Achievement of Research 1 Project Name: Comparative Researches on the Dynamics of Habitats, Species and Communities structures at different growth stages of tropical forest Category: Key Research Project of CAS Chair Person: Caomin Professor Address: 88, Xuefu Road, Kunming, 650223 E-mail: caom@xtbg.ac.cn Tel: 0871-5160998; Fax: 0871-5160916 Major Participants: Zhang Yiping, Sha Liqing, Zheng Zheng, Tang Jianwei, Yang Xiaodong, Tang Yong Leading agency: Xishuangbanna Tropical Botanical Garden, CAS Time: 1997 ~ 2000 Objectives: To reveal the dynamic growing process of tropical rain forests at different times. Provide theoretical ground for explaining the inner forces of forest dynamics and offer guidance for forest recovery and management. Contents: comparative ecological studies on forest community constituents of mature rain forest, community-formulating rain forests and forest opening period. Major results: ?For the first time, the project adopts comparative ecological approaches to research systematically on seasonal rain forest at forest gap, build and mature stages. The researches involve forest environment (micro-climate and soil), species composition (plants, undergrowth insects and soil wildlife species) of communities at different stages and the characteristics of community structure. With this done, the project summarizes the regional features of seasonal rain forest regeneration in Xishuangbanna and establishes the model of regeneration. Relative studies abroad generally focus on individual field instead of a systematic approach, not to mention the comprehensive researches on forest fragmentations at different stages of growth. Finally, the ecological dynamic principles can be revealed. And this, the project is creative and systematic in terms of its designing concepts and researches. The researches on forest gap at the early stages of forest formation, forest edge micro-climate characteristics and radiant energy climate indicate there exists a new heat surface a vertical functional surface (forest wall) in the forest opening. The researches also propose that the forest edge micro-climate is the result of the interactions among 4 heat functional surfaces (the one inside the forest, surface outside forest, canopy and forest edge wall). The heat functions are different in different seasons. This plays a key role in explaining forest edge effect and forest gap micro-climate. Studies on the forest openings show that in the dry season, because the combined influence of sun light, weather conditions and forest gap trees, the temperature of the forest gap is of diversified characteristics. The horizontal distribution of temperature is asymmetric and moves according season changes. The spot with highest temperature is not located in the center of the forest gap, instead, it occurs in the east-northeast part of the forest edge. This feature is most conspicuous at noon. As one of the heat functional surface of the forest opening, the surface of forest opening sees great differences in terms of temperature elements at different item of the day. The asymmetric characteristics of the distribution of micro-climate in the forest opening will surely bring about different heat functions at different spots within the forest opening which in term result in differences in heat transference and storage in forest openings, hence different heat effects. ?It is previously believed that the salivation rate of soil will increase after forest being disturbed. But researches done on human interference (slash and burning farming) and natural disturbances (tree felling) of forest communities show that the salination rate of rotating farmlands and forest opening is far below than the mature forests and the community formation forests. This reason for this is that there is less organic and nitrogen content in the former soil. This also shows that, apart from water and temperature factors, the nitrogen sources of soil is an important factor affecting soil salination rate. ?Comparative studies on photosynthesis of dominant species in forest communities at different growth stages indicate that the photosynthesis rate and compensation point and leave hidden breathing rate of pioneering species is bigger than the dominant species. This difference affects the survival ability of different species of plants and the result of competition. In the mature communities, the dominant species such as Pometia tormentosa young trees in the upper layer of the canopy has better adaptability in photosynthesis than other young trees of dominant species and thus are better adapted to the environment changes either under the canopy and in the forest openings. ?Based on the research data of seed rain of mature forests, the project proposes, for the first time, the hypothesis that there is a Mosaic cyclic mechanism within the dominant species of monsoon rain forest rain. This establish a new theoretical framework at revealing the configuration principle in terms of time of monsoon rain forest seed input. At the same time, this opens up new concepts of further study and explanation on the origin and sustaining mechanism of soil seed bank in the monsoon rain forest. ?Based on the data of dynamic studies on young tree, the project, for the first time, proposes the hypothesis of Self-compensatory mechanism of monsoon rain forest ecosystem. This is of great significance at revealing Seedling breakout of forest recovery exists at different growing stages of forest development. This is an important breakthrough in the theory of monsoon rain forest renovation. ? Based on the research findings concerning the characteristics of soil seed bank, seed rain and young trees at different stages of forest development forest opening, community formulation and mature stage, the project first establishes the renovation module of monsoon rain forest and provides new theoretical foundation for vegetation recovery and forest management for the Xishuangbanna area. ?Through the researches, the project proposes the concept that the characteristics of soil seed bank and seed rain are important indicators is assessing degraded ecosystem recovery potentials. The project also explores and summarizes a corresponding technology to contribute to the vegetation recovery practices and forest management. ?The project publishes 24 research papers, 2 of which are included in SCI, 19 are included in CSCD and 3 are published on distinguished journals. At the same time, the manuscript of the book Dynamic Ecological Research of Tropical Monsoon Forest has been finished. 