyper-diverse vegetation with very high endemism (the Cape Floral Region), and globally influential oceanic and climate systems. High resolution and continuous climate and environmental records are needed to provide the context for the evolution of behavioral modernity and this diverse flora. Here we present the first such record for climate and environmental change from 90 000 to 53 000 years ago from the southern Cape coast. This important time span covers a burst of expression of several indicators of human behavioral modernity, as well as several key cycles in global climate change. Our research location is ideally placed near the location of several critical archaeological sites, near the boundary of the winter and summer rainfall regimes, and close to isotopically distinct floral zones. We used isotopic analysis of precisely dated speleothems to document shifting vegetation and rainfall, and show that the presence of winter rain and C3 grasses waxes and wanes in response to Southern Hemisphere shifts in SSTs and global temperature. When proxies of global temperatures indicate warmer conditions, [delta]18O and [delta]13C indicate more winter rain and more C3 grasses, respectively, and vice versa. This record displays abrupt and short-term changes previously undocumented. It is often argued that the Cape Floral Region partially owes its high diversity to relative climatic stability. Our record shows isotopic variability that at least matches that displayed in the Levantine Mediterranean system, so climatic stability may not have characterized the south coast. One short-lived phase of human technological innovation (the Still Bay) associated with early evidence for behavioral modernity occurs synchronous with an abrupt environmental perturbation. Early modern humans in this region confronted a variable climate and adapted quickly in a manner similar to behaviorally modern humans.

Abstract: Spotted knapweed (Centaurea stoebe ssp. micranthos) is one of the most troublesome rangeland weeds in western North America. As part of a larger investigation evaluating the use of targeted sheep grazing to control spotted knapweed, we examined sheep preference and forage quality of dried spotted knapweed in different phenological stages. We collected spotted knapweed for preference evaluation trials from a sagebrush steppe community near Dubois, Idaho throughout the 1999 growing season and analyzed the plants for nutritional quality. Preference for spotted knapweed was evaluated in a cafeteria trial, where we offered 12 ewes dried and chopped spotted knapweed in rosette, bolting, and flowering/seedset phenological stages. Nutritional value of spotted knapweed was highest in early phenological stages and declined with phenological development. Sheep readily consumed spotted knapweed in all phenological stages; however, rosette and bolting knapweed were generally selected over the flowering/seedset knapweed. Spotted knapweed consumption was related to crude protein, and neutral detergent fiber content of spotted knapweed, yet consumption was not related to cnicin content, a suspected feeding deterrent. This study suggests knapweed is acceptable forage that has adequate nutritional value during the growing season to sustain wild and domestic ungulates.

Abstract: Herbivores can act as dispersal vectors by purposely or accidentally ingesting ripe fruits, and thus endozoochory is one determining factor for plant distribution patterns. The objective of our study was to investigate to what extent plants of major taxonomic groups of the Knersvlakte (Succulent Karoo, South Africa) are endozoochorously dispersed. On three different farms in the central Knersvlakte, dung of domestic herbivores was collected and analysed by the seedling-emergence method. The resulting species composition was compared to the standing vegetation of thirty-four 1000-m2 plots each recorded on one hundred 400-cm2 subplots. Our results show that domestic livestock facilitated the dispersal of taxa characteristic of the Knersvlakte, in particular Aizoaceae. Among the taxa of this family, the local endemic dwarf shrub Drosanthemum schoenlandianum emerged with the highest frequency in dung (14.5% of all seedlings). For the Asteraceae, which are frequent in the standing vegetation of the Knersvlakte, however, endozoochorous dispersal by livestock was only of minor importance. Conservation planning should consider these dispersal patterns on behalf of future population dynamics. The complete exclusion of livestock might change current processes and thus alter vegetation patterns.

Abstract: Summary Poor land condition resulting from unsustainable grazing practices can reduce enterprise profitability and increase water, sediment and associated nutrient runoff from properties and catchments. This paper presents the results of a 6 year field study that used a series of hillslope flume experiments to evaluate the impact of improved grazing land management (GLM) on hillslope runoff and sediment yields. The study was carried out on a commercial grazing property in a catchment draining to the Burdekin River in northern Australia. During this study average ground cover on hillslopes increased from ~35% to ~75%, although average biomass and litter levels are still relatively low for this landscape type (~60 increasing to 1100 kg of dry matter per hectare). Pasture recovery was greatest on the upper and middle parts of hillslopes. Areas that did not respond to the improved grazing management had <10% cover and were on the lower slopes associated with the location of sodic soil and the initiation of gullies. Comparison of ground cover changes and soil conditions with adjacent properties suggest that grazing management, and not just improved rainfall conditions, were responsible for the improvements in ground cover in this study. The ground cover improvements resulted in progressively lower runoff coefficients for the first event in each wet season, however, runoff coefficients were not reduced at the annual time scale. The hillslope annual sediment yields declined by ~70% on two out of three hillslopes, although where bare patches (with <10% cover) were connected to gullies and streams, annual sediment yields increased in response to higher rainfall in latter years of the study. It appears that bare patches are the primary source areas for both runoff and erosion on these hillslopes. Achieving further reductions in runoff and erosion in these landscapes may require management practices that improve ground cover and biomass in bare areas, particularly when they are located adjacent to concentrated drainage lines.

Abstract: Preservation of biodiversity can be at odds with preservation of sociodiversity, i.e., human groups with different cultures, social organization and economic activities coexisting within a region. We analyzed this problem in the Cushamen Reserve, a pastoralist Mapuche aboriginal settlement in Patagonia, Argentina. We found that the current stocking rate of domestic herbivores is twice the rangeland carrying capacity, and this overstocking has resulted in a 20-30% reduction in plant cover, productivity, floristic richness and pastoral value compared to similar sites located on neighboring capitalist farms. The potential economic income of a generic Cushamen farm (625 ha) under the current stocking rate (0.27 sheep units[bullet operator]ha-1) and productive parameters (wool and number of lambs produced per sheep each year and the number of sheep that died or were discarded per year) is above the family poverty line, but this potential may be only rarely achieved due to interannual variability of productive parameters. However, under the carrying capacity, only an improbable combination of 0.84 lambs[bullet operator]sheep-1 yr-1, 5.5 kg wool[bullet operator]sheep-1 yr-1 and a 16% rate of annual sheep discarding would equal the present potential income. Active policies aimed at increasing carrying capacity of the Cushamen Reserve are needed to preserve both bio- and sociodiversity.

Abstract: Soil water repellency, infiltration, and fire severity were evaluated at 235 locations within a sagebrush-steppe ecosystem in southern Idaho, USA, after a 78,000 ha wildfire. Fire frequency in the sagebrush-steppe has increased dramatically in the last century due to the proliferation of introduced annual weeds. Wildfire in shrub-steppe can increase runoff and erosion by decreasing vegetation cover and increasing soil hydrophobicity. Soil water repellency was measured with the water drop penetration time (WDPT) test and relative infiltration rates were measured by the mini-disc infiltrometer (MDI). Shrub-dominated locations showed highest water repellency in areas of moderate fire severity and infiltration rate was inversely related to distance from individual sagebrush plants. Highest water repellency in grass-dominated areas was also associated with moderate fire severity. Likewise, the lowest relative mean infiltration rates occurred in shrub-dominated or grass-dominated areas of moderate fire severity. These findings indicate that land management strategies should be targeted towards moderate fire severity areas.

Abstract: Fire is an important natural disturbance process in many ecosystems, but humans can irrevocably change natural fire regimes. Quantifying long-term change in fire regimes is important to understand the driving forces of changes in fire dynamics, and the implications of fire regime changes for ecosystem ecology. However, assessing fire regime changes is challenging, especially in grasslands because of high intra- and inter-annual variation of the vegetation and temporally sparse satellite data in many regions of the world. The breakdown of the Soviet Union in 1991 caused substantial socioeconomic changes and a decrease in grazing pressure in Russia's arid grasslands, but how this affected grassland fires is unknown. Our research goal was to assess annual burned area in the grasslands of southern Russia before and after the breakdown. Our study area covers 19,000 km2 in the Republic of Kalmykia in southern Russia in the arid grasslands of the Caspian plains. We estimated annual burned area from 1985 to 2007 by classifying AVHRR data using decision tree algorithm, and validated the results with RESURS, Landsat and MODIS data. Our results showed a substantial increase in burned area, from almost none in the 1980s to more than 20% of the total study area burned in both 2006 and 2007. Burned area started to increase around 1998 and has continued to increase, albeit with high fluctuations among years. We suggest that it took several years after livestock numbers decreased in the beginning of the 1990s for vegetation to recover, to build up enough fuel, and to reach a threshold of connectivity that could sustain large fires. Our burned area detection algorithm was effective, and captured burned areas even with incomplete annual AVHRR data. Validation results showed 68% producer's and 56% user's accuracy. Lack of frequent AVHRR data is a common problem and our burned area detection approach may also be suitable in other parts of the world with comparable ecosystems and similar AVHRR data limitations. In our case, AVHRR data were the only satellite imagery available far enough back in time to reveal marked increases in fire regimes in southern Russia before and after the breakdown of the Soviet Union.

Abstract: The Knersvlakte in the Succulent Karoo Biome (South Africa) is known for its high plant diversity and endemism. In the course of establishing a conservation area there, we assessed baseline data for future management. We investigated the effects of grazing on the vegetation in terms of species diversity and composition as well as reproduction of selected species. Data were sampled on four adjacent farms, which were ungrazed, moderately or intensively grazed by sheep and goats. The data were collected in 27 quartz and 24 non-quartz plots, representing two major habitat types of the region. Within each of the 1000-m2 plots, 100 subplots of 400 cm2 size were sampled. ANOVAs revealed that species richness and abundance of endemic species on quartz fields decreased with grazing. Abundance of annuals did not increase significantly due to grazing. Fidelity analyses indicated that species composition differed between grazing intensities and that the ungrazed and moderately grazed plots both contained unique locally endemic habitat specialists. Reproduction of two endemic dwarf shrubs Drosanthemum schoenlandianum and Argyroderma fissum (both Aizoaceae) increased under moderate grazing, which in the case of D. schoenlandianum was interpreted as an effect of grazing. We attribute the low number of seedlings and annuals on the moderately grazed farm to lower seasonal rainfall on these plots. From a conservation perspective, no or moderate grazing appear to be necessary to preserve plant diversity and vegetation patterns, and their underlying processes.

Abstract: Knowing how species respond to fire regimes is essential for ecologically sustainable management. This axiom raises two important questions: (1) what knowledge is the most important to develop and (2) to what extent can current research methods deliver that knowledge? We identify three areas of required knowledge: (i) a mechanistic understanding of species' responses to fire regimes; (ii) knowledge of how the spatial and temporal arrangement of fires influences the biota; and (iii) an understanding of interactions of fire regimes with other processes. We review the capacity of empirical research to address these knowledge gaps, and reveal many limitations. Manipulative experiments are limited by the number and scope of treatments that can be applied, natural experiments are limited by treatment availability and confounding factors, and longitudinal studies are difficult to maintain, particularly due to unplanned disturbance events. Simulation modelling is limited by the quality of the underlying empirical data and by uncertainty in how well model structure represents reality. Due to the constraints on large-scale, long-term research, the potential for management experiments to inform adaptive management is limited. Rather than simply recommending adaptive management, we define a research agenda to maximise the rate of learning in this difficult field. This includes measuring responses at a species level, building capacity to implement natural experiments, undertaking simulation modelling, and judicious application of experimental approaches. Developing ecologically sustainable fire management practices will require sustained research effort and a sophisticated research agenda based on carefully targeting appropriate methods to address critical management questions.

Abstract: Grazing with livestock is a common feature of nature and rangeland management. Although both aim at different, seemingly opposing goals, i.e. maintenance of biodiversity values versus maximization of animal production, they nonetheless have a common interest in maintaining the rangeland or natural environment in a state that ensures either the first or the second goal. In order to accomplish an effective and efficient grazing management, in terms of grazer density, grazer composition, grazing seasonality, and to prevent under- and overgrazing, a grazing capacity model (GCM) was developed, that should be applicable in both rangeland and nature conservation management conditions and that takes spatio-temporal environmental variation into account. This spatio-temporally dynamic model considers crucial variables at both the terrain and the grazer level, such as (seasonally) fluctuating forage yield, forage quality, plant palatability, accessibility of the area, soil erosion vulnerability, animal nutritive requirements, animal behaviour and general habitat condition. It predicts the optimal grazer species and density, taking into account the seasonal variation in animal needs and fluctuating terrain characteristics. A sensitivity analysis was conducted to define each parameter's relative impact on the final outcome of the model. We present the GCM outline and illustrate the functionality of this model for Shetland ponies and Highland cattle, grazing in a temperate coastal dune environment. According to the model, seasonal fluctuations in optimal grazer densities occur: the area can support higher densities in summer and autumn than it can during winter and spring. With the current density of grazing animals and the choice for year-round grazing at non-fluctuating animal densities, the model consequently predicts overgrazing in winter and undergrazing in summer and autumn. Both undergrazing and overgrazing scenarios might lead to non-sustainable situations in the future.

Abstract: The north-central semiarid region of Mexico has been exposed to systematic grazing since colonial times. The grazing impact on rangelands has degraded soils and reduced diversity and productivity. The most common and detrimental cause of soil degradation is soil erosion which destroys chemical, physical and biological properties. To determine the effect of grazing systems on rangelands, several studies were performed. Such studies included a description of soil profiles to categorize degradation and the evaluation of water erosion changes due to further degradation processes under grazing systems (rotational, RG and continuous, CG). The study was carried out on a rangeland of the ejido Pánuco, Zacatecas, from 2002 to 2005. Soil degradation was classified by identifying 6 groups with similar soil profiles (GSSP) which were described as: (1) low degradation soil; (2) medium degradation soil with A horizon lost; (3) high degradation soil without A and B horizons lost; (4) high degradation soil with in situ development; (5) high degradation soil with calcareous material; and (6) high degradation soil without development, which is a very shallow soil above the parental material. Further degradation was determined by soil erosion measurements performed in the study area and the surroundings. With respect to soil losses their values were systematically less for the RG system under the native vegetation conditions studied (P < 0.01). Changes in the production systems may imply a reconversion of the system. Some changes include a modification in the intensity of use of rangelands, starting with a new grazing system, as well as changes in technology which may be simulated by GIS.

Abstract: Burnt daga structures in Iron Age villages serve as proxies for severe drought on the plateau of southern Africa. The distribution of burnt daga remains in two other rainfall areas, KwaZulu-Natal and the Inter-Tropical Convergence Zone over Zimbabwe, Zambia and Malawi, establishes a sequence of simultaneous burnings that parallels the severe droughts recorded for the interior plateau. These widespread correspondences suggest a common cause. Another correspondence with natural proxy data from South America indicates that intensive El Niño events most likely caused the droughts.

Abstract: This paper reviews current knowledge on changes in carbon stocks upon land use conversion in the Brazilian Cerrado. First, we briefly characterize the savanna ecosystem and summarize the main published data on C stocks under natural conditions. The effects of increased land use pressure in the Cerrado and current uncertainties of estimations of changes in land cover and land use are reviewed next. Thereafter, we focus on soil organic carbon (SOC) dynamics due to changes in land use, particularly conversion to pastures and soybean-based cropping systems, and effects of management practices such as soil fertilization, crop rotations and tillage practices. Most studies considered here suggest that more intensive agriculture, which include no-till practices and the implementation of best or recommended management practices (RMP), reduces SOC losses after land use conversion from conventional tillage-based, monocropping systems; however, these studies focussed on the first 0.3 m of soil, or less, and seldom considered full carbon accounting. To better estimate possible global warming mitigation with agriculture in the Cerrado more comprehensive studies are needed that analyse fluxes of the biogenic greenhouse gases (GHG; CO2, N2O and CH4) to determine the net global warming potential (GWP). Follow up studies should include the application of an integrated modelling system, comprised of a Geographic Information System (GIS) linked to dynamic modelling tools, to analyse SOC dynamics and make projections for possible changes in net C flows in the Cerrado region upon defined changes in soil use and management.

Abstract: Here we describe the fine root distribution of trees and grasses relative to soil nitrogen and water profiles. The primary objective is to improve our understanding of edaphic processes influencing the relative abundance of trees and grasses in savanna systems. We do this at both a mesic (737 mm MAP) site on sandy-loam soils and at an arid (547 mm MAP) site on clay rich soils in the Kruger National Park in South Africa. The proportion of tree and grass fine roots at each soil depth were estimated using the [delta]13C values of fine roots and the [delta]13C end members of the fine roots of the dominant trees and grasses at our study sites. Changes in soil nitrogen concentrations with depth were indexed using total soil nitrogen concentrations and soil [delta]15N values. Soil water content was measured at different depths using capacitance probes. We show that most tree and grass roots are located in the upper layers of the soil and that both tree and grass roots are present at the bottom of the profile. We demonstrate that root density is positively related to the distribution of soil nitrogen and negatively related to soil moisture. We attribute the negative correlation with soil moisture to evaporation from the soil surface and uptake by roots. Our data is a snapshot of a dynamic process, here the picture it provides is potentially misleading. To understand whether roots in this system are primarily foraging for water or for nitrogen future studies need to include a dynamic component.

