Main Research Achievements During the Latest Five Years Dinghushan Forest Ecosystem Research Station (Dinghushan station in brief) was directly affiliated to South China Institute of Botany, Chinese Academy of Sciences. The station focused on natural forest ecosystems in south subtropical China, including monsoon evergreen broadleaved forest (the zonal vegetation type), mixed broadleaved and coniferous forest, and pine forest at the horizontal level, and ravine forest, river bank forest, monsoon evergreen broadleaved forest and mountain evergreen forest from low to high altitude. Our overall goal is to strengthen our understanding of the structures, succession dynamics of these forest ecosystems as well as their functions and services in mass and energy flow, gas exchange and nutrient cycling, interactions among these processes, as a basis for advancing our ability to describe the role of these forests in regional and global scales and providing guidance for forest management, theoretically and practically. During the latest five years, we had received 25 projects, which were supported mainly by the National Natural Science Foundation, the Chinese Academy of Sciences, and Local foundations such as Guangdong provincial NSF and provincial EPA. Some programs were funded by international organizations such as Rockefellor in USA and Keidanran in Japan. Brilliant achievements have been made, part of which have been approved by scientists and experts, and granted awards by governmental or scientific associations. These awards include first prize in national science and technology progress, first prize in science and technology progress of CAS, first and second prize in natural science of Guangdong province. During this period, four books have been published, and 150 papers published in the referred national and international journals, among which 10 papers referred in SCI. Our major activities were described as followings: 1. A number of research activities have been carried out in our station, covering the kinetic energy of rainfall, kinetics of rain drops in canopy throughfall, the interaction between the kinetic energy of atmospheric rainfall and kinetic energy of rain drops in throughfall and their impacts on soil surface erosion. Based on the results obtained from studies on restoration process of degraded ecosystems in this region, we concluded that we should not only consider the survival of the pioneer species and its impacts on soil quality, but also be aware of the rainfall impacts on soil erosion, when we choose the pioneer species. This achievement was come out of the project “The effect of forest canopy on the soil surface erosion from raindrops” which was funded by natural science foundation of Guangdong province(1997~1999, ¥150,000 yuan) and state natural science foundation(1998~2000, ¥200,000 yuan), and was taken charge by principal researcher ZHOU Guo-yi (gyzhou@scib.ac.cn, Tel: 020-85231708; Fax: 020-85232615 in South China Institute of Botany, CAS). 2 The theory of limited factors of the south subtropical degraded ecosystems in the course of their restoration were brought forward. We found that the imparity of water-heat environment among seasons would result in enhancing the potential soil erosion of the degraded ecosystem during rainy season and adverse habitat because of the high temperature and less rain during the dry season. All of these can limit the efficiency of the degraded ecosystems’ restoration. One of puzzled problems in the academia is why the climax vegetation was very difficult to restore once destroyed. This was partly clarified functionally by our investigations on (1) Restoration process and coupling of time and space in the tropical and subtropical degraded ecosystem (1997-2000,￥200,000 yuan), special support fund from CAS, headed by principal researcher ZHOU Guo-yi (gyzhou@scib.ac.cn; Tel: 020-85231708; Fax: 020-85232615); and (2) The restoration of the south subtropical pine forest ecosystem, a Sino-American cooperation project(1997-2000, USD ＄50,000), led by principal researcher MO Jiang-ming, and participated by associate researcher YAN Jun-hua and associate researcher ZHANG De-qiang. 3 Based on the integrated results from aspects of water balance, energy flow and nutrient cycling, we concluded that the regional forest ecosystems in subtropical area have both characteristics of a great stability and a potential frangibility, therefore, it provided an opportunity for us to discuss the problem of the formation mechanisms of these regional forests in Dinghushan reserve, and address the problem why the climax vegetation in subtropical area was hard to restore after a serious destruction. We found that nutrition was stored mainly in plant instead of in soil. Thus, if the vegetation was destroyed entirely, much nutrition would be removed by soil and water processes. Additionally, soil profiles were thinner in most part of this region, together with a serious soil acidification and uneven distribution patterns of heat and water, all of this enhanced the difficulty for vegetation restoration. Several projects had involved with this work: (1) The study on the formation mechanisms of Dinghushan forest ecosystems(1999-2001, ￥200,000 yuan), a Sino-Japanese cooperative program, headed by ZHOU Guo-yi (gyzhou@scib.ac.cn; Tel: 020-85231708;Fax: 020-85232615); (2) Study on the nutrient concentration in rainfall, throughfall and stemflow of selected forests in Dinghushan reserve(1998-2000, ￥50,000 yuan), headed by by ZHANG De-qiang（zhangdeq@scib.ac.cn; Tel/fax: 020-85232615）; (3) Photosynthesis control of subtropical forest trees along a light gradient(1998-2000, ￥50,000 yuan), headed by PENG Chang-lian (pengchl@scib.ac.cn; Tel/fax: 020-85232615); (4) Sensitive analysis on forest plants and soils affected by acid precipitation and strategies for rehabilitation(1999-2002, ￥260,000 yuan), jointly funded by Guangdong provincial NFS and EPA, and headed by Wen Dazhi(dzwen@scib.ac.cn; Tel/fax: 020-85232615). All these projects were participated by the staff at Dinghushan station.