2 Project Name: Studies on the Shorea chinensis metapopulation in Xishuangbanna Category: National Natural Science Funding of China Chair Person: Tang Jianwei Associate Professor Address: Menglun Town, Mengla County, Yunnan Province, 666303 E-mail: tangjw@xtbg.org.cn Tel: 0871-8715080; Fax: 0871-8715070 Major Participants: Sha Liqing, Xue Jingyi, Liu Wenjie, Zhang Guangming Leading agency: Xishuangbanna Tropical Botanical Garden,CAS Time: 1999 ~ 2001 Objectives: Through the researches on seed dispersal, germination, structural characteristics, population changes, rehabilitation ability and habitat conditions of Shorea chinensis population at different habitat patches, get to know changes of local population in different patches and reveal relationship between local population and metapopulation and the environment; clarify the endangered mechanism, process and dynamic changes principles of Shorea chinensis population and provide theoretical evidence to protect the species effectively. Major Contents ?Seed diffusion behavior and germinating status of local population. ?Structural characteristics and number dynamics of metapopulation ?Rehabilitation ability of metapopulation. ?Impact of environment factor dynamics in different patches on metapopulation ?Establishment of Shorea chinensis metapopulation dynamic model. ?Viability of Shorea chinensis metapopulation. Research Results ?On the plot investigation of Shorea chinensis population in Mengla County shows that, in the last years, the Shorea chinensis (listed as first grade protected in China) population have been fragmented because of the intensified production and economic activities. Now, altogether 19 patches of different sizes exist on the steep slopes along the Nansa, Basha, Huiying, Huigeng, Huidu and Nanhang Rivers. According to the calculation based on 1:50,000 map, the smallest patch is 0.45ha and is surrounded by farmlands. The largest patch is 350ha. Amomum villosum has been planted in all the patches. ?The observations carried out very other 2 days on 3 patches along Nansha River, Bangsong Valley and Baisha River indicate that amount of seed, death conditions vary greatly from patch to patch. The germinating rate is 93-96.0% while the death rate is 81-86%. The difference in amount of seed is determined by the number of fruit bearing trees in different patches, while the death rate is determined by the habitat conditions of different patches. The death after germination is caused by molding and decay because of the rain season and inadequate sunshine and high humidity. Although the seed of Shorea chinensis has 3 long and 2 short wings, it never travels beyond 100 m away from the mother tree, thus most seeds are concentrated near the mother tree. ?Observation data on 20 quadrants (2m?m ) on 7 different patches shows that the habitat and number of fruits born by each mother tree are different, hence there are differences concerning the density of young tree (H<100cm) and death rate. ?According to the 3 year-long observation on different habitats (secondary, forest opening and undergrowth), the young tree density is the largest in secondary forests, followed by forest openings and undergrowth. The death rate is the largest in secondary forests, followed by undergrowth and forest openings. The death rate of different habitats declines as time goes on. The pattern of seasonal changes is: the fastest growing season is in the cool season (Dec.-Mar.) and the slowest period is the rain season ( Jun.-Sept.) and the death rate is the biggest in the rain season and the lowest in the cool season. ?Two soil sample analysis before and after rain season in 8 different patches shows that the surface soil layer between 0~10cm sees the richest nutrients and in the layer between 10~25cm, the nutrient contents decline. The nutrient content before the rain season is bigger than that after the rain season. The nutrient content in the soil layer of 0~10cm in different patches varies greatly. ?Observation on the micro-climate in the dry and rain season of 4 different patches indicates that the daily temperature difference of increases as the area of the patch declines; temperature drops and stabilizes from the forest edge to inside of the forest in different patches. The largest patch (in Bangsong Valley) sees the fastest dropping and the smallest patch sees the slowest dropping. The surface temperature, wind speed, humidity of atmosphere of different patches increase (turning drier) as area of patch diminishes. The relative humidity increases from outside the forest to inside of the forest. This is the most obvious in the largest patch. There is very clear micro-climate effect on every edge of the patches. ?Because Amomum villosum cultivation has become a major source of income for the local population, a lot of Amomum villosum has been planted in the Shorea chinensis forests. Studies on the 8 quadrant in the 5 patches show that, compared to the well protected patches, patches with Amomum villosum plantations loss 80% 95% Shorea chinensis individuals and these losses are mainly young trees, which in turn causing the Shorea chinensis communities lose renovation and development foundation and hence the survival of Shorea chinensis communities is critically endangered. This situation is resulted from Amomum villosum cultivation during which young trees are cleared in nursing Amomum villosum. ?Investigation on quadrants (1000m2) of rehabilitation Shorea chinensis communities formed after slash and burn farming shows that the Shorea chinensis communities density (22 years old) in along Huiying River is 5440 trees/ha density in Bangsong Valley is 20,920 trees/ha. The community age structure is on the rise and a community age structure module has been established. ?According to the established Shorea chinensis growth model and field quadrant investigation data, the age of individual trees in different patches is calculated and Shorea chinensis community and the whole Shorea chinensis heterogeneous live circle has been determined. The result shows the density of different patches varies greatly and there is direct connection with the area of the patches. The community density is 12,613 tree/ha 25,475 tree/ha. The number of young