Abstract: This study evaluated the dynamics of bush cover in relation to the role played by seasonally grazed traditional enclosures compared to grazed rangelands. The result showed that herbaceous biomass was higher in enclosures than in the open grazed areas. Enclosures also showed more diversity and evenness of herbaceous species than open grazed areas. Herbaceous species richness declined with increased age of enclosures compared to the recent and medium age of enclosures. The frequencies of herbaceous species were relatively similar in both management and across enclosures age. A total of 26 herbaceous and 29 woody species were recorded within both enclosures and open grazed sites. Of the total woody plants, 38% of the species were invasive, while the rest (i.e. 62%) were non-invasive. Generally, grazed areas were less threatened by invasive species than enclosures. The density of invasive woody population (63.4% of the total density of woody population) was 2665 stems ha-1. Commiphora africana accounted for most of the increase in cover of woody population, on average contributing 86% to the total invasive woody cover in the study area. A reintroduction of fire is recommended together with the integration of traditional range enclosures in order to control invasion of bush encroachment.

Abstract: Ants are a prominent invertebrate group used to assess ecological change in response to disturbance. Their application as a bioindicator group has been particularly widespread in Australia, and a recent comprehensive review of their responses to environmental disturbance identified a range of consistent and predictable patterns. Here I conduct a literature review of the responses of ants to grazing globally, and specifically test whether key patterns identified in the review of ant responses to disturbance in Australia apply globally. The patterns tested were (1) soil and vegetation type are primary determinants of ant community composition, and often have a far greater effect on ant community composition than disturbance, (2) disturbance induces species compositional change, but does not necessarily affect overall species richness or abundance, (3) a species' response is not necessarily consistent across habitats because of variation in inherent habitat suitability, and (4) approximately one quarter to one half of species that are common enough for statistical analysis have significant responses to disturbance. All these patterns were found to hold true for grazing studies worldwide. All but three studies sampling multiple soils/vegetation types found the influence of these variables to override grazing effects. Community composition changed consistently, yet the responses of total ant abundance and species richness were highly inconsistent. All studies that analysed species-level data on multiple soils/vegetation types, showed mixed responses to grazing across habitats. On average, 33% of tested species had statistically significant differences across treatments. This is the first such formulation of global patterns for any terrestrial invertebrate group for their use in bioindication, and provides valuable support to the use of ants as indicators of ecological disturbance. The challenge now is to provide a predictive understanding of this context dependency, as well as to improve the precision of the predictive responses. The confirmation of global patterns to grazing presented here represents a first step in developing the valuable contribution that ants can provide to rangeland monitoring systems.

Abstract: Rangeland degradation, a worldwide problem, is serious in China, especially in the Northern provinces. To assess the pastoralists' perceptions toward rangeland trend and degradation, a survey was conducted in Ningxia, North China. Data were collected from a total of 284 pastoralists in six Ningxia counties. Findings showed that the majority of respondents believe the rangelands in Ningxia have been degraded, although there are some disparities among the counties that illustrate differing severity of degradation. Findings also clarified that the pastoralists have more knowledge about the "technical" and "supportive" aspects of conditions, while remaining less aware of "economic" and "management" factors of this issue. Yet, a high disparity was revealed between pastoralists' perceptions among the counties in this study. The correlation matrix showed that most of their perceptions do not act independently. Findings also showed that those pastoralists who believe that their rangeland trend is "improved" have broader management and social perceptions than those who believe their rangeland is "degraded". Finally, correlation analysis showed that the management and social perceptions have a negative correlation with degradation severity. Based on the findings, recommendations for possible interventions through extension/educational programs to diminish rangeland degradation are made. The programs are suggested to be presented in three packages including "management", "social", and "economic" issues in rangeland degradation.

Abstract: Herbivores are regulated by predation under certain environmental conditions, whereas under others they are limited by forage abundance and nutritional quality. Whether top-down or bottom-up regulation prevails depends both on abiotic constraints on forage availability and body size, because size simultaneously affects the risk of predation of herbivores and their nutritional demands. Consequently, ecosystems composed of similar species can have different dynamics if they differ in resource supply. Here, we use large herbivore assemblages in African savanna ecosystems to develop a framework that connects environmental gradients and disturbance patterns with body size and trophic structure. This framework provides a model for understanding the functioning and diversity of ecosystems in general, and unifies how top-down and bottom-up mechanisms depend on common underlying environmental gradients.

Abstract: The arid and semi-arid sagebrush-grass ecosystem occupies a substantial portion of rangelands in the western United States. Using remote sensing techniques to map the percent of sagebrush, grass/forb, and bare ground components is necessary for forage production estimation and natural resource management over large areas. However optical data have significant deficiencies in these ecosystems because of exposed bright soil, spectrally-indeterminate vegetation, and a large dead vegetation component. Radar data also have deficiencies caused by factors such as antenna pattern calibration, local incidence angle (LIA), soil moisture, and surface roughness. With the complementary vegetation information gained from optical data and radar data, these two datasets were fused to estimate 10-m sagebrush, grass, and bare ground percent cover in the non-forested areas of Yellowstone National Park, which is a representative native western rangeland ecosystem of the US. The datasets were processed to resolve the issues of antenna pattern calibration and LIA effect. Peak green Landsat, late fall Airborne Visible and Infrared Imaging Spectrometer (AVIRIS), and Airborne Synthetic Aperture Radar (AirSAR) data were fused in this analysis. AVIRIS, Landsat, AirSAR and elevation data were used to segment the study area into two main subcategories of "pure grass" and "mixed sagebrush and grass". Landsat Tasseled Cap Greenness (LTCG) was used to retrieve bare land and grass percentages in pure grass areas. In the areas with mixed grass and sagebrush, standardized LTCG and radar Cvv were used to derive the vegetation cover percentage, and the ratio of standardized LTCG and radar Lhv was further used to calculate the relative abundance of sagebrush and grass. Comparison between the field and remote sensing estimations shows the correlation coefficients were 0.838, 0.746, and 0.830 for bare land, grass, and sagebrush, respectively. When grouped into three discrete categories of "low", "medium", and "high", the overall accuracies were 79.4%, 75.9%, and 77.6%, respectively. Our study shows the potential for application of global spaceborne C- and L-band radar and optical data fusion for large-area rangeland monitoring.

Abstract:

Abstract: An operational procedure is presented that allows detecting active fires based on information from Meteosat-8/SEVIRI over Africa. The procedure takes advantage of the temporal resolution of SEVIRI (one image every 15 min), and relies on information from SEVIRI channels (namely 0.6, 0.8, 3.9, 10.8 and 12.0 µm) together with information on illumination angles. The method is based on heritage from contextual algorithms designed for polar, sun-synchronous instruments, namely NOAA/AVHRR and MODIS/TERRA-AQUA. A potential fire pixel is compared with the neighboring ones and the decision is made based on relative thresholds as derived from the pixels in the neighborhood. An overview is provided of results obtained for January and July 2007, respectively over Northern Africa (NAfr) and Southern Africa (SAfr), paying special attention to the spatial and temporal distribution of active fires. In both NAfr and SAfr, two types of vegetation clearly dominate in terms of fire activity, namely tree-covered areas, containing 40% of total fires observed, and shrub-covered areas, with 25% (19%) of total fires in NAfr (SAfr). However, marked differences were also to be found between the two regions; more than two-thirds (70%) of fires in SAfr were observed in land cover classes dominated by trees but the proportion is much lower (40%) in the case of NAfr. The duration of active fires in both regions tends to follow two-parameter generalized Pareto distributions, with both the scale and the shape parameters presenting very similar values for NAfr and SAfr. An assessment of the robustness of the algorithm, consistency of results and added value of the product was made by studying the daily cycle of fire activity over two regions located in northern and southern hemisphere Africa and by means of systematic comparisons against fire incidence reported in previous works and against hot spots extracted from the global daily active fire product developed by the MODIS Fire Team. The observed fire incidence by land cover class compares well with the results reported in previous works and it is shown that there is an overall coherence between results obtained from SEVIRI and MODIS when adequate spatial and temporal scales are chosen when performing the comparison. Data from MODIS and SEVIRI may be viewed as complementary, the latter having the added value of providing a much finer temporal resolution that allows uncovering certain aspects of fire behavior, namely the characterization of daily fire cycles.

Abstract: This study set out to generate estimates of the standing perennial biomass for six different vegetation types, and associated upland and lowland habitats, across the altitudinal gradient presented by the Kamiesberg mountain range in the Namaqualand region of the Northern Cape Province of South Africa. Volume-biomass regressions, established for 94 perennial species accounting for 70-80% of the plant cover, were used to generate these estimations. Comparisons to other studies give similar findings, corroborating the method adopted. Biomass was found to vary significantly in relation to the altitudinal, and associated rainfall, gradient, as well as by habitat type where the rocky uplands have considerably more biomass that the sandy lowland habitats. An examination of the impact of sustained heavy grazing associated with a communal rangeland on this standing perennial biomass, showed a significant decrease in on the lowland habitats. This loss in biomass is principally of palatable species, with no evidence of a response in terms of perennial biomass. These findings point to degradation on the lowland habitats of the communal rangeland, with negative consequences for livestock farmers in the region.

Abstract: Direct effects of herbivores on plants and on the physical environment can accelerate inorganic nitrogen (N) flow in grassland ecosystems. This study compares N content and N mineralization in the soil beneath plants of Stipa tenuis growing in adjacent grazed or ungrazed areas at three sites in central Argentina. Grazed areas had a long history of heavy, year-long grazing by cattle (6-8 ha cattle-1), whereas ungrazed areas had been excluded from grazing by large herbivore for five to ten years. N content and N mineralization was measured in the soil under plants (n = 10 per grazing treatment and per site) of the studied species at monthly intervals along an annual growing cycle. N mineralization was measured both in situ and in laboratory under optimal conditions of moisture and temperature. We did not found a significant effect of grazing on N content or on N mineralization in the soil beneath S. tenuis all over the studied period. Sustained, long-term overgrazing by domestic livestock, through plant and soil deterioration may either counterbalance or override accelerating N cycling attributed to prudent grazing (i.e., grazing that favours plant productivity and persistence) in managed grasslands.

Abstract: Riparian zones are exposed to increasing pressures because of disturbance from agricultural and urban expansion and overgrazing. Accurate and cost-effective mapping of riparian environments is important for baseline inventories and monitoring and managing their functions associated with water quality, biodiversity, and wildlife habitats. In this study, we integrate remotely sensed light detection and ranging (LiDAR) data and high spatial resolution satellite imagery (QuickBird-2) to estimate riparian biophysical parameters and land cover types in the Fitzroy catchment in Queensland, Australia. An object based image analysis (OBIA) was adopted for the study. A digital terrain model (DTM), a tree canopy model (TCM) and a plant projective cover (PPC) map were first derived from the LiDAR data. A map of the streambed was then produced using the DTM information. Finally, all the LiDAR-derived biophysical map products and the QuickBird image bands were combined in an OBIA to (1) map the following land cover types: riparian vegetation, streambed, bare ground, woodlands and rangelands; (2) determine the distribution of overhang vegetation within the streambed; and (3) measure the width of both the riparian zone and the streambed. The combined use of both datasets allowed accurate land cover mapping, with an overall accuracy of 85.6%. The estimated widths of the riparian zone and the streambed showed strong correlation with the actual field measurements (r = 0.82 and 0.98 respectively). Our results show that the combined use of LiDAR and high spatial resolution imagery can potentially be used for the assessment of the riparian condition in a tropical savanna woodland riparian environment. This work also shows the capacity of OBIA to assist in the assessment of the composition of the riparian environment from multiple image datasets.

Abstract: Cheatgrass (Bromus tectorum L.) has come to dominate millions of hectares of rangeland in the Intermountain western United States. Previous studies have hypothesized that one mechanism conferring a competitive advantage to this species is the ability to germinate rapidly at low temperatures in the fall, winter and spring and, therefore, initiate growth and establishment more rapidly than more desirable perennial bunchgrass species. In this experiment, we developed thermal-germination-response models for multiple seedlots of cheatgrass and five perennial grass species. We conducted sensitivity analysis on potential-cumulative-germination response to a 38-year simulation of field-variable conditions of seedbed temperature and moisture. Cheatgrass uniformly germinated at a higher rate, and required significantly less time to complete germination than any of the perennial species for all but the slowest seed subpopulations. A germination-rate-sum index was used to integrate relative response characteristics over time. This index showed that germination rate of the most rapidly germinating subpopulations of cheatgrass was 2-5 times higher than for the other species tested. Model simulations of this type provide a more ecologically relevant basis for seedlot evaluation as they allow comparisons across a wide range of potential conditions that may be experienced in the field.

Abstract: Rangelands of the Qinghai-Tibetan plateau (QTP), although sparsely populated and contributing little to China's overall economy, play an important environmental role throughout Asia. They contain high biodiversity values and can also potentially provide China with a source of cultural and geographic variety in the future. Chinese government reports paint a gloomy picture, considering vast portions of the QTP degraded and blaming irrational overstocking of livestock as the principal culprit. Global climate change, population increases, and "rodent" damage are also invoked as causes of rangeland degradation. In contrast, some Western observers claim that traditional pastoral practices were sustainable, and identify either previous or more recent state policies as the cause of degradation. Chinese governments at national and provincial levels have initiated a number of sometimes-conflicting and confusing policies aimed, at least nominally, at restoring rangeland productivity. On the basis of a comprehensive literature review, I argue that the extent and magnitude of rangeland degradation on the QTP remains largely unknown because monitoring programs have been subjective and poorly documented. Further, I argue that causes of degradation remain uncertain, often because hypotheses have been articulated too vaguely to test. No phenomena that have been hypothesized as contributing to rangeland degradation on the QTP currently enjoy unequivocal support. Where over-stocking is clearly causing damage, we lack sufficient understanding of current socio-ecological systems to identify ultimate and proximate drivers of pastoralist behavior, and thus policy initiatives aimed at sustainability may well fail.

Abstract: Prescribed burning is a commonly advocated and historical practice for control of woody species encroachment into grasslands on all continents. However, desert grasslands of the southwestern United States often lack needed herbaceous fuel loads for effective prescriptions, dominant perennial graminoids may have poor fire tolerance, and some systems contain fire-tolerant invasive species. We examined long-term vegetation responses of a black grama (Bouteloua eriopoda Torr.) grassland that had been invaded by honey mesquite (Prosopis glandulosa) following a single prescribed burn. Vegetation responses to a 1995 prescribed burn were evaluated in a replicated randomized complete block design with a 2 � 2 factorial treatment structure. Treatments were prescribed burning and livestock exclusion for both a grassland-dominated and a shrub-encroached grassland state within a complex of sandy and shallow sandy ecological sites. Vegetation responses were measured in 2008, 13 years after the burn treatment application. Neither black grama basal cover nor honey mesquite canopy cover were responsive (p < 0.05) to any treatment. A single prescribed burn would be ineffective as a shrub control practice in this environment. Repeated but infrequent prescribed burning within shrub-encroached vegetative states, when used in combination with managed grazing, may be the management required for a transition to desert grassland states within these ecological sites.

Abstract: Abstract Questions: Can prescribed fire restore C4 perennial grasses in grassland ecosystems that have become dominated by fire-resistant C3 shrubs (Prosopis glandulosa) and C3 grasses? Do fires in different seasons alter the direction of change in grass composition? Location: Texas, USA. Methods: We quantified short- and long-term (12 yr post-fire) herbaceous functional group cover and diversity responses to replicated seasonal fire treatments: (1) repeated-winter fires (three in 5 yr), (2) repeated-summer fires (two in 3 yr), and (3) alternate-season fires (two winter and one summer in 4 yr), compared with a no-fire control. Results: Summer fires were more intense than winter fires, but all fire treatments temporarily decreased Prosopis and C3 annual grass cover. The alternate-season fire treatment caused a long-term increase in C4 mid-grass cover and functional group diversity. The repeated-summer fire treatment increased C4 short-grass cover but also caused a long-term increase in bare ground. The repeated winter fire treatment had no long-term effects on perennial grass cover. Mesquite post-fire regrowth had increasingly negative impacts on herbaceous cover in all fire treatments. Conclusions: Summer fire was necessary to shift herbaceous composition toward C4 mid-grasses. However, the repeated-summer fire treatment may have been too extreme and caused post-fire herbaceous composition to �over-shift� toward less productive C4 short-grasses rather than C4 mid-grasses. This study provides some of the first long-term data showing a possible benefit of mixing seasonal fires (i.e., the alternate-season fire treatment) in a prescribed burning management plan to restore C4 mid-grass cover and enhance overall herbaceous diversity.

Abstract: Precipitation quantity and timing have been shown to fundamentally influence grassland ecosystem CO2 exchange by both model simulation and field observation. Carbon dioxide exchange and patterns of variation (magnitude and timing) in precipitation were observed to determine their relationship in typical steppe in Inner Mongolia Plateau during four years (2003-2006) with different rainfall patterns. The response of ecosystem-level CO2 fluxes to rainfall pulse events was also examined. The four years studied were classified into three levels of rainfall amount (100%, 2004; reduced by 70% in 2005 and by 45% in 2006 compared with 2004) and two temporal patterns of rain events (average temporal patterns in 2004 and altered precipitation timing in 2003, a year with precipitation fell during the first half of the growing season, compared with 2004). The grassland ecosystem switched from a carbon sink (2004) to carbon sources (2005 and 2006) under reduced rainfall amounts. Carbon sink reduced by 34% under variational rainfall timing conditions (2003). There was a significant positive correlation between annual rainfall and above-ground NPP across the study (P = 0.05, r2 = 0.9). Antecedent soil water before rainfall pulse and rainfall pulse size are important in controlling the response of CO2 exchange to rainfall in this steppe. After rainfall pulse events, CO2 fluxes had 4 to 5 days of system-level hysteresis and the increase degree of CO2 exchange was different among the four years. Precipitation pulse size not only affected the duration of CO2 fluxes, but also instant flux rate. Our results suggest that CO2 exchange in temperate steppe will be more sensitive to altered rainfall timing and more affected by changes in rainfall quantity, with a longer dry season resulting in significant C losing from Eurasia grassland in Inner Mongolia Plateau.

