The Effect Of Climate Change On The Structure Of Forest Ecosystem In China’s Southern Red Soil Hilly Region

The natural environment and human social life has been effected by the global climate change for centuries. As one of the most important part on the earth, the forest ecosystems affected by global climate and land use change is relatively obvious. At the same time, the mechanism of forest ecosystem response to global climate change is also gradually attaches to the people. In order to explore the effect of global climate change on the structure and function of forest ecosystem in China’s southern red soil hilly region at regional scale. It not only has great theoretical significance for the regional scale of research on the influence and response of global change, but the results to the optimization and upgrade of different forest ecosystem structure has important practical significance.In this paper, we choose the climate change impact on forest ecological system as our research perspective, and we choose TaiHe county of JiangXi province as our study area. Forest Landscape models are used as the combinated methods, tree species-gap-landscape forest system models, as the core of our study. PnET-Ⅱ, LANDIS-II and APACK are utilized for simulating the response of25kinds of trees to the climate change under different climate emission scenarios from2010to2100year. The data of Representative Concentration Pathways are used in this paper as our different climate emission scneatios in the future.Study of climate change on forest ecosystem structure and function have been divided by three parts. The structure is including the structure of the tree species, the structure of the age and the structure of the landscape. The function is including ANPP (Aboveground Net Primary Productivity) and biomass. There are some conclusion as follows:1) We believe that ANPP and SEP can well reflect the response to climate change. And then, we treat them as the important impact factors that can influence the structure and function of the forest ecosystem.2) Only considering the effects of climate change, have the25species’ANPP, SEP and total biomass in the forest great change under different climate emission scenarios from2010to2100. To begin with, there is a little difference individual among the ANPP, SEP and biomass value for the different tree species in RCP2.6and RCP4.5scenario. However, the value of the ANPP, SEP and biomass for different species change relatively bigger in RCP8.5scenario. The simulated value of more than90%tree species is obviously lower than that in RCP2.6and RCP4.5scenario simulation values. As a result, we think in RCP2.6climate emissions scenario will be more beneficial to the development and content of forest ecological function in TaiHe county. In RCP4.5emissions scenario, the impact on the content of the function is a bit poor comparatively, and RCP8.5scenario will not conducive to content of forest ecosystem structure and function development.3) For the structure of different age class, some overmature forest area, such as Cunninghamia lanceolata, Pinus elliottii, Schima superb and Pinus massoniana, cover most part of the study area, while other age class accounts for a smaller.4) Under the condition of without considering other disturbances, forest age class structure in the natural succession process tends to complicate, diversity index increased from0.773to1.651and the dominance index decreased to0.429from0.648. With increasing the whole landscape fragmentation, the patches shape tend to be simple the patches number of the forest landscape keep increasing, average patch perimeter area ratio index value decreased from1.835to1.387, spread degree index fell to0.621from0.78, so as the coverage rate of the forest.