trees in each patch is abundant and the age structure is on the rise. This is especially the case on two patches where the big trees have been cut. Key words Shorea chinensis Metapopulation, Minimum viable population, Population viability Research Fund 130,000 yuan 3 Project Name Impact of Invasion Species on Plant Community Succession Directionality and Ecological Functions Category: Subsidiary project of key CAS Project Yunnan Province Natural Science Fund Chair Person: Tang Jianwei Associate Professor Address: Menglun Town, Mengla County, Yunnan Province, 666303 E-mail: tangjw@xtbg.org.cn Tel: 0871-8715080; Fax: 0871-8715070 Major Participants Sha Lingqing, Xue Jingyi, Zhang Guangming, Shi Jipu Leading agency Xishuangbanna Tropical Botanical Garden,CAS Time 1998 ~ 2001 Objectives: Through the researches on biological and ecological characteristics of whangee (Dendrocalamus membranceus) and wild banana (Musa itinerans) and the constituents of species during invasion process and the analysis on chemical elements and soil factors dynamics, clarify the invasion process, mechanism and impact on community succession and the entire ecosystem; provide scientific evidence for degraded ecosystem recovery and rehabilitation. Major Contents ?Ecological adaptability of whangee (Dendrocalamus membranceus)and wild banana (Musa itinery) ?Biological features and growing process of whange (Dendrocalamus membranceus) and wild banana (Musa itinery). ?Species diversity of whangee (Dendrocalamus membranceus) and wild banana (Musa itinery)community at different ages. ?Element contents of whangee (Dendrocalamus membranceus) and wild banana (Musa itinery). ?Dynamics of soil environment factors in whangee (Dendrocalamus membranceus) and wild banana (Musa itinery) at different stages. Research Results ?Whangee (Dendrocalamus membranceus)and wild banana (Musa itinerans) are two typical pioneering species in the tropical rain forest in southern China and both species have very strong ecological adaptability. The reason why they become pioneering species (invasion species) is because both species have strong root systems and clone the mother plant. ?Researches on three adjacent wild banana communities on the same slope show the communities formed after slash and burning farming develop in the direction with more species and genera as time goes by. The investigations on Shannon-Wienner indicators of the 3 communities show that as community develops, the diversity and evenness of invasion species increase at the invasion and rehabilitation periods and at the expansion period, the diversity declines in the upper layers, while at the same time the diversity indicators and evenness increase in the lower layers. The structure of the community becomes more complicated as the succession progresses; the dominant species in each community is very conspicuous with wild banana being the overwhelming species. The total population of wild banana tree is much bigger than other species and it continues to increase as the age of forest adds. ?The secondary communities formed after slash and burning farming undergo very big impact of community species changes because the invasion of whangee (Dendrocalamus membranceus) After the habilitation period, the diversity of species, genera and family of community become monotonous and scarce. The monitoring results of plant diversity in different communities show that as community develops, the diversity and evenness of invasion species increase at the invasion and rehabilitation periods and at the diffusion period, the diversity declines in the upper layers, while at the same time the diversity indicators and evenness increase in the lower layers. The structure of the community becomes more complicated as the succession progresses; the dominant species in each community is very conspicuous with whangee (Dendrocalamus membranceus) being the overwhelming species. The total population of whangee (Dendrocalamus membranceus) is much bigger than other species and communities with whangee (Dendrocalamus membranceus) as the dominant species develop. ?The biomass of wild banana communities increases from the invasion period to the habilitation period as the forest age adds, while from the habilitation period to the diffusion period, the biomass declines. The situation with whangee (Dendrocalamus membranceus) communities is quite identical to that of wild banana tree. ?The population and community of young wild banana tree show a reverse ratio with the age of the forest. That is, the older the forest, the smaller the density of the wild banana trees and vice versa. The population and growth dynamics is closely related to the density in that the smaller the density, the lower the death rate of the young trees and the faster grow and vice versa. However, the situation of whangee (Dendrocalamus membranceus) is quite different in that as the age the of forest adds, the germination of shoots increases. Because of the differences of habitats, the average ration of growth declines as community age grows. ?As the individual grows, changes in the density of chemical elements in different organs occur: the Ca and Mg content in the new leaves drops as tree age grows, while that content in other organs increases. The content of all other elements except N drops in the new leaves. The same is with the content of N, P, K, S in the trunk and old leaves; in the root system, the content of S, N, K, in the main root and content of N, P, S of the minor roots drops as age adds, while the content of P in the main root and content of K in the minor roots increases. In the wild banana tree communities of different ages, the total content of elements increases as the biomass of the community increases. Element analysis on the different organs (trunk, leave, branch and root) of whangee (Dendrocalamus membranceus) shows that the content of N in the leaves increases as age adds while its content in other organs drops at the same time. Ca and Mg increases as age adds and the content of S and P does not show any changes in the root system and drops in the leaves. The content of K in the leaves and branches drops but increases in other organs. ?At different stages of community succession, the soil nutrients show clear differences in the wild banana (Musa itinerans) communities, namely the content of nutrients drop as succession progresses. The organic compounds, N