Abstract: Remote sensing imagery needs to be converted into tangible information which can be utilised in conjunction with other data sets, often within widely used Geographic Information Systems (GIS). As long as pixel sizes remained typically coarser than, or at the best, similar in size to the objects of interest, emphasis was placed on per-pixel analysis, or even sub-pixel analysis for this conversion, but with increasing spatial resolutions alternative paths have been followed, aimed at deriving objects that are made up of several pixels. This paper gives an overview of the development of object based methods, which aim to delineate readily usable objects from imagery while at the same time combining image processing and GIS functionalities in order to utilize spectral and contextual information in an integrative way. The most common approach used for building objects is image segmentation, which dates back to the 1970s. Around the year 2000 GIS and image processing started to grow together rapidly through object based image analysis (OBIA - or GEOBIA for geospatial object based image analysis). In contrast to typical Landsat resolutions, high resolution images support several scales within their images. Through a comprehensive literature review several thousand abstracts have been screened, and more than 820 OBIA-related articles comprising 145 journal papers, 84 book chapters and nearly 600 conference papers, are analysed in detail. It becomes evident that the first years of the OBIA/GEOBIA developments were characterised by the dominance of [`]grey' literature, but that the number of peer-reviewed journal articles has increased sharply over the last four to five years. The pixel paradigm is beginning to show cracks and the OBIA methods are making considerable progress towards a spatially explicit information extraction workflow, such as is required for spatial planning as well as for many monitoring programmes.

Abstract: The relative abundance and distribution of trees in savannas has important implications for ecosystem function. High spatial resolution satellite sensors, including QuickBird and IKONOS, have been successfully used to map tree cover patterns in savannas. SPOT 5, with a 2.5 m panchromatic band and 10 m multispectral bands, represents a relatively coarse resolution sensor within this context, but has the advantage of being relatively inexpensive and more widely available. This study evaluates the performance of NDVI threshold and object based image analysis techniques for mapping tree canopies from QuickBird and SPOT 5 imagery in two savanna systems in southern Africa. High thematic mapping accuracies were obtained with the QuickBird imagery, independent of mapping technique. Geometric properties of the mapping indicated that the NDVI threshold produced smaller patch sizes, but that overall patch size distributions were similar. Tree canopy mapping using SPOT 5 imagery and an NDVI threshold approach performed poorly, however acceptable thematic accuracies were obtained from the object based image analysis. Although patch sizes were generally larger than those mapped from the QuickBird image data, patch size distributions mapped with object based image analysis of SPOT 5 have a similar form to the QuickBird mapping. This indicates that SPOT 5 imagery is suitable for regional studies of tree canopy cover patterns.

Abstract: The central role played by livestock in the livelihoods of rural households in the developing world is seldom fully appreciated by policy makers, development agencies and donors. Knowledge gaps in the geographic distribution and environmental determinants of farming systems, especially if viewed through the livestock lens, compound this problem. We have produced a map of pastoral, agro-pastoral and mixed farming systems across Eastern Africa, by analysing datasets collected in the framework of livelihood analysis. Input data were gathered between 2000 and 2007 by various emergency and development agencies for Djibouti, Eritrea, Kenya, Somalia, Uganda and parts of Ethiopia and Sudan. A quantitative definition of the production systems is adopted, based on the ratio of livestock- to crop-derived income. The resulting livelihood-based map of livestock production systems was compared through correspondence analysis to an alternative livestock production systems map, produced independently from environmental data. Convergence between the two mapping approaches was evident. The geographic distribution of the livestock production systems was also modelled using multivariate analysis of remotely sensed and other geospatial datasets. Models show high statistical accuracy, and were thus used to fill the gaps in the observed distribution of livestock production systems. Finally, selected environmental factors underpinning the systems (agro-climatology, human and livestock populations and land cover) were analysed in detail, enabling the livestock production systems to be characterized in terms of them. The regional scope of the map, as well as its direct link with a vast amount of livelihood information, render it a valuable tool for a range of development and research applications, including those related to global change.

Abstract: Spanning the period from ~74-58 ka, and being broadly coeval with marine oxygen isotope stage 4 (MIS 4), the Still Bay and Howiesons Poort industries represent important phases in the development of the material culture of early modern humans. How and why these industries occurred when they did, however, remain matters for speculation. A key element of this debate has been the question of what role environmental change during the early stages of the last glacial period may have had on influencing human activity. Unfortunately, well-dated palaeoenvironmental evidence from this period is limited, and the debate has, out of necessity, been driven by the application of conceptual models of environmental change, many of which associate colder and warmer global climates with increased aridity and humidity respectively. In this paper, the regional marine and terrestrial evidence is synthesised to create an evidence-based palaeoenvironmental context. Based on the information available to date, it appears that rather than being characterised by dry conditions, MIS 4 was a period of relatively cool, moist climates, the ubiquity of which transcends the modern regional climate boundaries. It is suggested that orbital parameters at this time created greater interaction between tropical and temperate circulation systems, bringing more moisture to the subcontinent. These findings highlight the distinct nature of southern African climate systems, and caution against the application extra-regional conceptual models or inferring linear relationships with polar records.

Abstract: Presented here are stable nitrogen isotope data from a rock hyrax (Procavia capensis) middens from northwestern Namibia that record a series of rapid aridification events beginning at ca. 3800 cal yr BP, and which mark a progressive decrease in regional humidity across the Holocene. Strong correlations exist between this record and other terrestrial and marine archives from southern Africa, indicating that the observed pattern of climate change is regionally coherent. Combined, these data indicate hemispheric synchrony in tropical African climate change during the Holocene, with similar trends characterising the termination of the [`]African Humid Period' (AHP) in both the northern and southern tropics. These findings run counter to the widely accepted model of direct low-latitude insolation forcing, which requires an anti-phase relationship to exist between the hemispheres. The combined dataset highlights: 1) the importance of forcing mechanisms influencing the high northern latitudes in effecting low-latitude climate change in Africa, and 2) the potential importance of solar forcing and variations in the Earth's geomagnetic shield in determining both long-term and rapid centennial-scale climate changes, identifying a possible mechanism for the variations marking the AHP termination in both the southern and northern tropics.

Abstract: Can a payment for flows of ecosystem goods and services system, following appropriate management and restoration of natural capital produced in rural areas of a developing country, be developed in a way that benefits communities, the commercial sector and the environment? This fundamental question acts as rationale for conducting an in-depth assessment as to whether the development of markets for ecosystems is both appropriate and sufficient when dealing with the restoration of natural capital of two degraded study areas within the Maloti-Drakensberg mountain range in southern Africa, which is a fire-prone grasslands ecosystem. The mountain range is South Africa's most strategic source of fresh water. While occupying less than 5% of South Africa's surface area, it produces 25% of the country's runoff through rivers, major dams, and national and international inter-basin transfers. Addressing the question, the study develops an integrated hydrology-ecology-economic model based on the functional relationships between these three aspects in managing and restoring the natural capital of the two study areas. It was found that the benefits of introducing improved management practices exceeds cost in low to medium degraded quinaries, but not in heavily degraded quinaries. The economic return on the water (baseflow) produced by such a system of improved land use management, however, far exceeds that of conventional (construction-based) water development programmes and offers meaningful economic and market development opportunities.

Abstract: We revisited a growth-form removal experiment after 12 years with the aim to compare the long-term population responses of three shrub species. Specifically, we were interested to know if the resource partitioning and plant interactions act as complementary mechanisms of the shrub-grass coexistence. In 1983 different plots from grass-shrub Patagonian steppes were submitted to three treatments: control, grass-, and shrub-removal during three consecutive years. In 1997 we studied nine plots from the original experiment and recorded all shrubs to compare shrub density, population size structure, vitality, spatial patterns and neighbourhood interferences of three native and co-dominant shrub species: Mulinum spinosum, Senecio filaginoides, and Adesmia volckmanni. After 12 years of recovery, shrubs as a growth-form group, fully re-established in plots where they were removed and attained 75% higher density in grass-removal plots than in control plots. However, long-term population responses of Mulinum, Senecio, and Adesmia to removals were distinctive. On the other hand, negative and positive interferences among shrub species and between shrubs and grasses generated a complex network. Morphological and functional differences in shrub and grass species and their interactions at population level and long-term could be a key to achieve a better comprehension of shrub-grass coexistence from semi-arid ecosystems.

Abstract: Hyrax middens are unique environmental archives with the potential to provide unprecedented high-resolution palaeoenvironmental records, particularly in the arid regions of southern Africa. This study provides the first detailed characterisation of the organic matter composition of hyraceum and aims to identify biomarker evidence capable of providing new or supplementary palaeoenvironmental data from these novel archives. Pyrolysis gas chromatography mass spectrometry reveals hyraceum to be dominated by nitrogen-containing aromatic compounds, notably benzamide. This is almost certainly derived directly from the hyrax urine and is probably the main source of nitrogen as measured in bulk [delta]15N measurements. Solvent-extractable lipids comprise homologous suites of long-chain n-alkanes (C24-C34) and n-alkanols (C16-C26), characteristic of higher plant leaf waxes, along with an abundance of animal-derived sterols, higher plant sterols and terpenoids; as well as the ubiquitous benzamide. n-alkane distributions and compound specific [delta]13C clearly differentiate samples from the C3 vegetation dominated Cape Floristic Region, and the more arid, C4 grass-rich savannas of central Namibia (Klein Spitzkoppe). Distinct changes in n-alkane distribution and [delta]13C are observed within the Spitzkoppe midden; most notably the mid to late Holocene period (c. 6000-2000 cal yr BP), which records a progressive reduction in grass-derived organic matter inputs. Based on the animal's feeding behaviour and contemporary site ecology, a phase of increasing aridity is inferred, which is consistent with other proxy data from this site (e.g. bulk [delta]15N). The excellent preservation of plant and animal biomarkers suggests that there is significant potential for midden-derived biomarkers to provide long-term palaeoenvironmental proxies.

Abstract: Grassland vegetation can provide visual cover for terrestrial vertebrates. The most commonly used method to assess visual cover is the Robel pole. We test the use of digital photography as a more accurate and repeatable method. We assessed the digital photography method on four forage grassland species (Pseudoroegneria spicata, Festuca campestris, Poa pratensis, Achnatherum richardsonii). Digital photos of 2-dimensional cutout silhouettes of three bird species sharp-tailed grouse, western meadowlark and savannah sparrow were used to model the impact of clipping (i.e., grazing) on visual cover. In addition, photos of artificial voles were used to model litter on cover available to small mammals. Nine sites were sampled and data were analyzed by the dominant grass species in each study plot. Regression analysis showed that digital photos (r2 = 0.62) were a better predictor than the Robel pole (r2 = 0.26) for assessment of cover. Clipping heights showed that clipping at less than 15 cm left the silhouettes 50% exposed. Digital photo analysis revealed that visual cover was affected by the type of grass species, with F. campestris > P. pratensis > A. richardsonii > P. spicata. Biomass and litter were both positively related to cover for small mammals.

Abstract: A 0.6-m-long horizontal core from a stalagmite in the entrance area of Wonderwerk Cave in South Africa, a National Heritage Site, has provided a 35 ka record of environmental change. A pollen sequence from the stalagmite, and two animal dung deposits, is longer and more detailed for the end of the Pleistocene than previous palynological reports from the southern Kalahari region. This pollen record closely matches information from spring peats at Wonderkrater in Northern Province indicating that speleothem pollen can provide reliable paleovegetation data. The [delta]18O and [delta]13C records resemble those from Cold Air Cave in Northern Province and parallel variations in Greenland Ice Sheet GISP2 paleotemperature. This indicates that past climate changes in southern Africa were linked to changes in global atmospheric and oceanic circulation patterns possibly triggered by conditions in the North Atlantic region. The Wonderwerk data suggest wetter conditions at ca. 33 ka, from 23 to 17 ka, and from 4 ka to present. Conditions were drier 17-13 ka, when microstromatolitic carbonate was deposited on the flank of the stalagmite, and possibly also during depositional hiatuses from 33 to 23 ka and 13 to 4 ka.

Abstract: We used dendroecological techniques to date fire scars in woody species growing in a subtropical savanna of the Argentine Chaco dry forests, and to explore the temporal trends of fire with rainfall variability at different temporal scales during the 20th century. Eight sampling sites were located along an ecotone between savanna and a dry forest, and a composite chronology was developed for a savanna, based on a total of 21 fire dates. The mean fire frequency was 0.18 fires year-1 and the mean fire interval was 3.3 years. The period post 1971 (which had 22% more rainfall) experienced a fire frequency more than two times higher than the period 1925-1970 (p < 0.05). Decadal fire frequency was correlated to 10-years moving average rainfall (R2 = 0.58). Superposed Epoch Analysis showed that fires occur during years of above-average rainfall, and extensive fires tend to follow two years of above-average rainfall, all these associations being statistically significant. These results indicate a climatic control of fire regime, associated to enhanced fine fuels production during years of high rainfall, and imply that regional increase in rainfall associated to global changes in atmospheric circulation are affecting local ecosystems by significantly changing their disturbance regime.

Abstract: Coastal social ecological systems in eastern Africa are subject to a range of environmental, social and economic changes. They are already vulnerable to these multiple stressors, and the impacts of climate change are likely to further exacerbate their vulnerabilities. Some of these impacts may be observed and experienced already. The analysis presented in this paper is based on mixed methods empirical research exploring local perceptions of recent changes at four sites in coastal Tanzania and Mozambique. People recognise and rank a number of climate and non-climate stressors which have contributed towards more risky and less diverse livelihoods. Importantly, regional and international policy initiatives - in the form of river basin management in Mozambique and South Africa, and development of a Marine Protected Area in Tanzania - are perceived to further erode resilience and exacerbate vulnerabilities. We suggest this is a form of policy misfit, where policies developed to address a specific issue do not take account of cross-scale dynamics of change, the interactions between multiple stressors, nor longer term climate change. This policy misfit may be remedied by a move towards adaptive forms of governance, and necessitates an explicit focus on building the adaptive capacity of the poor and most vulnerable in society.

Abstract: This study was conducted to understand how seasonality in drylands influences the space-time dynamics of cattle behavior and mobility among pastoralist managed Zebu cattle. The study relies on the use of handmade collars holding global positioning system (GPS) units to document the spatially and temporally explicit patterns of cattle mobility, field based herd-follows to document cattle behavior, and key informant interviews to document the role of pastoral herding strategies in explaining these patterns. Data were analyzed as a function of seasonality, distance from household, time of day, and land cover zone. During the dry season, there was an unexpectedly high frequency of grazing/walking cattle behavior. This pattern is attributed to [`]tracking' strategies of Maasai pastoralists resulting in movement to niche grazing areas. During the wet season a bimodal distribution of grazing behavior can be attributed to milking strategies. The study concludes that simple, low cost GPS collars are an effective and easily replicable method to help understand the spatial and temporal dynamics of cattle behavior and mobility, and patterns of cattle mobility are related to seasonal constraints. Differences between different cattle behaviors can be partly explained by cultural herding practices of Maasai pastoralists.

Abstract: Environmental impact alters assemblages by increasing species relatedness, thus reducing phylogenetic and functional diversity. We assessed whether different controlled grazing regimes influenced the recovery of plant phylogenetic diversity (Average Taxonomic Distinctness, ATD) and functional diversity based on plant growth habit (GH) and life cycle duration (LCD) [Shannon-Weiner Index (H'), -ln(Simpson's Index, D)] in pastures from previously unmanaged and highly overgrazed conditions. Plant presence/absence data were collected during August 2006 from a high altitude cold salt desert in south-western Utah, where controlled grazing has been maintained for over 70 years to study range restoration. Winter-spring and spring grazed pastures were examined at four grazing levels: ungrazed, light, medium, and heavy, with each level differing in the number of animal use days per hectare relative to available forage biomass. For winter-spring, animal use days were divided equally between the two seasons. Winter-spring grazing promoted recovery of plant phylogenetic and functional diversity compared to spring grazing as reflected by the consistently higher values of ATD, and the stability of species composition within each ecological trait and their similarity to values for ungrazed pastures. Spring grazing was detrimental to recovery efforts and resulted in the reduction of palatable non-grass species, ATD, and functional diversity with increased grazing intensity. Many significant positive correlations between phylogenetic and functional diversity indices existed during spring, but not winter-spring grazing. While H'(GH) was uncorrelated with ATD during winter-spring, it was positively correlated in spring, suggesting species in the plant community (based on growth habit) during spring were randomly assembled without influence from local species interactions, and that different growth habits are conserved within lineages so that communities randomly assembled from more lineages will have a greater diversity of growth habits than communities assembled from fewer lineages. H'(LCD) was negatively correlated with ATD during winter-spring, suggesting local species interactions naturally influence assemblage composition regarding life cycle duration. As such, species within the same lineage likely interact (compete) more for scarce resources because they share similar life cycle durations, thus leading to greater trait variation in communities with fewer lineages than in those with many lineages. Yet, this correlation was positive during spring, suggesting an overriding effect from grazing rather than local species interactions. Hence, sheep grazing at the DER appears to be a season-dependent driver of plant phylogenetic and functional diversity, and the correlations between them. We recommend Average Taxonomic Distinctness and functional diversity based on growth habit and life cycle duration be considered as significant developments in the construction of practical rapid assessment tools for biomonitoring and feedback regarding grazing impacts in similar ecosystems.

