Prof. Dr. Cindy Q. Tang specializes in forest ecology, restoration ecology and conservation of relict, endangered and rare plant species. She has a long-standing interest in forest dynamics, interaction between plant species, also species and their environment. Her research concentrates particularly on the mechanisms underlying the structure and dynamics of subtropical forests and sustainable development of forests in southwestern and south-central China.
Abstract: Since 1985, originally forested mountainous areas of China have been allowed to return to their natural state after years of exploitation including agriculture, development, and logging. The reforms began earlier in less accessible locations, so that today the successional process is more advanced there. The vegetation in Luquan, Qiongzhusi and Xishan near Kunming, central Yunnan, exhibits, in a limited area, a range of stages of plant succession that are widely encountered throughout the broader region, and thus affords a special opportunity for a comprehensive study. We analyzed the successional sequence of these various plant communities. They ranged from pioneer coniferous and/or pioneer deciduous broad-leaved stands to pre-mature semi-humid evergreen broad-leaved stands, through mixed coniferous and broad-leaved or mixed deciduous and evergreen broad-leaved stands. The succession proceeded from pioneer coniferous Pinus and Keteleeria, and deciduous Platycarya and Alnus, to late-successional evergreen broad-leaved Cyclobalanopsis and Castanopsis.
Two regeneration types of woody species in either the early-successional (15-50 years), the mid-successional (40-80 years), or the late-successional (80-180 years) stage were classified. Relatively high species diversity was found in the seral phase at the three study sites.
The late-successional stage was commonest where human disturbance was least evident. Poor soil chemical properties under pioneer Pinus were seen as a limitation to plant growth, while the abundance of Alnus at the early stage led to an improved level of organic matter and nitrogen.
Abstract: Subtropical evergreen broad-leaved forests of Yunnan, China, including mid-montane moist, monsoon, and semi-humid categories, were studied in terms of ecological attributes of pertinent species, diversity, structure, dynamics and succession, as compared with the subtropical/warm-temperate evergreen broad-leaved rain forest of SW Japan. The genera and species of the forests of Yunnan and SW Japan are East Asian elements and indicate a very close relationship between the respective floras, though different assemblages of species occur in the two regions. Diversity indices and numerical data on taxon richness at family, genus and species level were similar in both regions. Four types of gap-regeneration behaviors among the major tree species were recognized in the two areas. In both, as a result of long-term human activity, the plant communities ranged from pioneer deciduous broad-leaved and/or pioneer coniferous stands to late-successional evergreen broad-leaved stands. Succession in the two regions followed parallel paths, beginning with pioneer Alnus in Yunnan and Alnus, Mallotus and Styrax in Japan, accompanied by coniferous Pinus in the two areas, and with late-successional evergreen broad-leaved Cyclobalanopsis and Castanopsis as their final stage.
Abstract: Two mid-montane moist evergreen broad-leaved forests on the Ailao Mountains, Yunnan, and one on Mt. Emei, Sichuan, SW China were studied with reference to forest structure and dynamics based on size, age, canopy gaps, regeneration modes and the survival of seedlings. The most dominant canopy tree species are Lithocarpus xylocarpus, Castanopsis wattii, Castanopsis remotidenticulata, Lithocarpus craibianus, Castanopsis fabri and Castanopsis platycantha of Fagaceae along with Machilus viridis and Machilus gamblei of Lauraceae, Schima noronhae and Schima sinensis of Theaceae. The vertical structures of the forests were multi-layered. All the canopy species had multimodal-shaped size and age distributions. In each forest of the study sites, the average size of a canopy gap was smaller than 65 m2, caused mainly by the death of canopy trees. Overall, gap formation in the study forests was a relatively continuous and small-scale process. No individuals under 30 years old were found for Lithocarpus xylocarpus. Castanopsis wattii, Lithocarpus craibianus and Castanopsis fabri regenerated mainly by sprouts. Machilus viridis, Machilus gamblei, Castanopsis remotidenticulata and Castanopsis platycantha regenerated by both seedlings and sprouts. Schima noronhae and Schima sinensis were found regenerating by means of seedlings. No surviving seedlings of Fagaceae species were found in understories having bamboo with a coverage greater than 25% in any quadrat of the three forests. The higher the coverage of bamboo, the fewer surviving seedlings were found for the woody species. The poor seedling bank in the study forests may be due to the presence of dwarf bamboo Sinarundinaria nitida and Bambusa stenostachya in the understory.
