• Major achievements: `The vegetation change data and figures and the land use data and figures in different stages for the last 50 years in the upper Yangtze river (middle and lower section, focus on the Chuanjiang valley and the Three Gorges reservoir area.(GIS system database) aThe hydrologic effects and function area classification of typical forest communities. (Prototype, model, reports) bThe formation characteristics of sediment, and its control measures about different land use patterns. (Prototypes software, thesis) cThe benefits evaluating methods and the indicators system about vegetation ecological shields. (Prototypes, reports) dThe response and recommendations for ecological management and ecological compensation of the valley water resources(reports, proposals r) This research project aims to make a series of outstanding achievements on the study such as the scale effects about forest hydrologic effects, the forest natural succession mechanism and its dynamic simulation, the moving and control of sediment into river, the evaluation,indicators system about vegetation ecological effects and publish more than 60 research papers in the core publications (15 per year), among theses, 15 research papers in SCI or EI publications , and publish 5 monographs, and produce 2 sets of observation database and GIS information system respectively (more than 500 MB accumulation data), and put forward 5 principal counsulting reports. (2) Dynamics of alpine forest ecosystems and its relationship with Global Change •Project types:Under the auspices of the National Key Project for Basic Research on Tibetan Plateau •led by:Professor Luo Ji, IMHE, South Renming Road, Chengdu, Sichuan. Tel:028-85229891. E-mail: luoji@imde.ac.cn •Participants: Professor Cheng Genwei; Associate professor Song Mengqiang •directed by: Institute of Mountain Hazards and Environment, Chinese Academy of Sciences & Ministry of Water Conservancy •Duration: 1997^2000 •Key words: Alpine, Ecosystem,Carbon cycle •Research fund: 30,000 Yuan RMB •Objectives: To explore carbon cycles of alpine forest ecosystems on Tibetan Plateau, to built a carbon cycle model which will be used to simulate the dynamics of alpine forest ecosystems and its relationship with Global Warming, so that it can support the conservation of the natural forests in upper reaches of Yangtze River and eco-environmental security on the strategic plan of Western Development in China. Main themes: According to the dynamic changes of the structure and function of alpine forest ecosystems, we studied the productivity and biomass components of different forests, measured the nitrogen and carbon flux of ecosystems. All these are helpful to reveal the mechanism of nitrogen and carbon cycles of alpine forest ecosystems and to build nitrogen and carbon cycle model that will be used to simulate the dynamics of alpine forest ecosystems. We conclude our study by discussing our results in relation to both the domestic & international literature on soil respiration. Our aim is to compare our results with other research by measuring the soil respiration of different kinds of soil, to understand the relationship between degeneration and restoration process of alpine forest ecosystems with global climate change and to guide the practice of restoring degraded forest ecosystems and maintenance of their functions. Major achievements: •Environment of vertical zones and vegetation primary successional sere •Nitrogen and carbon dynamics of soil types and pedogenic properties on different time scales •The main influencing factors of nitrogen and carbon cycle •Nitrogen and carbon cycle model of alpine forest ecosystems •Simulating the dynamic changes of alpine forest ecosystems with global climate change in the future Through the research on zonal vegetation, vegetation primary successional sere and degraded forest ecosystems, we have made suggestions on ecosystem health indicators and optimized control techniques for sub-alpine dark coniferous forests and built the recovery and reconstruction demonstrating base on degraded forest ecosystems.