Abstract: Abstract 10.1002/ldr.989.abs The relationships between pastoralists, livestock, and the environment in dryland Africa are complex. Over the last half-century dominant narratives have portrayed pastoralists and their livestock as being responsible for �over grazing� and �degradation� without attention to how resource availability and cattle mobility are spatially distributed and temporally variable. The objective of this study is to test hypotheses on the nature, magnitude, and extent of the spatially and temporally explicit interactions between the density and distribution of pastoral cattle and resource availability. The study relies on coupling remotely sensed vegetation indices with cattle Global Positioning Systems (GPS) collar data for a pastoral community in southern Kenya. Data are temporally stratified in order to account for seasonal effects. Across seasons, there is a positive relationship between cattle mobility and resource availability with the trend more pronounced during drier periods, reflecting a strategy of increased resource access. The relationship between cattle density and vegetation reveals a strategy of increased resource utilization during wetter periods. The spatiality of high-density areas differs by season, revealing that cattle intensively utilize different parts of the landscape at different times. Areas closest to the household are consistently impacted by cattle across all seasons. These findings have implications on how the savanna vegetation may be impacted as trends towards sedentarization and reduced pastoral mobility continue. Copyright © 2010 John Wiley & Sons, Ltd.

Abstract: Nomadic livestock husbandry is the main form of land use in Mongolia. Grazing impact on plant productivity has frequently been studied, but effects on dispersal modes are largely unknown. We assessed the relative importance of zoochorous dispersal for several species but focused on the dominant fodder grasses Agropyron cristatum and Stipa krylovii. We searched for seeds in the fur of goats and sheep, but also experimentally attached diaspores and monitored retention. Endozoochory was tested by incubating faecal samples under standardised conditions. Lab experiments on zoochory, anemochory and hydrochory supplemented the field studies. Seed retention in sheep fur was consistently good, and seeds stayed in the fur for hours or even days. Endozoochory proved to be of minor importance, while hydrochory is possible but depends on rarely occurring surface floods. Modelling potential dispersal distances showed that anemochory over larger distances is hardly possible. Thus, long-distance dispersal largely depends on epizoochory, as herds of sheep and goats cover up to 15 km per day and conduct long-range migrations in years of drought. In terms of seed retention potential, goats are relatively poor vectors, which is of concern due to their relative and absolute share of Mongolian livestock herds having dramatically increased in recent years.

Abstract: The objective of this study was to compare the management and economic success of beef production by three types of farm in northwestern Vietnam. The potential of household farms to supply beef for the market and their competition with large farms were examined. The fieldwork was done in 2007 on 73 farms consisting of 58 small mixed farms (small farms), 10 medium mixed farms (medium farms) and 5 specialised large-scale beef farms (large farms) in Son La province. The three types of farm differed in ethnicity (Thai, H'mong, and Kinh), remoteness (lowland, highland), production objectives (subsistence, market output), degree of specialization (mixed farm, specialised beef farm) and integration of production (single farmers, cooperative). Data on biological productivity, inputs and outputs, and the social contribution of cattle production were collected by household and key person interviews, participatory rural appraisal tools and cattle body measurements. Economic values were derived by assessment of market or replacement costs. Quantitative data analysis was done with linear models (PROC GLM) in the SAS software (version 9.1). Lowland small farms had higher costs for cattle production than the highland farms (0.8 Mill. VND head-1 year-1 compared with 0.02 Mill. VND head-1 year-1, respectively). The large farms had high production costs, with an average of 2.5-3.6 Mill. VND head-1 year-1. Cattle brought high benefits of non-cash values to the household farms. The total revenue from cattle was in the range 4.5-11.5 Mill. VND head-1 year-1, which depended on the use of non-market functions of cattle on the household farm. The value of net benefit/kg live weight (LW) of lowland small farms with an average of 39,000 VND/kg LW was significantly higher than that of the medium and small farms in the highlands (26,000 VND/kg LW). However, the small farms kept fewer cattle than the medium farms (average of 2-4 cattle/farm compared with 9 cattle/farm, respectively) because of forage and labour shortages and have no option to further develop cattle production. Keeping larger numbers of cattle based on available natural pasture brought high benefit from stock value as farm liquidity to only the medium farms. This was the most promising type of farm for future development of beef production, given its actual success and the availability of underutilised resources. Large-scale farms suffered high economic losses of 0.3-1.4 Mill. VND cattle-1 year-1, due to the lack of professional management, high feed costs and low animal performance, and showed no potential for developing cattle production.

Abstract: The West African savannas are subject to changes in fire regimes related to land use intensification, which may infer significant biological modifications. We investigated the efficiency of MODIS fire products to account for the variability of fire regimes in relation to changes in land cover and savanna vegetation. The specificity and complementarities of both MODIS active fire (MOD14A2 and MYD14A2) and burnt area (MCD45A1) products were assessed in order to characterize fire regimes and to relate them with land cover. In addition the distribution of plant species among landscape units characterised by specific fire regimes was assessed. The calculation of the mutual information made it possible to set apart species more frequent in landscapes little or not at all subject to fire and species more frequent in burnt areas. The first group is the expression of the nature of the unburnt land-cover units, made up mainly of the agricultural areas dominated by fields and fallows. It consists of more potential threats (weeds, encroachers, invasive species etc.) than the second group, which is more typical of sudanian savannas, where fire provides the long-term stability needed to preserve the ecosystem.

Abstract: In sub-Saharan Africa problems associated with water scarcity are aggravated by increasing demands for food and water, climate change and environmental degradation. Livestock keeping, an important livelihood strategy for smallholder farmers in Africa, is a major consumer of water, and its water consumption is increasing with increasing demands for livestock products. At the same time, current low returns from livestock keeping limit its contribution to livelihoods, threaten environmental health and aggravate local conflicts. The objectives of this review are to: (1) synthesize available knowledge in the various components of the livestock and water sectors in sub-Saharan Africa, (2) analyze livestock-water interactions and (3) identify promising strategies and technological interventions for improved livestock water productivity (LWP) using a framework for mixed crop-livestock systems. The interventions are grouped in three categories related to feed, water, and animal management. Feed related strategies for improving LWP include choosing feed types carefully, improving feed quality, increasing feed water productivity, and implementing grazing management practices. Water management for higher LWP comprises water conservation, watering point management, and integration of livestock production in irrigation schemes. Animal management strategies include improving animal health and careful animal husbandry. Evidence indicates that successful uptake of interventions can be achieved if institutions, policies, and gender are considered. Critical research and development gaps are identified in terms of methodologies for quantifying water productivity at different scales and improving integration between agricultural sectors.

Abstract: Grazing livestock is an important asset to the livelihoods of people in most semi-arid environments, where natural resources cannot be used directly for human consumption. However, overgrazing commonly reduces pasture productivity and therefore threaten people's long-term food security. Ligneous and herbaceous vegetation on grazed and ungrazed sites in the Hajar Mountains, Oman, was studied to evaluate the possibilities of improving pasture management to maintain fodder production. Foliar biomass was 3-6 t dry matter ha-1 on the grazed and ungrazed plateau areas and 41 t dry matter ha-1 in the shallow valleys. Herbaceous yields changed over seasons and contributed <=13% to accessible biomass, stressing the importance of ligneous foliage for livestock nutrition in particular during dry periods. While botanical composition and biomass of the vegetation differed between grazed and ungrazed sites, canopy cover and biomass yields were similar in a 15-year old enclosure and on a naturally ungrazed mountain plateau. Despite the climatic conditions, pastures encompass characteristics of equilibrium systems, where vegetation is strongly influenced by grazing livestock but recovers in its absence. The sustainable use of the natural fodder resources through improved pasture management is therefore a valuable alternative to intense supplement feeding or the introduction of zero-grazing management.

Abstract: This paper takes as its starting point the assertion that current rangeland management in the central Eastern Cape Province (former Ciskei) of South Africa, is characterised primarily by an [`]open-access' approach. Empirical material drawn from three case-study communities in the region is used to examine the main barriers to management of rangeland as a [`]commons'. The general inability to define and enforce rights to particular grazing resources in the face of competing claims from [`]outsiders', as well as inadequate local institutions responsible for rangeland management are highlighted as being of key importance. These are often exacerbated by lack of available grazing land, diffuse user groups and local political and ethnic divisions. Many of these problems have a strong legacy in historical apartheid policies such as forced resettlement and betterment planning. On this basis it is argued that policy should focus on facilitating the emergence of effective, local institutions for rangeland management. Given the limited grazing available to many communities in the region, a critical aspect of this will be finding ways to legitimise current patterns of extensive resource use, which traverse existing [`]community' boundaries. However, this runs counter to recent legislation, which strongly links community management with legal ownership of land within strict boundaries often defined through fencing. Finding ways to overcome this apparent disjuncture between theory and policy will be vital for the effective management of common pool grazing resources in the region.

Abstract: Overgrazing and mismanagement of rangelands, climate change, drought and [`]salinisation' of lands are threatening the sustainability of production systems and the fertility of cropping lands worldwide. This alarming situation drew the attention of policy makers, scientists and technicians and motivated them to develop feasible and sustainable strategies targeting the promotion of livestock sector in arid and semi arid zones, drought mitigation, protection and better use of natural resources (i.e. rangelands and water sources) and combating soil and water salinity. There has been an increasing awareness of the value of shrubs in forage production and for rehabilitation of depleted rangelands. Among the wide range of multipurpose fodder trees and shrubs, oldman saltbush (Atriplex nummularia Lindl.) has received increasing interest as livestock forage and valuable revegetation species on marginal saline lands, especially in arid zones of Australia and in the West Asia and North Africa (WANA) region. Adapted to drought and water and soil salinity, oldman saltbush produces important consumable biomass in areas where other crops cannot grow. To cope with these harsh conditions, this species accumulates high levels of salt and oxalates on its leaves rendering them less palatable and decreasing their nutritive value. Even though, satisfactory performance of small ruminants fed on A. nummularia has been reported in numerous research studies. This paper presents a thorough review of the literature on fodder potential of oldman saltbush and highlights the main constraints and opportunities to make better use of this shrub for feeding sheep and goat under different production systems.

Abstract: In the seasonally dry tropics the productivity of grazing cattle is often constrained by nutrition, particularly during the dry season. An experiment during 2 annual cycles estimated the diet selected by grazing Bos indicus heifers, and their growth and growth responses to a non-protein N supplement. Two drafts (groups) of 2 herds (10 heifers per herd) grazed a pasture consisting of buffel grass (Cenchrus ciliaris) with some legume and edible browse, and herds were offered loose mineral mix (LMM) supplements either without (control) or with urea. Near infrared reflectance spectroscopy measurement of faeces (F.NIRS) was used to estimate each 2 weeks the non-grass and crude protein (CP) concentrations, and DM digestibility (DMD) of the diet selected. Rainfall and diet quality generally followed the seasonal pattern expected for the region and for the seasonally dry tropics. Non-grass (i.e. dicotyledonous species) content averaged 0.13 (S.D. 0.053) of the diet and did not appear to be related to season, but during the first dry season and wet season the urea supplemented heifers selected diets lower (P<0.01 and P<0.05, respectively) in non-grass than the control heifers. Diet quality was generally low during the dry seasons, increased sharply after the seasonal break, and later declined gradually through the wet seasons and wet-dry transition seasons. During the dry seasons average diet CP ranged from 33 to 49 g/kg and diet DMD from 0.480 to 0.507. During the 2 wet seasons CP averaged 94 and 100 g/kg, and the DMD 0.591 and 0.601. The control treatment heifers lost 30 and 32 kg LW during the late dry seasons, and gained 143 and 136 kg during the wet, wet-dry transition and early dry seasons of Drafts 1 and 2, respectively. F.NIRS predicted the daily weight gain (DWG) of the heifers with accuracy useful for management purposes except during the early wet season of Draft 2 when intermittent rains increased diet quality but were insufficient for substantial pasture growth. The urea supplement reduced (P<0.01) heifer LW loss during the dry seasons, but much of this benefit subsequently disappeared due to compensatory growth; net benefit of the urea supplement over the annual cycle was 24 and 14 kg in the 2 drafts. This study demonstrated the capacity of F.NIRS to estimate the diet selected, liveweight change and liveweight responses to a N supplement in grazing cattle.

Abstract: Paradigms about desertification and non-equilibrium dynamics are currently dominating discussions about rangeland and pastoralist systems in semi-arid and arid zones. Climate variability is a major determinant of the dynamics of these systems and the deleterious consequences of this variability are increased for pastoralists for whom traditional mechanisms for coping with drought are increasingly limited. Differential application and interpretation of terminology that relates ecological processes to climatic variability are hampering the unification of research efforts across disciplines. Here we argue that it would be beneficial to resolve these differences by the correct use of terms introduced in the early development of the ecological theory pertaining to these systems.

Abstract: Diagnosis of land condition is a basic prerequisite for finding the degradation of a territory under climatic and human pressures leading to desertification. Ecosystemic approaches, such as the one presented here, address ecosystem maturity or resilience. They are low cost, not very prone to error propagation and well-suited to implementation on remotely sensed time-series data covering large areas. The purposes of this work were to develop a land condition surveillance methodology based on the amount of biomass produced per unit rainfall, and to test it on the Iberian Peninsula. In this article, we propose parallel and complementary synchronic assessment and diachronic monitoring procedures to overcome the paradox of monitoring as a sequence of assessments. This is intrinsically contradictory when dealing with complex landscape mosaics, as relative estimators commonly produced for assessment are often difficult to set in a meaningful time sequence. Our approach is built on monthly time-series of two types of data, a vegetation density estimator (Green Vegetation Fraction-GVF) derived from Global Environmental Monitoring satellite archives, and corresponding interpolated climate fields. Rain Use Efficiency (RUE) is computed on two time scales to generate assessment classes. This enables detrended comparisons across different climate zones and provides automatic detection of reference areas to obtain relative RUE. The monitoring procedure uses raw GVF change rates over time and aridity in a stepwise regression to generate subclasses of discriminated trends for those drivers. The results of assessment and monitoring are then combined to yield the land condition diagnostics through explicit rules that associate their respective categories. The approach was tested in the Iberian Peninsula for the period 1989 to 2000 using monthly GVF images derived from the 1-km MEDOKADS archive based on the NOAA-AVHRR sensors, and a corresponding archive of climate variables. The resulting land condition was validated against independent data from the Natura 2000 network of conservation reserves. In very general terms, land was found to be healthier than expected, with localised spots of ongoing degradation that were associated with current or recent intensive land use. Static or positive vegetation growth rates were detected almost everywhere, including Mediterranean areas that had undergone increased aridification during the study period. Interestingly, degrading or static trends prevailed in degraded or unusually degraded land, whereas trends to improve were most represented in land in good or unusually good condition.

Abstract: The expansion of the artificial water-point network and livestock grazing in arid and semi-arid Australia has significantly increased access to water by water limited herbivores and thus has potential to seriously negatively affect the unique endemic flora and fauna. We examined the effects of the expansion of the water-point network on the arid and semi-arid zone bird community, using data from the Atlas of Australia bird surveys of 1977-1981 and 1996-2001. We examined whether traits of species could be used to uncover the critical ecological processes altered by this land use change. We detected large scale declines in individual species. Species reliant on water for nesting and feeding declined more than other groups in the presence of high water-point density, likely through direct effects of livestock degrading habitat of both natural and artificial water points. The arid zone has no natural hoofed animals and livestock have significant impacts. Species that forage and nest on the ground also showed large declines, likely because of trampling and removal of vegetation by livestock and potentially through the indirect effect of water limited predators, dingos and foxes, expanding their ranges in response to the expanding network of water points in the landscape. This result was also apparent at large spatial scales so that these local-scale responses to water points translate into continental-scale population declines. Using traits of species to understand declines of bird species helped us to uncover which critical changes associated with the expansion of the water-point network most affected the bird community and therefore which species are most at risk.

Abstract: Land cover is a key parameter in geosciences and a linkage between many aspects of the physical and human environments. Savannas belong to the biomes where land cover mapping with remote sensing faces the most difficulties and several studies already addressed the challenging definition of savanna land cover classes. With the aim to standardize ongoing mapping activities, the Land Cover Classification System (LCCS) was initiated in 1993. The classification scheme has been repeatedly utilized for global approaches with coarse resolution remote sensing data, while local or regional applications are still limited in number. This study systematically explored the potential of Terra-ASTER data for LCCS classification in Burkina Faso using 502 field sites. Due to the small-scale landscape heterogeneity, pixel-based classifiers were applied and training data were clustered according to their spectral signatures. Overall classification accuracy decreased from 95.6% over 88.4% to 78.5% when considering the LCCS dichotomous-phase classifiers presence of vegetation, edaphic conditions, and artificiality of cover, respectively. For 16 classes, an overall accuracy of 61.4% was achieved. Altogether, this study is a step towards the systematic combination of standardized LCCS legends with continuously available remote sensing data - one of the core challenges for land cover mapping in the future.