and P contents are the highest at the invasion period, 5.879% 0.333% 0.0632% (upper layer) respectively and lowest at the settlement period, 3.541% 0.240% 0.045 respectively (upper layer). At the same time, the organic compounds, N and P contents drop as the soil becomes thicker and the differences in soil nutrients become smaller. From the settlement period to the diffusion period, the dropping of P content in the surface soil (26%) is bigger than middle 21% and lower 20% layers of soil. In the middle layer, the P content clearly drops, only 75.0% of the invasion period. The K content is the highest at the settlement period 1.516% , followed by invasion period (1.085%) and diffusion period (0.862%). The changes of effective nutrients of wild banana (Musa itinerans) community at different succession stages are in line with the overall content of the nutrients of the community. Except for Mg content, the effective nutrients decrease as succession progresses. The seasonal changes of soil nutrients in different communities are most conspicuous at the surface layer. After March, soil nutrients content drop to various extent and the trend continues until the end of the rain season when the content increases again. By November, except the K content which is slightly higher than the previous year, all the content of other elements are lower than the previous year. The range of seasonal changes of nutrients is: diffusion period >invasion period >settlement period and the order of nutrients changes is: P>K>O.M>N. The seasonal changes of effective soil nutrients are bigger than the overall nutrients content. The order of changes scope is: K>P>Mg>Ca>N ?The organic compound of whangee (Dendrocalamus membranceus) communities at different succession stages drops as the communities grow older. There is much difference between the overall N content among the communities, but is drops as the community becomes older and the soil layer goes deeper. The effective N content of each community drops as the soil layer goes deeper. The overall P content of each community increases as the community grows older. The seasonal soil nutrient change patterns are: from November to May, it drops, and increases from May to November. The organic compound in each community does not change much and the seasonal changes of N, P, K content is similar to that of organic compounds. Different researches mentioned above shows that the formation and development of wild banana (Musa itinerans) communities do not impose impact on the community succession direction and ecosystem function. However, whangee (Dendrocalamus membranceus) has very strong growing ability and it absorb large amount of water and nutrients, making it hard for other species to compete thus it become the overwhelming community and reducing the nutrient contents of soil and the surface soil hardens, thus bring large impact on the community succession direction and ecosystem functions. Key words: invasion species, biological and ecological characteristics, influencing mechanism Research Fund 260,000 yuan 4 Project Name Research on the impact of slash and burning cultivation on nitrogen biogeochemistry recycling in tropical forest ecosystem Category: Yunnan Province Natural Science Fund Chair Person: Sha Liqing Associate Professor Address: 88, Xuefu Road, Kunming, Yunnan, 650223 E-mail: shalq@xtbg.ac.cn Tel: 0871-5112637; Fax: 0871-5160916 Major Participants Zheng Zheng, Feng Zhili, Meng Ying Leading agency Xishuangbanna Tropical Botanical Garden, CAS Time 1997 ~ 2000 Objectives: Obtain data on the nitrogen sedimentation and chemical characteristics of surface water in the research area; reveal the nitrogen biological, chemical recycling principle of the tropical monsoon rain forest ecosystems in Xishuangbanna and impact of slash and burning cultivation on the nitrogen recycling of the ecosystem; provide theoretical ground and practical guidance for effective forest resources management and exploitation. Major Contents ?Nitrogen sedimentation input: total sedimentation, stemflow, nitrogen composition and content in the water penetrating canopy; ?Water recycling characteristics in the seasonal rain forest, plantations and fellow farmlands; ?Nitrogenization and sallination characteristics in different systems; ?Impact of forest gap on soil nutrients; ?Seasonal changes of soil moisture; ?Comparison between the recycling features of nitrogen in two different ecosystems seasonal forest and fellow farmland; reveal the impact of slash and burning cultivation on nitrogen recycling; ?Ecological benefit of green fertilizer and terraced farmlands. Research Results ?The overall nitrogen content in the soil (0 100cm) of tropical monsoon rain forest in Xishuangbanna is 12.71t/hm2 and the content drops from the surface downward. The nitrogenization rate of monsoon rain forest, 30 year old secondary cliff forests and forest opening and farmlands (0~10cm) is 6.55 6.37 7.85 and 10.69 mgN/kg/30d respectively. ?The total nitrogen reserve of the monsoon rain forest in Xishuangbanna is 6,481.2 kg/hm2 and the nitrogen reserve of living biomass, litter layer and soil (0~30cm) is 970.9 kg/hm2, 37.7 kg/hm2 and 5481.2 kg/hm2 respectively. The nitrogen in the soil takes up 84.4% of the nitrogen in the whole ecosystem and that of living biomass and litter layer is 15.0% and 0.6% respectively. This shows that the nitrogen of the monsoon rain forest is mainly distributed in the soil, contrary to the commonly belief that it lies in the living biomass. ?The nitrogen content in the rainfall, water penetrating canopy, stem flow and surface flow in Xishuangbanna tropical seasonal rain forest is 0.565, 0.828, 0.983 and 1.042 mg/l respectively. The nitrogen flux is 8.89, 10.97, 3.57 and 5.95 kg/ hm2/a respectively. The input of nitrogen from rainfall is 8.89 kg/ hm2/a and the output is 5.95 kg/ hm2/a, hence a balance of 2.94 kg/ hm2/a. the recycling pattern is: absorbing 149.86 kg/ hm2/a , residue 69.30 kg/ hm2/a and returning 80.56 kg/ hm2/a and the recycling ratio is 0.54. This shows there is nitrogen accumulation in the undisturbed ecosystem, which is of benefit for the steady and sustainable development of the ecosystem. ?Slash and burn cultivation on soil nutrients: in the soil layer of 0-10cm, pH value, organic compound, N, P, K clearly increased. But in the soil layer of 10-30cm, there is not much change concerning the indicators