Abstract: Smoke generated by burning of plant materials has widely been recognized as a germination cue for some species from both fire prone and fire-free ecosystems. It is an important factor for the understanding of vegetation dynamics and could have potential use for ecological management and rehabilitation of disturbed areas. Individual species, however, seem to have a specific requirement for the type and dosage of smoke treatments. In the present study, six different concentrations of smoke solution were tested on 13 herbaceous species by soaking the seeds for 24 h. The germination of a forb species, Borreria scabra, was significantly stimulated (p<0.05) by the smoke treatment while that of the annual grass species, Euclasta condylotricha, was significantly inhibited (p<0.05) by 100% smoke solution treatment. Contrary to our expectation that another fire-related cue, heat shock, would break the physical dormancy of the species tested, it was not promotive. For non-dormant seeds of B. scabra and Borreria radiata, high temperatures were lethal while low temperature induced physiological dormancy that was overcome in the former species within 30 days of the germination trial. For some species, responses to smoke did not corroborate with the field-observed response to fire, making ecological interpretation challenging. For responsive species, the smoke treatment could be a simple approach for promoting their re-establishment in areas where it is needed. More investigations are needed to assess the spread of response to smoke.

Abstract: This paper examines the effects of rangeland enclosure on herders' livelihoods and property rights. The analysis is based on the household survey and focus group discussions among pastoral and agropastoral households (from three administrative districts in eastern Ethiopia) who have practiced enclosure and who have been affected by practices of others. Such an examination helps anticipate whether enclosure practice assists in attaining income security and ensuring household welfare by supporting livestock development. Results have shown that expansion of enclosure leads to the emergence of incompatible demands (conflict of interest) over the resource and unstable property rights to the grazing commons. Though private benefits from enclosure produce an incentive for households to practice it, its expansion does not generally increase the welfare of (agro-) pastoral community in the longer-term. Hence, land use policies that favor private use of the rangeland, using land enclosure as an entry point, can potentially harm pastoral livelihoods rather than supporting sustainable pastoral development.

Abstract: Sustainable natural resource management requires inputs from both the natural and the social sciences. Since natural and social systems are inter-related and inter-dependent, it is essential that these data can be integrated within a given analysis, which requires that they are spatially compatible. However, existing environmental and socio-economic monitoring networks tend to observe, collect and report socio-economic and biophysical data separately; with the result that much of these data are spatially incompatible, adding to the complexity of objective and consistent resource management. We present an approach for overcoming spatial incompatibilities between socio-economic and biophysical data; based on a meta-modelling approach using Geographical Information Systems and an application of a water-use simulation model. The method is developed and applied to the irrigation agriculture sector in the Inkomati Water Management Area in South Africa. Agricultural census data, which are measured on a magisterial district scale, are integrated with geo-referenced land-cover data, which are independent of political boundaries. This allows us to increase the resolution at which data on the economic value derived from irrigation water are presented, from coarse magisterial district scale to a finer [`]meso-zone' scale, enabling more efficient allocations of irrigation water within magisterial districts.

Abstract: Surface application of biosolids increases soil moisture and fertility in semiarid rangelands. Then, biosolids may help in rehabilitation of degraded semiarid rangelands. The study evaluated blue grama grass (Bouteloua gracilis) establishment with biosolids under greenhouse conditions. Six biosolids rates (0, 10, 20, 30, 40 and 50 dry Mg ha-1) and two application methods (surface and incorporated) were evaluated. Fifteen seeds per pot were seeded and irrigation was below normal precipitation for the region. Measured variables were soil fertility and moisture, seedling emergence and survival, shoot length and biomass, root length and biomass. Data were analyzed with a factorial arrangement in a completely randomized design and logistic models. Soil fertility and moisture were higher with biosolids. Plant emergence and survival decreased with increasing biosolids rates. Biosolids did not affect plant growth at 30 days, although shoot length and aboveground biomass at 120 days increased at biosolids rates from 10 to 30 Mg ha-1 at both methods. Biosolids at 10 Mg ha-1 may benefit establishment of surviving blue grama plants without restricting emergence and survival. The potential benefits and increasing generation of biosolids indicate that biosolids application to degraded arid and semiarid rangelands could be an alternative for biosolids disposal.

Abstract: Although alpine pans have been reported from a variety of mountain regions, these have received limited research attention and are thus amongst the least known of [`]closed basins'. This study investigates macro- and fine-scale morphological attributes and the process dynamics of alpine turf exfoliation pans in the high Drakensberg of Lesotho, southern Africa. Climate data (temperature, precipitation and wind) are used to better ascertain climate-surface process linkages and how these may be associated with the observed morphological phenomena. Thirty pans were assessed for both macro- and fine-scale aspect-controlled morphological attributes. During 2005, Tinytag(TM) temperature loggers recorded ground temperatures on various pan riser aspects to establish the potential for cryogenic activity. Similarly, wind speed and direction data from 2001 were used to identify the potential role of wind as an erosion and transportation mechanism. The number and total weight of detached turf clumps accumulated at the base of various pan riser aspects were determined in July 1999, September 2001 and September 2004. It is suggested that the pans originated through initial turf disruption by animal trampling and turf burning, followed by the cryogenic up-heave of sediments. The pans typically elongate towards the southeast as they enlarge, demonstrate most active erosion on eastern and southeastern riser aspects, and host seasonal micro-echo and micro-climbing dunes along such riser aspects. It is concluded that an annual cyclic (seasonal) pattern of contemporary climate-driven geomorphic processes, dominated by strong northwesterly winds, control the fine-scale morphological evolution of alpine turf exfoliation pans in the Lesotho highlands.

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Abstract: This work is devoted to a presentation of the ECOCLIMAP-II database for Western Africa, which is an upgrade for this region of the former initiative, ECOCLIMAP-I, implemented at global scale. ECOCLIMAP-II is a dual database at 1-km resolution that comprises an ecosystem classification and a coherent set of land surface parameters. This new physiographic information (e.g. leaf area index, fractional vegetation cover, albedo and land cover classification), was especially developed in the framework of the African Monsoon Multidisciplinary Analysis (AMMA) programme in order to support the modelling of land-atmosphere interactions, which stresses the importance of the present study. Criteria for coherence between prevalent land cover classifications and the analysis of time series of the satellite leaf area index (LAI) between 2000 and 2007 constitute the analysis tools for setting up ECOCLIMAP-II. The LAI and inferred fraction of vegetation cover are spatially distributed per land cover unit. The fraction of vegetation cover is handled to split the land surface albedo into vegetation and bare soil albedo components, as is required for a large number of applications. The new ECOCLIMAP-II land cover product is improved with regard to the spatial coherence compared to former version. The reliability of the physiographic details is also confirmed through verification with land cover products at higher resolution.

Abstract: In this study, two small experimental catchments were selected in semi-arid grassland in Mongolia. The Kherlen-bayan Ulaan (KBU) catchment has been subjected to intensive grazing as a wintering shelter for domestic livestock animals, and the number of livestock animals in the Baganuur (BGN) catchment has been increasing over the last few decades. The rates and patterns of soil erosion within the catchments were estimated based on cesium-137 (137Cs) and lead-210 (210Pbex) inventories in bulk soil core samples. The medium-term (~ 40 years) soil erosion rates based on the 137Cs measurements indicated that annual soil loss from the KBU catchment was approximately three times greater than that from the BGN catchment. The 137Cs-derived rates and patterns of soil erosion indicated that soil in the KBU catchment was susceptible to surface erosion, with facilitated transport of eroded sediment to the catchment outlet. The 210Pbex-derived soil erosion rates were generally greater than those derived from 137Cs in both catchments. If we assume that the soil erosion rate has been increasing with increasing domestic livestock numbers, the most plausible explanation is that the 210Pbex-derived estimates represent recent increases in soil erosion. Furthermore, the 210Pbex/137Cs inventory ratio showed a tendency to increase with downslope distance on the eroded hillslope in the BGN catchment. Assuming that the increase in inventory ratio is a result of constant fallout input of 210Pbex on the eroded sediment during its transportation along the hillslope, the 210Pbex inventory may not be suitable to estimate soil erosion rates at sites where downslope movement of sediment is slow. Further discussion regarding interpretation of 210Pbex-derived soil loss is required, and the applicability of the 210Pbex technique on semi-arid hillslopes remains to be determined.

Abstract: This paper presents the development and validation results of a weighted small-world network model designed to simulate fire patterns in real heterogeneous landscapes. Fire spread is simulated on a gridded landscape, a mosaic in which each cell represents an area of the land surface. In this model, the interaction between burning and non-burning cells (here, due to flame radiation) may extend well beyond nearest neighbors, and depends on local conditions of wind, topography, and vegetation. An approach based on the coupling of the solid flame model with the Monte Carlo method is used to predict the radiative heat flux from the flame generated by the burning of each combustible cell to its neighbors. The weighting procedure takes into account latency (a combustible cell will only ignite when it has accumulated enough energy along time) and flaming persistence of burning cells. The model is applied to very different fire scenarios: a historical Mediterranean fire that occurred in southeastern France in 2005 and experimental fires conducted in arid savanna fuels in South Africa in 1992. Model results are found to be in agreement with real fire patterns, in terms both of rate of spread, and of the area and shape of the burn. This work also shows that the fractal properties of fire patterns predicted by the model are similar to those observed from satellite images of three other Mediterranean fire scars.

Abstract: Using the results from a long-term grazing trial in the Dry Highland Sourveld of the KwaZulu-Natal province, we prepared a water use efficiency value (the ratio of the increment in annual biomass to total annual evapotranspiration) for this rangeland type. Using seasonal biomass measurements recorded between March 2000 and March 2007, we developed a model for predicting the increment in annual biomass using a regression relationship between fPAR (fraction of photosynthetically active radiation intercepted by the vegetation canopy) and measured standing biomass. This regression model was used to estimate the growth rates from fPAR for the period 2001�2006. During the period 2004�2007, when complete meteorological records were available, we calculated reference or potential evapotranspiration (ET0) using the Penman-Monteith equation. To approximate actual evapotranspiration (ETa), we used the MODIS leaf area index to approximate canopy conductance component (Gs) of the Penman-Monteith equation. Using the adjusted fPAR curves as a surrogate for plant growth, and ETa, we calculated a water use efficiency value for these grasslands of 7.5 ± 0.48 kg DM mm-1 ha-1 y-1. This value relates well to other published water use efficiencies for natural rangeland.

Abstract: Fire is important for the maintenance and conservation of African savanna ecosystems, and prescribed fire is used in the Sudanian savanna-woodlands of West Africa as a forest management tool. Yet, the effects of fire on savanna ecosystems and especially on plant species is very much dependent on the nature of the fire regime. We assessed the effects of season of burning on herbaceous species dynamics and phytomass for four years (2006�2009). Neither fire season nor the interaction between year and fire season affected species richness, diversity, phytomass and dominant species (Andropogon chinensis (Nees) Merr.) abundance. There was, however, an interannual variation (p < 0.05) on all herbaceous species attributes except abundance of A. chinensis. This could be related to interannual variation in amount and frequency of rainfall. We also examined the whole species community using canonical correspondence analysis on the species data matrix and the fire treatment data matrix. There was no clear indication of some species showing affinity to a particular season of burning, although certain tendencies were observed. Overall, in the short-term (four years), there is no evidence of burning season affecting herbaceous species community in this ecosystem.

Abstract: The present paper records the results of a case study on the impact of an extensive grassland fire on the physical and optical properties of aerosols at a semi-arid station in southern India for the first time from ground based measurements using a MICROTOPS-II sunphotometer, an aethalometer and a quartz crystal microbalance impactor (QCM). Observations revealed a substantial increase in aerosol optical depth (AOD) at all wavelengths during burning days compared to normal days. High AOD values observed at shorter wavelengths suggest the dominance of accumulation mode particle loading over the study area. Daily mean aerosol size spectra shows, most of the time, power-law distribution. To characterize AOD, the Angstrom parameters (i.e., [alpha] and [beta]) were used. Wavelength exponent (1.38) and turbidity coefficient (0.21) are high during burning days compared to normal days, thereby suggesting an increase in accumulation mode particle loading. Aerosol size distribution suggested dominance of accumulation mode particle loading during burning days compared to normal days. A significant positive correlation was observed between AOD at 500 nm and water vapour and negative correlation between AOD at 500 nm and wind speed for burning and non-burning days. Diurnal variations of black carbon (BC) aerosol mass concentrations increased by a factor of ~ 2 in the morning and afternoon hours during burning period compared to normal days.

Abstract: Like other African countries, Madagascar is concerned by vegetation cover degradation especially in savanna ecosystems. In this article, we describe an approach to quantify and localise savanna vegetation cover degradation. To this end, we analyse using STL decomposition method the trends measured between 2000 and 2007 of two phenological indicators which are derived from NDVI MODIS time series and characterizing vegetation activity during the growing season. Three types of trend were observed - null, positive or negative - over the study period with which we can associate a state of vegetation cover degradation. Future work will provide validation of this result. Next a comparison between the spatial variations of vegetation cover degradation and fire pressure for the same period should improve knowledge on the effect of fire on savanna vegetation activity. This information will be useful for local managers in order to implement savanna management strategies.

Abstract: The water-wind crisscross region of the Loess Plateau in China is comprised of 17.8 million hectares of highly erodible soil under limited annual rainfall. This requires a sustainable water balance for the restoration of dryland ecosystems to reduce and manage soil erosion. In this region, alfalfa has been one of the main legumes grown to minimize soil erosion. However, alfalfa yields were significantly lower in years of reduced rainfall suggesting that high water use and deep rooting alfalfa make it an unsustainable crop due to the long-term decline in soil water storage and productivity. Our objectives in this study were to evaluate the soil water balance of Loess Plateau soils during vegetative restoration and to evaluate practices that prevent soil desiccation and promote ecosystem restoration and sustainability. Field observations of soil moisture recovery and soil erosion were carried out for five years after alfalfa was replaced with different crops and with bare soil. Soil water content changes in cropland, rangeland, and bare soil were tracked over several years, using a water balance approach. Results indicate that growing forages significantly reduced runoff and sediment transport. A forage-food-crop rotation is a better choice than other cropping systems for achieving sustainable productivity and preventing soil erosion and desiccation. However, economic considerations have prevented its widespread adoption by local farmers. Alternatively, this study recommends consideration of grassland crops or forest ecosystems to provide a sustainable water balance in the Loess Plateau of China.

Abstract: Abstract Atmospheric CO2 has more than doubled since the last glacial maximum (LGM) and could double again within this century, largely due to anthropogenic activity. It has been suggested that low [CO2] contributed to reduced tree cover in savanna and grassland biomes at LGM, and that increasing [CO2] over the last century promoted increases in woody plants in these ecosystems over the past few decades. Despite the implications of this idea for understanding global carbon cycle dynamics and key global role of the savanna biome, there are still very few experimental studies quantifying the effects of CO2 on tree growth and demography in savannas and grasslands. In this paper we present photosynthetic, growth and carbon allocation responses of African savanna trees (Acacia karroo and Acacia nilotica) and a C4 grass, Themeda triandra, exposed to a gradient of CO2 concentrations from 180 (typical of LGM) to 1000 µmol mol�1 in open-top chambers in a glasshouse as a first empirical test of this idea. Photosynthesis, total stem length, total stem diameter, shoot dry weight and root dry weight of the acacias increased significantly across the CO2 gradient, saturating at higher CO2 concentrations. After clipping to simulate fire, plants showed an even greater response in total stem length, total stem diameter and shoot dry weight, signalling the importance of re-sprouting following disturbances such as fire or herbivory in savanna systems. Root starch (per unit root mass and total root starch per plant) increased steeply along the CO2 gradient, explaining the re-sprouting response. In contrast to the strong response of tree seedlings to the CO2 gradient, grass productivity showed little variation, even at low CO2 concentrations. These results suggest that CO2 has significant direct effects on tree recruitment in grassy ecosystems, influencing the ability of trees to recover from fire damage and herbivory. Fire and herbivore regimes that were effective in controlling tree increases in grassy ecosystems could thus be much less effective in a CO2-rich world, but field-based tests are needed to confirm this suggestion.

Abstract: A significant challenge in ecological studies has been defining scales of observation that correspond to the relevant ecological scales for organisms or processes of interest. Remote sensing has become commonplace in ecological studies and management, but the default resolution of imagery often used in studies is an arbitrary scale of observation. Segmentation of images into objects has been proposed as an alternative method for scaling remotely-sensed data into units having ecological meaning. However, to date, the selection of image object sets to represent landscape patterns has been largely subjective. Changes in observation scale affect the variance and spatial dependence of measured variables, and may be useful in determining which levels of image segmentation are most appropriate for a given purpose. We used observations of percent bare-ground cover from 346 field sites in a semi-arid shrub-steppe ecosystem of southern Idaho to look at the changes in spatial dependence of regression predictions and residuals for 10 different levels of image segmentation. We found that the segmentation level whose regression predictions had spatial dependence that most closely matched the spatial dependence of the field samples also had the strongest predicted-to-observed correlations. This suggested that for percent bare-ground cover in our study area an appropriate scale could be defined. With the incorporation of a geostatistical interpolator to predict the value of regression residuals at unsampled locations, however, we achieved consistently strong correlations across many segmentation levels. This suggests that if spatial dependence in percent bare ground is accounted for, a range of appropriate scales could be defined. Because the best analysis scale may vary for different ecosystem attributes and many inquiries consider more than one attribute, methods that can perform well across a range of scales and perhaps not at a single, ideal scale are important. More work is needed to develop methods that consider a wider range of ways to segment images into different scales and select sets of scales that perform best for answering specific management questions. The robustness of ecological landscape analyses will increase as methods are devised that remove the subjectivity with which observational scales are defined and selected.