mentioned above. The C/N ratio change is not obvious after slash and burning farming. ?Impact of forest opening on soil nutrients: the organic compounds, N, P, effective P and sallination in the soil under canopy is 2.713%, 0.140%, 0.077%, 14.56 mg•kg-1 and 16.28 mg NO3-N kg-1•30 d-1 respectively, much higher than those in the soil in the forest opening 1.316%, 0.093%, 3.84 mg•kg-1 and -2.78 mg NO3-N kg-1•30 d-1 respectively. But there is little difference concerning net nitrogen mineralization rate, amination rate and NO3-N and NH4-N concentration between the two. ?The soil erosion rate of seasonal rain forest, rubber tree plantation and farmland is 0.48, 0.32 and 8.12 t/ hm2/a respectively. The soil erosion rate of farmland is 16.9 times that of rain forest and 25.4 times of rubber plantation. Human activities such as logging, slash and burning farming and slope farmlands farming will increase the soil and water erosion and the undisturbed ecosystem can conserve water and soil effectively. Key words tropical rain forest, slash and burn cultivation, biological, Biogeochemistry recycling Research Fund 60,000 yuan 5 Project Name: Studies on the Habitat Heterogeneity and Physiological Ecology of Gap Regeneration in Tropical Rain Forest Category: National Natural Science Fund of China Chair Person: Li Qingjun Professor Address: Menglun Town, Mengla County, Yunnan Province, 666303 E-mail: lqjxtbg@xtbg.ac.cn Tel: 0691-8715471; Fax: 0691-8715070 Major Participants: Zhang Jianhou, Zhu Hua, Liu Hongmao, Tang Jianwei, Xia Yongmei, Liu Wenjie Leading agency: Xishuangbanna Tropical Botanical Garden, CAS Time: 1998 ~ 2000 Objectives: This project targets at two typical communities Shorea chinensis and Terminalia myriocarpa + Pometia tomentosa with the aim of studying the time and spatial heterogeneity under environment conditions of forest gaps of different sizes and structure, the dynamics of important plant species during the process of forest gap Succession, the photosynthesis rate and water use efficiency of tree lings at different stages. The final goal is to reveal the physiological ecology of the plant species and explain the Succession mechanism of tropical rain forest and provide scientific evidence and guidance for biodiversity sustainability and tropical forest recovery in China. Major Contents: The research targets at Shorea chinensis and Terminalia myriocarpa + Pometia tomentosa communities in tropical rain forest and focuses on the study of forest opening environment (sunshine, temperature, water and soil) changes, the constituents and distribution of different species in the forest openings, the dominant species (mainly Shorea chinensis and Terminalia myriocarpa + Pometia tomentosa) and the physiology (characteristics of photosynthesis and water use efficiency) of pioneering species at the early stages of forest openings and their requirements of environment and adaptability. And finally get to know the Succession dynamics and physiology of Shorea chinensis and Terminalia myriocarpa + Pometia tomentosa. Research Results: Within 3 year s research, the project analyzes the formation reasons, distribution, species composition and structure dynamics of forest openings in the tropical rain forest; it reveals the characteristics and rules of environment changes of forest openings in the tropical rain forest; the project also discovers the Succession dynamics, biodiversity changes and the interaction of photosynthesis and water use efficiency of major species in the forest openings. With the conclusion of the project, 5 papers have been published in journals. Key words: Tropical Rain Forest, Regeneration Dynamics of Forest gap and Physiological Ecology Research Fund: 120,000 6 Project Name: Formulation Mechanism of Productivity of Tropical Rain Forest Ecosystem and its Response on Climate Changes Category: Subsidiary Project of Major Research Project of CAS Chair Person: Zhang Jianhou (Professor) Caomin (Professor) Major Participants: Tang Jianwei, Sha Liqing, Zheng Zheng, Ma Youxin, Liu Wenjie Leading agency: Xishuangbanna Tropical Botanical Garden,CAS Time: 1998 ~ 2000 Objectives: Researches on formulation mechanism of productivity of tropical rain forest ecosystems and establish dynamic productivity model of tropical rain forest ecosystem in the area; provide data and model for assessing the present situation of production force in tropical forests in China and predict the trend of tropical rain forest productivity and determine the key factors influencing the productivity in tropical rain forest ecosystem. Major Contents: ?Process of nitrogen recycle in tropical rain forest ecosystems and the influence of environment factors on nitrogen recycling. ?Rules of soil nitrogen affecting tropical rain forest ecosystem production force. ?Photosynthesis and breathing rate of dominant species and the relationship between light, temperature, water and soil. ?Distribution process of photosynthesis products. ?Dynamics of tropical rain forest ecosystem litter layer and its decomposition process. ?Dynamics of moisture of tropical rain forest soil and the mechanism of moisture affecting ecosystem production force. ?Establishment of tropical rain forest ecosystem formulation and regeneration model. Research Results: Within 3 year s research work, the project revealed the nitrogen recycling and the influence of environment factors on nitrogen recycling in the tropical rain forest ecosystems and the rules of soil nitrogen affecting the ecosystem production force; still, the photosynthesis and breathing rate of dominant species, the distribution process of photosynthesis products and the relationship between light, temperature, water and soil are revealed; the project also finds out the soil moisture dynamics and its impact on production force and the litter layer decomposition process. The project also establishes tropical rain forest ecosystem formulation and regeneration module. On the conclusion of the project, 15 articles have been published, 4 of which are included into SCI catalog and 11 are included in CSCD in China. Key words: Tropical Rain Forest, Productivity, Climate Change Response, Model Research Fund 170,000 yuan 7 Project Name: Impact of Human Activities on C, N, S and P Recycling Dynamics in the Tropical Rain Forest Ecosystem Category: Special Support Project of the CAS Chair person: Han Xingguo Professor Major Participants: Tang