Abstract: The forest-steppe ecotone in NW Patagonia is a semiarid ecosystem affected by natural and anthropogenic fires, and overgrazing by sheep. Following a wild fire in the driest portion of this ecotone, a 3-year study was conducted to assess the impacts of a single application of inorganic and organic fertilizers on soil and vegetation recovery. Organic fertilizers were composts derived from biosolids and municipal solid wastes. Six treatments were evaluated: screened and unscreened biosolids compost and municipal solid wastes compost (40 Mg ha(-1)), inorganic fertilizer (100 kg N and 35 kg P ha(-1)), and no application. Soils were chemically characterized, and soil microbial activity was assessed as potential respiration and N-mineralization. Vegetation responses included plant cover, composition, phytomass, and N resorption prior to abscission, and leaf litter quality of the dominant species. Organic fertilizers increased soil organic matter, nutrients and microbial activity. Plant cover and aboveground phytomass, dominated by the native perennial tussock grass Poa ligularis, showed a higher increase with inorganic than with organic fertilization. While vegetation responded more to inorganic fertilizer, due to its higher initial pulse of available N, organic fertilizers had a positive impact on soil chemical and biological properties.

Abstract: This paper evaluates the history of fire management in the Bontebok National Park (3435 ha) over a period of almost four decades. A GIS database was compiled of all fires between 1972 and 2009 and the fire regime was analysed in terms of the frequency, season, size and cause of fires. Since the early 1970s, short interval burning was implemented to promote grazing for bontebok, but from 2004 the fire interval was lengthened to favour plant species diversity, an increasingly urgent conservation priority for the park. In total, 43 fires were recorded, ranging in size from 9 to 1007 ha, collectively spanning 14 013 ha. The majority of fires were large (100-500 ha), with fires of >100 ha accounting for 96% of the area burnt. The overall mean fire return period (FRP) for the park was 7.2 years, which is short judged by fynbos standards. FRPs under the old and new management regimes were 6.7 and 10.9 years respectively. Under the old regime, FRPs in renosterveld and fynbos were 5.8 and 8.0 years respectively. Large parts of the park repeatedly experienced fires at immature vegetation ages resulting in the elimination of slow-maturing seed-regenerating plant species such as Protea repens. Post-fire age distribution was highly skewed towards young vegetation, with 75% of fire-prone vegetation burning at post-fire ages of <=7 years, and <10% of fire-prone vegetation surviving beyond 10 years of age. Prescribed and accidental fires respectively accounted for 70% and 30% of the total area burnt. Prescribed burning was mostly done in March-April, and only 8% of the total area burnt, burnt outside of the ecologically acceptable fire season. This study identified areas which have been subject to ecologically appropriate and inappropriate fire return intervals, providing a basis for informed future management and research.

Abstract: In this study, characteristics of vegetation and soil properties under continued grazing and exclusion of livestock for 6 and 12 years were examined in a degraded Stipa tenacissima steppe in South Tunisia. Exclosures enhance the total plant cover, the dry matter yield, the number of species per unit area and the Shannon-Wiener diversity. Some palatable species were frequently found inside the protected site. In the continually grazed site, these species are being replaced by less desirable species. Contents of soil organic matter, total nitrogen, Ca2+ and K+ in soils, as well as, water infiltration rate and basal soil respiration showed an increasing trend as time of grazing exclusion increased, from minimum values in the continually grazed area (Gr) to the maximum levels in 12 years protected area (12ex), while there was an opposite trend for Na+ concentration, EC, pH and soil hydrophobicity values. The results suggested that excluding grazing livestock on the arid degraded steppes has a great potential to restore vegetation and soil. Therefore, it must be encouraged as an alternative to stop further degradation and to combat desertification in arid and semi arid ecosystems.

Abstract: In spite of predictions of communal rangeland collapse due to continuous grazing and increased livestock populations, this grazing system remains prevalent in communal areas, suggesting animals utilise heterogeneity found in these areas. A study was conducted to compare biomass and herbaceous species composition in patches frequently grazed by cattle to randomly selected control sites in three communal areas located in Lesotho Highland Basalt Grassland (Magwiji), Bhisho Thornveld (Mnyameni) and Tsomo Grassland (Cala). The relationship of vegetation parameters in frequently selected patches to the corresponding soil properties, topography and human impact was also examined. Biomass of frequently selected patches was significantly (p < 0.05) higher in the dry season (June) at Magwiji (528 kg ha-1) than in less frequently selected patches (130 kg ha-1). There was an association between sites selected in winter and soil organic carbon, and these sites were dominated by Cynodon dactylon and Pennisetum clandestinum. The floristic patterns observed in Magwiji were associated with soil organic carbon content. Low-lying swampy patches had high soil pH in Cala, while mountain top soils in Magwiji had low electrical conductivity and these areas selected in winter were associated with grass species such as Eragrostis superba and Heteropogon contortus.

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Abstract: This study investigates the extent to which seed production in Schinus molle is dependent upon pollinators and outcrossing with the objective of understanding whether pollination and seed set could be a barrier to the spread of S. molle in arid savannas of South Africa. Pollination experiments demonstrated that seed set was greater in female flowers exposed to natural pollinators than in those from which pollinators were excluded. However, the fact that a few seeds were also found in treatments protected from pollinators and not treated with pollen may indicate that some S. molle flowers might be bisexual and capable of self-pollination. The results suggest that S. molle fruit set is mainly affected by insect pollination, but there is also the possibility of self-pollination and apomixis.

Abstract: Livestock production contributes to the livelihoods of the Ethiopian people; however, the productivity of the livestock subsector in the highlands is low due to malnutrition. Therefore, this study assessed the botanical composition, dry matter (DM) yield, chemical composition and in vitro dry matter digestibility (IVDMD) of the grassland. The study was conducted in a 3 in vitro dry matter digestibility (IVDMD) of the grassland. The study was conducted in a 3 in vitro dry matter digestibility (IVDMD) of the grassland. The study was conducted in a 3 � 4 factorial experiment arranged in a randomised complete block design with three replications. The treatments were three harvesting times (60, 90 and 120 d after regrowth) and four nitrogen (N) fertiliser levels (0, 50, 100 and 150 kg ha-1). Harvesting at 90 d and application of 100 and 150 kg ha-1 N fertiliser had a higher (P < 0.05) total DM yield of the grassland. Crude protein, neutral detergent fibre, acid detergent fibre, cellulose, hemicellulose, phosphorus and IVDMD were significantly (P < 0.05) affected by the stage of harvesting. However, N fertiliser had no significant effect on chemical composition and IVDMD of the grassland. The results confirmed that the grassland can be categorised as medium- to high-quality herbage if harvested at 90 d after regrowth. Further studies on animal performance and feed intake to develop grassland-based diets are suggested for smallholder livestock producers in the highlands of Ethiopia.

Abstract: Soil communities can have profound effects on invasions of ecosystems by exotic plant species. We propose that there are three main pathways by which this can happen. First, plant-soil feedback interactions in the invaded range are neutral to positive, whereas native plants predominantly suffer from negative soil feedback effects. Second, exotic plants can manipulate local soil biota by enhancing pathogen levels or disrupting communities of root symbionts, while suffering less from this than native plants. Third, exotic plants produce allelochemicals toxic to native plants that cannot be detoxified by local soil communities, or that become more toxic following microbial conversion. We discuss the need for integrating these three pathways in order to further understand how soil communities influence exotic plant invasions.

Abstract: Desertification, the conversion of arid grasslands to shrublands due to overgrazing and drought, is occurring on over a quarter of the land on earth. Conceptual models of desertification predict desertified shrublands are in a stable state, and grass recovery is unlikely. These models hypothesize that as grass is lost, feedback loops involving low soil nutrients or insufficient water infiltration rates prevent the return of perennial grasses to desertified sites. However, these models cannot account for recent reports of reversals of desertification following long-term livestock removal. Here, we analyzed soil nutrients and water infiltration at a desertified site where native perennial grasses are recovering inside a 49-year livestock exclosure. We found higher water infiltration and soil nutrients inside the exclosure. We postulate that in the absence of livestock there is a slow release from compaction that, over decades, results in an increase in water infiltration and a concomitant decrease in erosion, which promotes nutrient accumulation in the soil. Our data support key desertification model assumptions: increased nutrients and infiltration are associated with reversal of desertification. This suggests that given sufficient time and removal of livestock, soil properties at some desertified sites can improve sufficiently to support the re-establishment of perennial grasses.

Abstract: Predicting the effect of different management strategies on range condition is a challenge for farmers in highly variable environments. A model that explains how the relations between rainfall, livestock and vegetation composition vary over time and interact is needed. Rangeland ecosystems have a hierarchical structure that can be described in terms of vegetation composition, stocking rate and rainfall at the ecosystem level, and the performance of individual animals and plants at the lower level. In this paper, we present mathematical models that incorporate ideas from complex systems theory to integrate several strands of rangeland theory in a hierarchical framework. Compared with observed data from South Africa, the model successfully predicted the relationship between rainfall, vegetation composition and animal numbers over 30 years. Extending model runs over 100 years suggested that initial starting conditions can have a major effect on rangeland dynamics (divergence), and that hysteresis is more likely during a series of low rainfall years. Our model suggests that applying an upper threshold to animal numbers may help to conserve the biodiversity and resilience of grazing systems, whilst maintaining farmers� ability to respond to changing environmental conditions, a management option here termed controlled disequilibrium.

Abstract: Sustainable rangeland management is an important issue not only in semi-arid areas but also in sub-tropical regions. For optimal utilization and protection of natural resources, spatial information on the current state and grazing intensity are required. In this paper the integration possibilities of remote sensing derived information for an optimized rangeland management in the sub-tropical province of Corrientes, Argentina, are investigated. Multi-temporal Landsat imagery is utilized in order to classify land cover types and grazing intensity. The map legend was produced according to the United Nations/Food and Agriculture Organization Land Cover Classification System with special emphasis on separating different rangeland types and management practices. Grazing intensity categories were defined based on percentage of bare soil, sward height and standing dead material. Following a correlation analysis between spectral information and historical ground truth data, above ground biomass was estimated for rangelands. The relationship between total above ground biomass and NDVI (r2 = 0.5, P = 0.05) was significant but weak. However, rangeland biomass estimation excluding the complex influence of non-edible vegetation remained a challenge. Accurate stocking rates calculated for the Empedrado Department indicated that current rates were 16% higher than those calculated only on an area basis.

Abstract: Patch-mosaic burning (PMB) is commonly advocated to create a mosaic of fire regimes that is believed to be more beneficial for maintaining biodiversity than the relatively homogeneous environment produced by block burning. This premise was examined for the 23 651 ha Mkuzi Game Reserve, in which all fires have been mapped for a period of block burning (1966�1984) and for a period of PMB (1985�1999), using a geographic information system. Patch-mosaic burning met with the expectation of creating a more heterogeneous fire regime as evidenced by a four-fold increase in average fire frequency, a greater area of reserve burnt per annum, an increase in the perimeter-to-area ratio of individual burns, and a greater proportion of fires occurring throughout the dry season as opposed to being concentrated toward the end of the dry season. In contradiction of expectation, size of individual burns did not differ between strategies, both periods were characterised by intense fires, and natural barriers to fire did not increase in importance under PMB. There was a reduced importance of arson fires and a markedly increased proportion of prescribed burns under PMB. Patch-mosaic burning has met in part its objective of creating a more heterogeneous fire regime.

Abstract: The direct short-term impact of three rates of stocking (4, 8 and 16 small-stock units [SSU] ha-1) was quantified in terms of soil characteristics of arid Nama Karoo vegetation (subshrub/grass). Mature Merino wethers grazed in the experimental plots throughout May in 1995 and 1996 (the plots were not subjected to grazing at any other time). Stocking rate proved inversely related to initial infiltration rate. Light trampling (4 SSU ha-1) loosened the topsoil sufficiently to increase the initial infiltration rate: infiltration capacity of soil in fields stocked at 4 SSU ha-1 and 16 SSU ha-1 was 17% higher and 14% lower respectively than that of soil of ungrazed rangeland over the two grazing periods. Increased soil compaction and greater bulk density due to higher stocking rates significant decreased the infiltration rate. Compared to ungrazed rangeland stocking rates of 4, 8 and 16 SSU ha-1 over the two grazing periods increased bulk density respectively by 2.73%, 6.67% and 8.945% and compaction by 10.90%, 16.78% and 20.90%. No grazing also increased bulk density and soil compaction and decreased infiltration rate. Light stocking (4 SSU ha-1) influenced all soil parameters most favourably. From a hydrologic point of view, grazing levels and rotation schemes need to be tailored for sustainable utilization of arid subshrub/grass vegetation by livestock.

Abstract: The compilation of published results on the geography of the Monte Desert biome of Argentina that we present here offers a review of its boundaries and ecotones, and of its biophysical and socio-economic characteristics. In relation to socio-ecological issues, the focus is on a case study in the province of Mendoza. An analysis is presented about the ecological-economic issues and the sustainable investment policies in rangelands of the Patagonian Monte. In addition, this biome is compared with other South American arid biomes and their North American counterparts. We identified some gaps in the current knowledge, especially at a mesoscale level, where studies on Monte borders are deemed necessary as well as explicit boundary criteria for ecosystem differentiation. Also the ecological-economic relations and feedbacks between livestock herbivory, soil erosion and market behaviour should be considered within the framework of wider socio-ecological research.

Abstract: The relationships between the spatial distribution of gully erosion and topographic thresholds in the form of slope angle, position and configuration, as well as land use change in the form of abandoned lands were examined in several affected catchments of the Eastern Cape Province, South Africa. Land use and permanent gullies were mapped, digitized from orthophoto maps in Arc/info 3.5.2 GIS and converted to shapefiles using ArcView 3.2 GIS. Relationships between the mapped phenomena and topographic variables were sought using a Digital Elevation Model (DEM) in Idrisi Kilimanjaro GIS. A comparison between areas with a high potential for gullying and actual gully erosion was made using the Stream Power Index (SPI) as a surrogate for critical flow shear stress. Field surveys were also conducted to assess the present condition of the gullied sites as well as to validate DEM derivations. Seventy five percent of the gullied area was noted to lie on abandoned lands. A predominance of gullying in concave bottom lands was also identified. The SPI values highlighted a distinct preferential topographic zone for gully location. A conceptual model depicting the interaction between land use and topographic parameters to induce gully erosion was developed. This should assist local authorities to develop a policy regarding management of abandoned lands.

Abstract: Data from the NASA'S MODIS (Aqua and Terra) and EUMETSAT'S MSG-SEVIRI satellite sensors is analysed to characterise the geographic and temporal (including diurnal) evolution of the July 2007 fire disaster in the Kingdom of Swaziland using a geographic information system (GIS). Significant fire activity was observed during a three-day period beginning on the 27th July 2007. A total of 1358 and 4365 active fire hotpots were detected by MODIS and MSG-SEVIRI, respectively, mainly concentrated in the Highveld (70.91% for MODIS, 89.89% for MSG) and Middleveld (11.27% for MODIS, 5.23% for MSG) with MSG/MODIS active fire count ratio ranging from a high of 3.69 in the Highveld to a low of 0.06 in the Lubombo Plateau. The results indicate complex differences in spatial fire distribution, behaviour and risk within the country and the effect of sensor differences. A pronounced fire diurnal cycle with a broad afternoon peak centred on 14:00 local time is observed, in general agreement with observations from the region. Despite their limitations, the study demonstrates the importance and usefulness of remotely sensed data and GIS technology for fire disaster and risk assessment for a developing country, where fire monitoring resources are scarce.

Abstract:

Abstract: Literature shows that at a global scale, fire activity increased from the Last Glacial Maximum to the present. There is incremental evidence indicating that climate defines the regional boundary conditions for fire. Human influence on ignitions depends on climate and has, since prehistoric times, resulted in significant changes on vegetation and soil, some of which require greater attention in the light of anthropogenic climate change. Climatic conditions have been used to identify regions where fire patterns are (i) human controlled, (ii) constrained by fuel and (iii) limited by rainfall seasonality. At regional and local scales, the fire-climate relationship is distorted by the interactions of fire, vegetation, and land use, and this, combined with annual to decadal climatic variability since late Holocene, results in high spatial and temporal variations in fire regimes.

Abstract: Summary Post-1994 land reform policies have had limited effects on land use in the communities surrounding Dwesa-Cwebe Nature Reserves in South Africa's Transkei region. Likewise, prior state interventions have largely been resisted and ignored. Instead, community-driven processes, influenced by the regional political economy, have shaped diverse patterns of changes in land use. These relate to the diverse livelihood styles in the area: different patterns of education, labor migration, and consumption have affected local use of land and forest products. Activities planned under land reform, however, may threaten local control of land tenure and use.

Abstract: Sustainability impact assessment tools aim at optimising the development of policy measures. Here, we present an approach to designing policies for multifunctional land use with application to Europe and its regions. After the 35 environmental, social and economic impact issues of the European Impact Assessment Guidelines were reviewed on the basis of spatiotemporal indicators at both the top-down Europe-wide and bottom-up intra-regional resolution level, cluster analysis identified classes with specific sustainability characteristics and thus regions most likely facing similar sustainability problems. Sensitive region types such as post-industrial zones, mountains, coasts and islands were analysed separately. The results of the cluster analysis were tested against evidence-based information such as UNEP priorities and regional stakeholder evidence. Stakeholder evidence was specifically explored for the land use policy [`]bioenergy promotion' in Lusatia, Germany. We concluded that these top-down and bottom-up spatiotemporal data classifications with cluster analysis represent useful ex-ante impact assessment tools and need to be supplemented by participatory assessments. This procedure with top-down and bottom-up data analysis, and also participatory evidence, provide a valuable three-step sustainability impact assessment approach in policy making.

Abstract: In this paper, we re-interpret three cases of research previously carried out in Mali, Niger and South Africa in light of the recent debate about formalisation of land rights that has emerged since the publication of Hernando de Soto's [`]Mystery of Capital'. The Malian case shows that lack of broad access to formalisation processes in high-pressure areas may play into the hands of those with power, information, and resources. The case also demonstrates that timing of formalisation efforts in urban areas characterised by rapid expansion is crucial in terms of distributive outcomes. The Nigerien case demonstrates how impending formalisation led to a scramble for land and increased conflicts in a context of institutional competition and limited administrative capacity. The South African case shows that the very process of surveying and registering rights may also change the rights themselves. Formalisation procedures may also amplify the tension between individual and communal rights, and boost privatisation.

Abstract: The potential and regeneration capacity of soil seed banks in three eastern Ethiopian rangeland ecosystems (Asbuli grassland or arid grassland, Aydora open savanna or arid bush/grassland and Hurso closed savanna or arid bush land) were determined over a degradation gradient. Soil samples from 0.09 m2 blocks (100 mm deep) were spread evenly in plastic containers in the greenhouse and studied over a 1-year period. The aboveground species composition was also compared. Sampling was from rangelands in excellent, good, moderate and poor conditions for each ecosystem. A total of 122 plant species were identified in the soil seed banks, with 32% in the Asbuli grassland, 35% in the Aydora open savanna and 33% in the Hurso closed savanna. Seedlings emerging from soil samples were in the order of decreasing number, grasses, forbs, woody plants, weeds and legumes. Seedling density decreased (P < 0.05) in the soil seed bank with rangeland degradation in all ecosystems. Grass species richness was poorer in the degraded Asbuli grassland ecosystems, but increased in the Aydora open savanna and Hurso closed savanna. The grass species Tragus berteronianus and woody plant Crotolaria albicaulis dominated the botanical composition of the seed bank for all ecosystems with rangeland degradation. Eragrostis cilianensis and Eriochloa nubica were the dominant grass species in the soil seed bank of all ecosystems, regardless of rangeland degradation. There is no adequate evidence to prove that severe degraded rangelands in eastern Ethiopia maintain adequate soil seed banks that would improve the condition of it through restoration. Application of efficient management systems and long-term conservation planning in future is therefore important for sustainable use of the natural recourse and livestock production systems in arid ecosystems.

Abstract: Large sediment fluxes can have significant impacts on ecosystems. We measured incoming and outgoing sediment across a gradient of soil disturbance (livestock grazing, plowing) and annual plant invasion for 9 years. Our sites included two currently ungrazed sites: one never grazed by livestock and dominated by perennial grasses/well-developed biocrusts and one not grazed since 1974 and dominated by annual weeds with little biocrusts. We used two currently grazed sites: one dominated by annual weeds and the other dominated by perennial plants, both with little biocrusts. Precipitation was highly variable, with years of average, above-average, and extremely low precipitation. During years with average and above-average precipitation, the disturbed sites consistently produced 2.8 times more sediment than the currently undisturbed sites. The never grazed site always produced the least sediment of all the sites. During the drought years, we observed a 5600-fold increase in sediment production from the most disturbed site (dominated by annual grasses, plowed about 50 years previously and currently grazed by livestock) relative to the never grazed site dominated by perennial grasses and well-developed biocrusts, indicating a non-linear, synergistic response to increasing disturbance types and levels. Comparing sediment losses among the sites, biocrusts were most important in predicting site stability, followed by perennial plant cover. Incoming sediment was similar among the sites, and while inputs were up to 9-fold higher at the most heavily disturbed site during drought years compared to average years, the change during the drought conditions was small relative to the large change seen in the sediment outputs.

Abstract: This study has compared the phytolith production and soil phytolith assemblages of two native grass communities typical in Argentina, namely the monospecific Paspalum quadrifarium community or "pajonal", and the Stipa-Piptochaetium community or "flechillar". Five sites - three of which had been unmanaged while other two had been submitted to fire and fire-grazing management activities - were selected for study. The results show that in these sites a) phytolith production of the plant communities differed due to their diverse floristic composition, b) it was possible to define the type of management or the type of community based on soil phytolith assemblages, c) there were differences between plant communities and soil phytolith assemblages. These results suggest that modern phytolith assemblages are composed not only of local and present vegetation but also of extralocal/regional and probably past vegetation. Hypotheses about the probable processes involved in phytolith incorporation to soil have emerged during the investigation.

Abstract: A market has emerged for carbon sequestered through reforestation. The opportunity to restore ecosystems through this market rather than establish plantations is demonstrated by an Australian case study. In the state of Queensland there are vast areas that have been cleared relatively recently and could be restored to ecosystems with high resilience and important biodiversity values with appropriate management. In order to foster opportunities for carbon accumulation through ecosystem recovery spatially explicit information on sequestration rates, management recommendations, and clear definitions of ancillary biodiversity benefits need to be defined.

Abstract: In this paper, we investigate the ways in which climate stressors and economic changes related to liberalisation alter the local vulnerability context. Household and key informant data from two villages in Mozambique are analysed. First, we explore how changes such as increased market integration, altered systems of agricultural support, land tenure change and privatisation of agro-industries may affect factors important for response capacity, including access to local natural resources, employment opportunities, and household labour and capital. Next, we investigate how people related to the market while coping with the 2002-2003 drought. The study reveals that there had been an increase in informal trade and casual employment opportunities; however, market relations were very unfavourable and as the drought intensified, smallholders were locked into activities that barely secured economic survival and which sometimes endangered long-term response capacity. Only a few large-scale farmers had the capital and skills necessary to negotiate a good market position in urban markets, thus securing future incomes. Inequality, social sustainability, vulnerability and natural resource use are all closely linked in the savannas. Hence, both climate change adaptation policies and sustainability measures need to target vulnerability context and the social and environmental stressors shaping it.

Abstract: Domestic grazing animals that congregate around watering points in arid rangelands create clearly-defined trampling-induced grazing gradients. Grazing and trampling alter soil and vegetation condition, often leading to substantial reductions in ecological function. We measured foraging pits and mounds created by native soil foraging animals over 12 months at three watering points in a Chihuahuan Desert grassland, and hypothesized that the density and cover of their disturbances would increase with increasing distance from water. We recorded an average of 3756 disturbances ha-1 and cover of 34.18 m2 ha-1 across the grazing gradients, which comprised mainly pits (43%) and mounds (25%) of heteromyid rodents, ants and spiders. Soil turnover was estimated at 1.43 m3 ha-1. We detected no differences in density, cover, soil volume or composition of disturbances in relation to distance from water, but there were significant, though ill-defined, differences across the five sampling periods, with generally more activity in the warm-wet months. Small animal-created mounds and pits are important sources of soil and sinks for litter within grazing gradients, and may represent the only sites where plants can establish given a relaxation in grazing pressure.

Abstract: In this study, we assessed the accuracy of the MODIS (Moderate Resolution Imaging Spectroradiometer) GPP (gross primary productivity) Collections 4.5, 4.8 and 5 along with Leaf Area Index (LAI), fraction of absorbed Photosynthetically Active Radiation (fPAR), light use efficiency (LUE) and meteorological variables that are used to estimate GPP for a northern Australian savanna site. Results of this study indicated that the MODIS products captured the seasonal variation in GPP, LAI and fPAR well. Using the index of agreement (IOA), it was found that Collections 4.5 and 4.8 (IOA 0.89 respectively) agreed reasonably well with flux tower measurements between 2001 and 2006. It was also found that MODIS Collection 4.5 predicted the dry season GPP well (Relative Predictive Error (RPE) 4.17%, IOA 0.72 and Root Mean Square Error (RMSE) of 1.05 g C m- 2 day- 1), whilst Collection 4.8 performed better in capturing wet season dynamics (RPE 1.11%, IOA 0.80 and RMSE of 0.91 g C m- 2 day- 1). Although the wet season magnitude of GPP was predicted well by Collection 4.8, an examination of the inputs to the GPP algorithm revealed that MODIS fPAR was too high, but this was compensated by PAR and LUE that was too low. Although LAI and fPAR estimated by Collection 5 were more accurate, GPP for this Collection resulted in a much lower value (RPE 25%) due to errors in other factors. Recalculation of MODIS GPP using site specific input parameters indicated that MODIS fPAR was the main reason for the differences between MODIS and tower derived GPP followed by LUE and meteorological inputs. GPP calculated using all site specific values agreed very well with tower data on an annual basis (IOA 0.94, RPE 6.06% and RMSE 0.83 g C m- 2 day- 1) but the early initiation of the growing season calculated by the MODIS algorithm was improved when the vapor pressure deficit (VPD) function was replaced with a soil water deficit function. The results of this study however, reinforce previous findings in water limited regions, like Australia, and incorporation of soil moisture in a LUE model is needed to accurately estimate the productivity.

Abstract: Camel grazing plays a crucial role in the desert ecosystems of the UAE. In this study, we compare areas grazed by small antelope (Al Maha Resort - the AMR) with areas grazed by both camels and small antelope (Dubai Desert Conservation Reserve - the DDCR). A total of 126 plots were selected during the growing season 2006/07 on three soil substrates: gravel plains, sand flats and sand dunes. In each plot, several vegetation parameters were assessed: density, frequency, percent cover and diversity indices. The replacement of camels with wild antelope has significantly increased the number of species on gravel plains, vegetation density on sand dunes and diversity indices on both sand flats and sand dunes, but significantly decreased plant cover on sand flats and sand dunes. The increase in species diversity in the AMR was attributed to moderate grazing by antelope. Replacement of camels by antelope in the AMR has resulted in change in plant community composition of the three substrate types. Species recovered after protection from camel grazing are palatable, especially for camels, except Heliotropium kotschyi and Aerva javanica. The absence of most of the palatable species from the DDCR was attributed to both selective foraging and overgrazing by camels.

Abstract: Spatially explicit land use/cover models are indispensable for sustainable rural land use planning, particularly in southern African countries that are experiencing rapid land use/cover changes. Using Zimbabwe as an example, we simulated future land use/cover changes up to 2030 based on a Markov-cellular automata model that integrates Markovian transition probabilities computed from satellite-derived land use/cover maps and a cellular automata spatial filter. A multicriteria evaluation (MCE) procedure was used to generate transition potential maps from biophysical and socioeconomic data. Dynamic adjustments of transition probabilities and transition potential map thresholds were implemented in the Markov-cellular automata model through a multi-objective land allocation (MOLA) procedure. Using the normalised transition probabilities, the Markov-cellular automata model simulated future land use/cover changes (up to 2030) under the 2000 calibration scenario, predicting a continuing downward trend in woodland areas and an upward trend in bareland areas. Future land use/cover simulations indicated that if the current land use/cover trends continue in the study area without holistic sustainable development measures, severe land degradation will ensue.

Abstract: Strong sustainability, according to the common definition, requires that different natural and economic capital stocks be maintained as physical quantities separately. Yet, in a world of uncertainty this cannot be guaranteed. To therefore define strong sustainability under uncertainty in an operational manner we propose to use the concept of viability. Viability means that the different components and functions of a dynamic, stochastic system at any time remain in a domain where the future existence of these components and functions is guaranteed with sufficiently high probability. We develop a unifying and general ecological-economic concept of viability that encompasses the traditional ecological and economic notions of viability as special cases. It provides an operational criterion of strong sustainability under a mild form of uncertainty and for medium spatial and temporal scales. We illustrate this concept and demonstrate its usefulness by applying it to livestock grazing management in semi-arid rangelands.

Abstract: This paper examines the incentives driving expansion of rangeland enclosure. It explores the role of customary authorities in defining and enforcing rights to private use of land and attempts to scrutinize whether informal rules emerge to respond to these needs and even become an incentive to establish private enclosures as well as to delineate the processes and actors involved. Based on household level data and group discussion with customary leaders and state agents, results indicate that there are endogenous and exogenous driving forces for range enclosure and change in land use. Institutional diversity is inherent across the cases studied, where this is closely linked to the nature of benefits from enclosure and the underlying incentives. Though signs of state support for enclosure are evident via assessing the role of lower level state administrators in allocation of land for private grazing, policy support for private land use cannot fully explain the gradual shift in de facto property rights. The role of socio-economic and ecological changes is much more important and has widespread influence, where the influence of the former emerges from the economic changes taking place in the rest of the economy, including the rising livestock price.

Abstract: Côte d'Ivoire's adoption of land privatization policies promoted by the World Bank and European Union is producing new land use patterns in the countryside. A centerpiece of these policies is the 1998 Rural Land Law that aims to restructure rural economic life along agrarian capitalist lines. The purported "development" objective of land privatization is to stimulate agricultural productivity based on the assumption that land titling will lead farmers and herders to make greater investments in their production systems. This paper argues that the mobile livestock raising system of immigrant FulBe pastoralists in Côte d'Ivoire is threatened by the new land law. Since mobility is crucial to animal health and fertility rates, I argue that reduced mobility will lead to lower livestock productivity. Although the land law has yet to be implemented, its very existence is leading prospective claimants to test their land rights by planting orchards and lending land to immigrant farmers. The monetization of land lending and grazing rights is increasingly common. Land disputes over who has the power to allocate land are also on the rise. I argue that this heightened interest in "tenure building" is constraining herd mobility, especially for herders with limited resources to negotiate access to rangelands. On the other hand, land privatization is strengthening the hand of local cattle-owning farmers who increasingly practice mobile livestock raising and compete with FulBe herders for grazing lands. Under these new conditions of land access, control, and competition, FulBe herd mobility and productivity are at risk of declining.

Abstract: Ecosystems services sustain humans all over the world. The unsustainable use of ecosystem services around the world has led to widespread degradation which now threatens human health and livelihoods. Although the maintenance of ecosystem services is often used to justify biodiversity conservation actions, it is still unclear how ecosystem services relate to different aspects of biodiversity and to what extent the conservation of biodiversity will ensure the provision of services. The aim of this study was to find out whether biodiversity priorities, biomes, species richness and vegetation diversity hotspots co-occur in space with ecosystem services. The distribution of the ranges and hotspots of five ecosystem services (surface water supply, water flow regulation, carbon storage, soil accumulation, and soil retention) was assessed in South African biomes. Coincidence, overlap, and correlation analyses were used to assess spatial congruence between ecosystem services and species richness (plants and animals) and vegetation diversity hotspots. The grassland and savanna biomes contained significant amounts of all five ecosystem services. There was moderate overlap and a generally positive but low correlation between ecosystem services hotspots and species richness and vegetation diversity hotspots. Species richness was mostly higher in the hotspots of water flow regulation and soil accumulation than would be expected by chance. The water services showed varying levels of congruence with species richness hotspots and vegetation diversity hotspot. These results indicate that actions taken to conserve biodiversity in South Africa will also protect certain ecosystem services and ecosystem services can be used to strengthen biodiversity conservation in some instances.

Abstract: Since the mid-1980s, sagebrush rangelands in the Great Basin of the United States have experienced more frequent and larger wildfires. These fires affect livestock forage, the sagebrush/grasses/forbs mosaic that is important for many wildlife species (e.g., the greater sage grouse (Centrocercus urophasianus)), post-fire flammability and fire frequency. When a sagebrush, especially a Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis (Beetle & A. Young)), dominated area largely devoid of herbaceous perennials burns, it often transitions to an annual dominated and highly flammable plant community that thereafter excludes sagebrush and native perennials. Considerable effort is devoted to revegetating rangeland following fire, but to date there has been very little analysis of the factors that lead to the success of this revegetation. This paper utilizes a revegetation monitoring dataset to examine the densities of three key types of vegetation, specifically nonnative seeded grasses, nonnative seeded forbs, and native Wyoming big sagebrush, at several points in time following seeding. We find that unlike forbs, increasing the seeding rates for grasses does not appear to increase their density (at least for the sites and seeding rates we examined). Also, seeding Wyoming big sagebrush increases its density with time since fire. Seeding of grasses and forbs is less successful at locations that were dominated primarily by annual grasses (cheatgrass (Bromus tectorum L.)), and devoid of shrubs, prior to wildfire. This supports the hypothesis of a "closing window of opportunity" for seeding at locations that burned sagebrush for the first time in recent history.