Jianwei, Sha Liqing, Liu Wenjie, Yang Xiaodong, Zhang Guangming Leading agency: Xishuangbannan Tropical Botanical Garden, CAS Time: 1998 ~ 2000 Objectives: ?Explore the recycling mechanism of four elements: C, N, S and P in the tropical rain forest ecosystem and the interrelationships between these elements. ?Determine the distribution patterns of these elements in the ecosystems and the impact of slash and burning farming on these elements, especially on the reallocation losses of these elements. ?Use field experiments to study the sizes and sources of different groups of elements and determine the interaction mechanism between phosphorous recycling and carbon, nitrogen and sulfur recycling. ?Make use of CENTURY Model to reveal the long term impact of human factors (mainly slash-burning farming and single crop mode) on tropical forest ecosystem production force. ?determine the exploitation efficiency nutrients of dominant tree species and the rule of re-absorption. These researches will provide theoretical ground and practical guidance for ecological environment protection, land and forest resources uses and degraded ecosystem recovery. Major Contents ?Tropical rain forest ecosystem elements impulsive release; ?Impact of forest fire on nutrients and biological mass; ?Field and lab measurement, including biological mass on the ground and underground; ?Nutrient content dynamics; analysis on element content; ?CENTURY model rectification; Research Results Within 3 year s research, the project revealed the total amount of nutrient in the tropical rain forest ecosystems in Xishuangbanna; besides, it also described the impact of fire intensity on the release of carbon, nitrogen, sulfur and phosphorous volatilization and on the interaction mechanism between phosphorous recycling and carbon, nitrogen and sulfur recycling including mineralization rate of nitrogen, impact of the root system on the form and usability of phosphorous; impulsive release mechanism of nutrients in different ecosystems ; in addition, the project reveals the impact of slash and burn cultivation on the productivity in the long run. With the conclusion of the project, 11 papers were published and 2 doctoral and 4 master students were trained. Key words Tropical rain forest, element recycling, nutrient exploitation efficiency, slash and burn farming Research Fund 170,000 8 Project Name Research on Soil Seed Bank and Seed Rain in the Fragmented Tropical Rain Forest Category: Yunnan Youth Research Fund Chair Person: Tang Yong Assistant Professor Leading agency: Xishuangbanna Tropical Botanical Garden, CAS Participants: Zhang Jianhou, Dao Xiangsheng, Ren Yonghong Time 1997 ~2000 Objectives ?Obtain basic data of soil seed bank and seed rain in the fragmented tropical rain forest in Xishuangbanna; ?Reveal the impact of forest fragmentation on soil seed bank and seed rain; provide scientific evidence for tropical forest protection and recovery. Major Contents: ?Soil seedbank of fragmented tropical rain forests; ?Soil Seed rain of fragmented tropical rain forests; ?Relationships between soil seed bank, seed rain of fragmented tropical rain forests and the isolated vegetations nearby. ?Dynamic researches on the regenerated seedlings of fragmented tropical rain forests. Research Results ?This project studies the soil seed bank of the most typical fragmented tropical rain forest; the result of which shows that, in the soil layer of about 10cm deep, namely the rain forest of Chengzi which is isolated by secondary forests, the total soil seed bank is as high as 6494?55 pieces/m2, compared to that 4585?35 pieces /m2 of the successive rain forests. At the same time, Manyiguang rain forest fragment which is isolated by human plantations sees low amount of seed bank-3505?3 pieces/m2. These findings indicate that after rain forest being fragmented, because of the influence of separating vegetation, pioneering species invade and the seed bank increases; but when the separating vegetation is single species, the species and population of seed drops drastically for lack of sources of seed and this will affect the Succession of forests. ?The soil seed bank of fragmented tropical forests is determined by environment and plant reproduction conditions. It is strongly influenced by season changes in that the amount of seeds in the dry season is far more than that of rain season. The small the forest area, the bigger is the influence and the changes of soil seed bank are more obvious. ?Because of the influence of forest edge effect, the amount of seed at the edge of the forest is usually higher than the other part of the forests. This is the result of seed rain dissemination of separating vegetation. ?the input of seed rain of fragmented tropical rain forest is influenced by season changes. In the dry season, because of full blooming of pioneering species in the separating secondary forests, both the amount of seed input and species are at the climax. ?3 papers have been published in key national journals and 1 paper is presented at international symposium. Key words : tropical rain forest fragmentation, seed bank, seed rain Research Fund 46,000 9 Project Name: Research on Forest Opening Radiant Energy Environment Category: Yunnan Natural Science Fund Chair Person: Zhang Yiping Professor Leading agency: Xishuangbanna Tropical Botanical Garden,CAS Participants: Ma Youxin, Liu Yuhong, Li Yourong, Wang Jinxin Time: 1998 ~2001 Objectives: Reveal the rules of tropical forest openings and the changes of radiant energy in the adjacent areas; get to know the rules of forest opening radiant energy marginal effects, its radiant vicinity and the relationship with forest opening parameter and characteristics of leaves. Major Contents: ?Designate the tropical monsoon rain forests and secondary forest openings as study targets and carry out the following researches on the forest openings: ?Theoretical calculation. Use the methods of basin radiant and forest wall radiant calculation, plus forest opening parameter and leave characteristics to calculate forest openings of different sizes and shapes (round and oval) and the radiant energy distribution of forest edges at all directions different time and month. ?Calculation of radiant energy of forest openings and the adjacent areas. Carry out on-the-spot observations on designated forest openings on: a) radiation, and sunshine; b) temperature, moisture and surface temperature. ?Analysis on the characteristics of radiant energy of forest openings and adjacent areas. Results: ?the theoretical calculation of sun radiation of the forest wall at different months shows that the sunshine hours of forest wall in different directions of the forest edge are much less than the horizontal level, only the south and north sides enjoy the same sunshine as the horizontal level. ?the observation on the micro-climate factors of the forest opening in all directions shows that under the combined influence of regional weather conditions (such as fog), sun height and forest opening trees, the sunshine distributes asymmetrically in space. The region enjoy most sunshine is on northeast and north edge of the forest opening, which makes other micro-climate elements such as temperature, surface temperature and plant surface temperature distribute asymmetrically. This state of sunshine and temperature distribution imposes great impact on the distribution and growth of forest opening plants. ?The sunshine in the forest opening shows great differences as season changes and at different times of the day. ?Research on the sun radiation of different wavelength in the forest openings shows that the changes of sunshine at the center of the forest opening are determined by time and seasonal changes. At the early stages of forest openings and dry season, the radiation is the strongest, taking up a large proportion of the total sunshine. Of the radiation in forest opening, infrared radiation takes up a large percentage (>60%). ?Comparative analysis on distribution and the micro-climate factors such as tree surface temperature and ground temperature shows that apart from the known three heat function dimensions-canopy, ground inside forest and forest opening ground, there is a 4th heat function dimension the forest edge which is an important factor in forming forest opening heat effect and micro-climate in the forest opening. The micro-climate effect not only exists horizontally but also vertically and its function can not be ignored. Further studies on this is of great importance in getting overall understanding on forest edge environment heterogeneity biodiversity, and ecosystem structure and function. ?Observation on the continuity of atmosphere-plants-ground surface shows that because of influence of fog, sun height and forest opening edge trees, the heat transfer of the continuity of soil-plants-atmosphere changes according to time and season. Even at the same period of time, there is totally opposite heat transfer within different spots of the forest opening. These shows there exists a micro heat recycling within forest opening. ?Based on the research on the forest openings, the project carries out preliminary research on rubber tree plantation openings and subtropical broad evergreen leaves and the results are quite identical to what has been found in the tropical forests. ?7 papers have been published in key national journals, 8 papers have been presented at international meetings; the project also produced a master degree paper and 4 undergraduate papers and a chapter in academic book. Key words : forest gap, radiation, energy Research Fund 60,000 yuan 10 Project Name: Studies on the Micro-climate Edge Effect Mechanism of Tropical Forests Fragments Category: National Natural Science Fund Yunnan Province Natural Science Fund Chair person: Ma Youxin Professor Leading agencys: Xishuangbanna Tropical Botanical Garden, CAS Participants: Zhang Yiping, Liu Yuhong, Li Yourong Time: 1997 ~2000 Objectives: Reveal the atmospheric cycles at the edge of the forest fragments and describe the structure of atmospheric currents and wind fields; get to know the rules of marginal effects, the areas effected and the connections with forest edges and the changes of micro environment resulted from forest edge effect. Provide scientific evidence and strategy for tropical forest protection and management. Major contents: ?research on the characteristics of micro-climate on sample quadrant in and outside the forests. ?research on the relationship between micro-climate marginal effects and directions forest edge. ?Research on the characteristics of wind fields at the edge of the forest fragmentations. Research Results ?According to the horizontal and terraced observations on 3 tropical forest fragments and the micro-climate factors of a forest continuity the southward forest edge sees the biggest marginal effects, while the northward forest edge sees the smallest and edge on the east-west direction is in the middle. There is a temperature rising zone in within 10 meters of the southward forest edge because of strong sunlight, stable wind and heat accumulation. But other spots do not see this phenomenon. And this, this forest edge micro-climate effect can be used in planting tropical crops. This characteristics will strongly affect the distribution and ecosystem of species and the high temperature on the southward edge will increase forest fire hazards. ?The theodolite balancing and smoke technology are used to determine the atmosphere movement in the tropical forest and rubber tree plantation. Driven by the heat wave at the edge of forest, there is double circumfluence in canopy layer and the 2/3H H=forest edge height of the forest edge. The strength of the canopy layer is relatively low. The edge circumfluence of atmosphere guarantee the air exchange and satisfies the carbon and oxygen balance needed for photosynthesis while at the same time regulate the micro-climate and regional climate. ?researches on fragmented tropical rain forest at dry season and micro-climate of forest continuity of nature reserve of the same vegetation types show that as tropical rain forests being fragmented, the differences in of micro-climate in and outside the forest clearly diminish. The habitat in the forest turns drier and warmer and the buffer effect on climate outside the forest reduces. At the same time, because of the forest edge effect, the forest integrity is less compact and the biological heat potentials of the ecosystem reduce as well. ?Analysis on the micro-climate factors inside the forest and of the quadrant outside the forest shows that the depth of DEE at the northward edge is 15 m inside the forest while at the southward edge is 25 m. A review of the data obtained worldwide shows that the depth of biological and physical environment