Abstract: Abstract This study investigated the utilization of mist-belt grassland habitat by the threatened blue swallow and was conducted over three successive breeding seasons in the Blue Swallow Natural Heritage Site at Kaapsehoop, Mpumalanga, South Africa. Blue swallows significantly preferred wetlands over grasslands for foraging. Sufficient foraging habitat must be within a 1.5 km radius from an active nest site. The minimum size of a pair of blue swallows home range should be 333 ha, consisting at a minimum of grasslands (243 ha or 73%) and wetlands (90 ha or 27%). In order to conserve this threatened species, habitat transformation should not take place within a minimum radius of 1.5 km of any blue swallow nest. Due to the critical dependence of the blue swallow on wetland habitat for foraging, any development outside the 1.5 km radius that would affect hydrology and water quality within this range would need to be considered, and any adverse effect mitigated. Rehabilitation of areas to a grassland/wetland mosaic would rather quickly support foraging, and eventually breeding. Although a better understanding of the dynamics between wetlands and adjacent grasslands regarding blue swallow habitat requirements is needed, action can already be taken, based on our results. xD;Résumé Cette étude a examiné l�utilisation de l�habitat de prairie mist-belt par l�hirondelle bleue qui est une espèce menacée et elle s�est poursuivie pendant trois saisons de reproduction successives dans le Site du Patrimoine naturel de l�Hirondelle bleue, à Kaapsehoop, Mpumalanga, en Afrique du Sud. Les hirondelles bleues préféraient de façon significative les zones humides aux prairies pour se nourrir. Il faut qu�il y ait un habitat suffisant pour se nourrir dans un rayon d�1,5 km autour d�un site de nidification actif. La taille minimale pour le domaine vital d�un couple d�hirondelle bleue serait de 333 ha, composé au minimum de prairies (243 ha soit 73%) et de zones humides (90 ha ou 27%). Afin de conserver cette espèce menacée, il faudrait qu�il n�y ait aucune transformation de l�habitat dans un rayon d�au moins 1,5 km de tout nid d�hirondelle bleue. �tant donné que l�hirondelle bleue dépend de façon critique d�une zone humide pour se nourrir, tout développement prenant place à l�extérieur d�un rayon de 1,5 km et qui affecterait l�hydrologie et la qualité de l�eau dans le domaine vital devrait être reconsidéré, et tout effet négatif devrait être atténué. La réhabilitation de zones de mosaïque prairie/zone humide favoriserait assez vite le nourrissage et, peut-être, la reproduction. Bien qu�il soit nécessaire de mieux comprendre la dynamique entre zones humides et prairies adjacentes en ce qui concerne les exigences de l�hirondelle bleue en matière d�habitat, on peut déjà prendre des mesures en se basant sur nos résultats.

Abstract: The Southern African Savannas Network and the Southern African Vulnerability Initiative used study areas and information from a wide range of sources to assess threats and opportunities to savanna sustainability from a natural and social science perspective, respectively. This paper describes an attempt to synthesise their findings using structural analysis. Key driving processes, main dependent processes, and processes that are inherent to most interactions by having both high driving power and high dependency, were identified. Qualitative examination reveals that while many of the changes within savannas reinforce each other, many of the key driving factors are generated externally, such as economic globalisation and climate change. In order to take advantage of opportunities and address challenges within such a complex and dynamic system, future interventions must address the different elements of savannas in a coherent and multi-sectoral manner. Within the large social, economic and environmental changes taking place over the past decade, changes in institutions and technologies and in indigenous fauna and flora continue to play a central role both in driving, and being dependent on, other processes and must continue to be a key focus of any coherent savanna policy.

Abstract: Throughout history non-native invasive species have created environmental, economic, and social problems. Technological change, trade, and land system change are among the key factors in their spread and intensification. A recent global phenomenon holds the potential to exacerbate the invasive species problem: amenity migration, the subdivision of farm and grazing land, and the introduction of alternative land uses and management regimes by new rural residents. An Australian case study explores the subdivision of fine wool sheep ranches, the arrival of amenity migrants, and the impact on the management of one of the country's worst weeds, serrated tussock (Nassella trichotoma). Interviews with property owners, government officials, and members of the community-based conservation group, Landcare, expose cultural, institutional, and economic barriers to the control of the invasive grass. As the subdivision process leads to smaller properties and higher population densities it holds the potential to improve management of serrated tussock if the result is fewer livestock and more people to chemically and mechanically control the grass. But roughly 65% of the newcomers are part-time residents and absenteeism tends to result in weak efforts to manage the weed. In addition, regardless of their full-time/part-time status, most of the newcomers are [`]amenity" landholders whose cultural context and ideas about land and nature is diverse, and who do not seek their primary income from the land. Much of rural Australia now contains amenity landscapes, with weakened social capital, and a reduced capacity to coordinate a response to regional-scale environmental problems.

Abstract: The results from two climate model simulations are used to explore the relationship between North Atlantic sea surface temperatures and the development of African aridity around 100,000 years ago. Through the use of illustrative simulations with an Earth System Climate Model, it is shown that freshwater fluxes associated with ice sheet surges into the North Atlantic, known as Heinrich events, lead to the southward shift of the intertropical convergence zone over Africa. This, combined with the overall increased aridity in the cooler mean climate, leads to substantial changes in simulated African vegetation cover, particularly in the Sahel. We suggest that Heinrich events, which occurred episodically throughout the last glacial cycle, led to abrupt changes in climate that may have rendered large parts of North, East, and West Africa unsuitable for hominin occupation, thus compelling early Homo sapiens to migrate out of Africa.

Abstract: Summary Among the three sites distributed along the West African latitudinal gradient in the AMMA-CATCH observation system, the experimental setup in the Niamey area of south-west Niger samples the cultivated Sahel environment, for hydrological, vegetation and land surface processes. The objective is to investigate relationships between climate, land cover, and the water cycle, in a rapidly changing semiarid environment. This paper first presents the main characteristics of the area, where previous research, including the EPSAT and HAPEX-Sahel experiments, had evidenced a widespread decadal increase in water resources, concurrently with severe drought conditions. The specifics of AMMA-CATCH research and data acquisition at this site, over the long-term (~2001-2010) and enhanced (~2005-2008) observation periods, are introduced. Objectives and observation strategy are explained, and the main characteristics of instrument deployment are detailed. A very large number of parameters - covering rainfall, vegetation ecophysiology, phenology and production, surface fluxes of energy, water vapour and CO2, runoff and sediment, pond water, soil moisture, and groundwater - were monitored at local to meso scales in a nested structure of sites. The current state of knowledge is summarized, connecting processes and patterns of variation for rainfall, vegetation/land cover, and the terrestrial hydrologic cycle. The central role of land use and of its spectacular change in recent decades is highlighted. This paper provides substantial background information that sets the context for papers relating to the south-west Niger site in this AMMA-CATCH special issue.

Abstract: How to improve access to land and livestock production in synergy with ecosystem conservation? The paradigm occurring in natural grasslands of the Southern Brazilian Campos biome is used to illustrate the dilemma. This paper aims to contribute by addressing the technical bases being used by legislations concerning access to land and incentive to production and their consequences for natural grassland systems. Current policies have a production-oriented focus trying to promote livestock productivity by setting minimum stocking rates to be applied in grasslands. The unexpected results are overgrazing and reduction of natural grasslands, so the dilemma production versus conservation emerges. There is a need for adapting access to land legislations to the new environmental functions expected for natural grasslands, which warrant a conservation-oriented approach according to their multifunctional role. Integrated measures are proposed, which could be helpful in resolving the conflicting compromises regarding the inducement of production and the promotion of natural resources conservation.

Abstract: Accurate reconstructions of past hydrological variability are essential for understanding the climate history of the tropics. In tropical Africa, the relative proportion of vegetation utilizing the C3 vs. C4 photosynthetic pathway is mainly controlled by precipitation and thus past hydrological changes can be inferred from the vegetation record. In this study, biomarkers of terrestrial plants (lignin phenols and plant leaf wax carbon isotopes) are examined from a well-dated sedimentary record from Lake Malawi to provide a vegetation (aridity) record of the past 23 cal ka from southeast Africa. We suggest that the ratio of cinammyl to vanillyl (C/V) lignin phenols in Lake Malawi sediments mainly reflects inputs of C3 trees (woody tissue) vs. C4 grasses (non-woody tissue) and find that changes in the C/V ratio generally support variability noted in the n-alkane carbon isotope record. Together, these records provide evidence for increased C4 vegetation (grasses) surrounding Lake Malawi during Last Glacial Maximum (LGM), the Younger Dryas, in the early Holocene, and from ~ 2 cal ka to the present, suggesting drier conditions at these times. Elevated inputs of C3 vegetation are noted in the intervals from ~ 17-13.6 cal ka and ~ 7.7-2 cal ka, indicating wet conditions in southeast Africa. A relationship is noted between the n-alkane average chain length (ACL) and temperature, with longer ACLs associated with higher temperatures. Higher n-alkane carbon preference index (CPI) values correlate with higher mass accumulation rates of biogenic silica and may result from periodic increased northerly winds over Lake Malawi, which enhance upwelling and diatom productivity while simultaneously increasing erosion and transport of plant leaf waxes to the lake. The molecular data produced in this study suggest that the carbon isotopic signature of bulk sediment ([delta]13CTOC) in Lake Malawi is primarily a reflection of terrestrial inputs (C3 vs. C4 vegetation) and may not mainly reflect changes in algal productivity, as previously thought.

Abstract: The dominance of dryland environments in the Southern Hemisphere makes the study of these regions of critical importance for the development of regional, hemispheric and global models of environmental change. Unfortunately, the wetting and drying cycles associated with semi-hyperarid climates are not conducive to the preservation of traditional organic proxy data sources. The last decade, however, has seen the development of a number of alternative archives including the application of luminescence dating techniques to dunes and other aeolian deposits. In continental situations, the existence of relict dune fields has long been thought to be evidence of drier conditions during the Pleistocene, and direct ages from these features have been interpreted almost exclusively as indicating phases of aridity. However, an increasing number of ages from a broader range of environments are calling into question the assumption that aeolian activity can be simply equated with aridity. Presented here is a comparison of dune ages that have been obtained from across southern Africa with a range of proxies from both terrestrial and marine records. Taken as a whole, three primary phases of activity can be identified at ~ 60-40, 35-20 and 17-4 ka. The frequent discordance with other terrestrial records indicating coeval increases in humidity and the close correlation of these phases with wind strength proxies suggest that aridity is unlikely to be the sole, or even primary, forcing mechanism for aeolian activity in the region, and the palaeoclimatic significance of these sedimentary archives needs to be reassessed.

Abstract: Soil erosion is an important process of land degradation in many rangelands and a significant driver of desertification in the world's drylands. Dendrogeomorphology is an alternative to traditional methods for determining soil erosion rate. Specifically, the vertical distance between the upper portion of exposed roots and the actual soil surface can be used as a bioindicator of erosion since plant establishment. In this study, we determined (i) the soil erosion rate from exposed roots of the dwarf shrub Margyricarpus pinnatus [Lam.] Kuntze in two ecological sites in the northeastern rangelands of Patagonia and (ii) the relationship between shrub age and upper root diameter. We selected two ecological sites, a pediment-like plateau and a flank pediment, where the dominant soils were Xeric Haplocalcids and Xeric Calciargids, respectively. The soil erosion rates in the pediment-like plateau and in the flank pediment were 2.4 and 3.1 mm yr- 1, respectively. Data clearly indicate a high rate of soil erosion during the mean 8-year life span of the dwarf shrubs in degraded patches, which represent ~ 10% of surface cover in the study area. Simple linear regression analysis yielded a highly significant predictive model for age estimation of M. pinnatus plants using the upper root diameter as a predictor variable. The measurement of ground lowering against datable exposed roots represents a simple method for the determination of soil erosion rates. In combination with other soil surface features, it was used to infer the episodic nature of soil erosion. This approach could be particularly useful for monitoring the effects of land management practices on recent soil erosion and for the establishment of records in regions where historical data regarding this process are scarce or absent.

Abstract: To restore China's degraded environment, the government launched an environmental restoration project named the "Grain for Green" Project (GGP) in 1999. From 1999 to 2010, the government will spend US$ 40 billion to convert 147 million ha of farmland into forest and grassland and 173 million ha of wasteland (including abandoned farmland) into forest in 25 provinces. A primary focus is to replace farming and livestock grazing in fragile areas with reforestation and planting of forage crops. Given the project's tremendous size and number of participants, the attitudes of the affected farmers will strongly influence the GGP's success. To learn their attitudes, we surveyed 2000 farmers in 2005 to quantify their opinions of the GGP and how it has affected their livelihoods, and we discuss the concerns raised by these attitudes. Farmers appreciated the grain and financial compensation offered by the GGP, but few considered planting of trees (8.9%) or forage species (2.2%) to be a priority. Although only 19.1% felt that their livelihoods had been adversely affected by the GGP and 63.8% supported the project, a large proportion (37.2%) planned to return to cultivating forested areas and grassland once the project's subsidies end in 2018. Therefore, much of the restored vegetation risks being converted into farmland and rangeland again, compromising the sustainability of the environmental achievements. To succeed, strategies such as the GGP must compensate farmers fairly for their costs, create new agricultural products and techniques for use on more suitable land, and create job and training programs that account for the needs and desires of farmers and give them alternatives to returning to old land-use practices.

Abstract: Manure disposal is a major challenge for the fast-growing dairy industry in New Mexico. There are currently over 355,000 milking cows in the state and limited cropland on which to use the manure generated by these cows. On the other hand, 80% of the state lands classified as rangelands are suffering from a lack of organic matter and nutrients. Application of dairy manure to rangelands could serve a dual purpose: (1) manure disposal from dairies and (2) soil amendment to improve soil characteristics and promote herbaceous production. Manure was applied at two rates according to phosphorus (P) content: (1) a recommended (light) rate (54 kg P ha-1) to enhance blue grama growth and (2) a gross over-application (heavy) rate (493 kg P ha-1) to determine the effects on runoff and soil properties. Light applications enhanced soil properties including decreased sediment runoff, increased soil organic matter, increased extractable P, and increased soil moisture, whereas heavy applications increased soil salinity, sodium adsorption ratio, and runoff water. Dairy manure can be safely applied at light rates to conserve and enhance rangeland soil properties and their herbaceous productivity. Manure disposal at heavy rates are unsafe. Further study is required to find out if other safe disposal exists between the light and heavy treatments.

Abstract: Little is known about the effects of grazing on vegetation composition on the Arabian Peninsula. The aim of this study therefore was to analyse the vegetation response to environmental conditions of open woodlands along an altitudinal and a grazing gradient in the Jabal al Akhdar mountain range of Oman. The species composition, vegetation structure, grazing damage and several environmental variables were investigated for 62 samples using a nested plot design. Classification analysis and a Canonical Variate Analysis (CVA) were used to define vegetation types and to identify underlying environmental gradients. The relationship between environmental variables and diversity was analysed using correlation coefficients and a main-effects ANOVA. The plant species richness followed a unimodal distribution along the altitudinal gradient with the highest number of species at the intermediate altitudinal belt. The cluster analysis led to five vegetation groups: The Sideroxylon mascatense-Dodonaea viscosa group on grazed and the Olea europaea-Fingerhuthia africana group on ungrazed plateau sites at 2000 m a.s.l., the Ziziphus spina-christi-Nerium oleander group at wadi sites and the Moringa peregrina-Pteropyrum scoparium group at 1200 m a.s.l, and the Acacia gerrardii-Leucas inflata group at 1700 m a.s.l. The CVA indicated a clear distinction of the groups obtained by the agglomerative cluster analysis. The landform, altitude and grazing intensity were found to be the most important variables distinguishing between clusters. Overgrazing of the studied rangeland is an increasing environmental problem, whereas the plant composition at ungrazed sites pointed to a relatively fast and high regeneration potential of the local vegetation.

Abstract: The study examines the changes in sub-Saharan's natural land cover resources for a 25 year period. We assess these changes in four broad land cover classes - forests, natural non-forest vegetation, agriculture and barren - by using high spatial resolution Earth observing satellites. Two sets of sample images, one [`]historical' targeted at 1975 and a second [`]recent' targeted at the year 2000, have been selected through a stratified random sampling technique over the study area, targeting a sampling rate of 1% in each of the strata. The results, presented at eco-region level and aggregated at sub-Saharan level, show a 57% increase in agriculture area at the expense of natural vegetation which has itself decreased by 21% over the period, with nearly 5 million hectares forest and non-forest natural vegetation lost per year. The impacts of these changes on the environment on one site and on the socio-economy on the other site are discussed and possible pressures on human well being are highlighted.

Abstract: Summary Soil moisture is widely recognized as a key parameter in environmental processes mainly for the role of rainfall partitioning into runoff and infiltration. Therefore, for storm rainfall-runoff modeling the estimation of the antecedent wetness conditions (AWC) is one of the most important aspect. In this context, this study investigates the potential of scatterometer on board of the ERS satellites for the assessment of wetness conditions in three Tiber sub-catchments (Central Italy), of which one includes an experimental area for soil moisture monitoring. The satellite soil moisture data are taken from the ERS/METOP soil moisture archive. First, the scatterometer-derived soil wetness index (SWI) data are compared with two on-site soil moisture data sets acquired by different methodologies on areas of different extension ranging from 0.01 km2 to ~60 km2. Moreover, the reliability of SWI to estimate the AWC at a catchment scale is investigated considering the relationship between SWI and the soil potential maximum retention parameter, S, of the Soil Conservation Service-Curve Number (SCS-CN) method for abstraction. Several flood events occurred from 1992 to 2005 are selected for this purpose. Specifically, the performance of the SWI for S estimation is compared with two antecedent precipitation indices (API) and one base flow index (BFI). The S values obtained through the observed direct runoff volume and rainfall depth are used as benchmark. Results show the great reliability of the SWI for the estimation of wetness conditions both at the plot and catchment scale despite the complex orography of the investigated areas. As far as the comparison with on site soil moisture data set is concerned, the SWI is found quite reliable in representing the soil moisture at layer depth of 15 cm, with a mean correlation coefficient equal to 0.81. The characteristic time length parameter variations, as expected, is depended on soil type, with values in accordance with previous studies. In terms of AWC assessment at catchment scale, based on selected flood events, the SWI is found highly correlated with the observed maximum potential retention of the SCS-CN method with a correlation coefficient R equal to -0.90. Besides, SWI in representing the AWC of the three investigated catchments, outperformed both API indices, poorly representative of AWC, and BFI. Finally, the classical SCS-CN method applied for direct runoff depth estimation, where S is assessed by SWI, provided good performance with a percentage error not exceeding ~25% for 80% of investigated rainfall-runoff events.