ranges from 10 m to 500 m with 100 m as the dominant depth pattern ( 87%). Under given DEE value and calculated with CAM, the round forest fragment is the least encroached by forest edge effect while the irregular and narrow shaped forest fragments are most affected. ?After forest being fragmented, it ability to regulate regional climate weakens. In the last 20 years, the average temperature in Xishuangbanna rises about 0.5 and this phenomenon is most felt during night time. The average rainfall drops by 100mm and humidity of air reduces by 1.4%; the total days with fog reduce by 14 days. ?The research finds that forest edge wall is an important heat function factor in forest edge heat effect and micro-climate formulation. ?4 papers have been published in key national journals, 2 are included in paper collections and 3 are presented at important national academic symposiums. Key Words: Tropical Forests, Fragmentation, Micro-climate, Edge effect Research Fund: 180,000 yuan 11 Project Name: Studies on the Tea Plantations Pests Communities and Natural Predators Category: Yunnan Provincial Fund Chair Person: Tao Tao Assistant Professor Leading agency: Xishuangbanna Tropical Botanical Garden Participants: Zhang Zhiying, She Yuping, Qing Di Time: 1995 ~ 1998 Objectives: Get to know the population, species, eating habits, preying methods and spatial distribution of pest insects of tea plantations; get to know the dynamic changes of the natural predators of these insect and the regenerating principles of these insects under the influence of human activities; provide pest control evidences and the way to use natural factors to suppress pests. Contents: ?Investigations on major pests and natural predators of tea plantations at the same age. ?Establish fixed observation sites in tea plantations located at different elevations and carry out seasonal investigations on pest communities and get to know the pests and predators at different periods of the year. ?Carry out seasonal investigations on pests and predator under different ecological conditions, getting to know changes on population and species. ?Analyze and compare pest communities, natural predator species, eating habits and distribtition in tea plantations of different ages. Results: ?In the six different ecological tea plantations in Simao, the dominant arthropod species are Acarina and collembola and altogether 3 species are commonly sighted, taking up 94.47% of all the captured arthropod from the soil. Thus, they constitute the basic element of soil arthropodin the tea plantations in Simao. ?There is not much difference of arthropodspecies distribution in tea plantations of different environments, of varied planting modes and ages, yet there are much difference in number and individual distribution patterns. Generally speaking, the richness of community of arthropodis positively related to organic matters, moisture and quantity of nitrogen. Of the 6 tea plantation habitats investigated, the plantations in high elevation and the aged plantations see the biggest amount of organic matters, so is the case with the number of anthropod. The number of arthropoddeclines downward vertically in the soil layer. Yet in the dry season (March), the bottom layers see more anthropod. ?In the 6 types of tea plantations, the diversity and evenness of soil arthropodis line with each other. Plantations with low production, less frequency of tea picking and fewer human activities see the biggest number of arthropodcommunities and evenness of distribution and vice versa. This shows that diversity of soil arthropodis determined by richness of communities and the even distribution of species. Human activities also impose some impact on the distribution of soil anthropod. ?4 papers published Key words: pest of tea plantations, community regeneration Research Fund: 50,000 yuan 12 Project Name: Community Structure of Small Beasts in Tropical Forests of Yunnan Category: Yunnan Provincial Applied Research Fund Chair Person: Wu Delin Professor Leading agency: Xishuangbanna Tropical Botanical Garden, CAS Participants: Fentyong, Yanxuchuan Time: 1995 ~1998 Objectives: Research and write academic papers on structure and hermits concerning small wildlife species communities in tropical rain forests in Yunnan; integrate knowledge in different fields to analyze the relationship between communities and habitats; compare the data of small wildlife species in tropical forests in other parts of the world and publish the findings in related journals. Contents: ?Select work sites according to different forest types. ?major investigations in each forest types are focused on the following habitats: micro-climate, vegetation types, litter layer and decayed wood. ?the community constituents, nutrition composition and the hermits of small wildlife species. ?richness of different small beast communities. ?biodiversity of different species and ecosystems. ?average density of different small beasts and estimation of biomass. ?food chains of different species and the their distribution. Results: ?In the tropical monsoon rain forest and mountain rain forest, Rattus niviventer is the dominant species and has the relative richness; Maxomys surifer is the secondary dominant species in the tropical monsoon rain forest. Two species of hole diggers are identified; there are 8 species of rodents and 9 species of chiroptera in the mountain rain forests; the number of the two wildlife in tropical rain forests is 7 and 11 species respectively. The dominant species are Callosciuru serythraeus, Callosciuru serythraeus zimmeensis Robinson et Wrougghton,Callosciurus pygerythrus and Tamiops macelellandi,Tamiops swinhoeihainanus and Hipposideros armiger. ?Species diversity and evenness of terrestrial wildlife in tropical seasonal rain forest is 1.21 and 0.55 in the monsoon rain forest is 1.01 and 0.49 while in the mountain rain forest is 0.89 and 0.39. ?The density of small wildlife species and biomass observation in tropical seasonal forest, tropical monsoon rain forest and mountain rain forest shows: density of small wildlife species: 11.33,22.11,14.36; biomass: 800.84 1304.60 and 792.42 There is no clear differences between density of terrestrial wildlife species and biomass. The project published a paper on SCI and another paper else where. Key words: tropical rainforest, small beasts, community structure Research Fund: 50,000 yuan