Characterics Of Spatio-ternporal Distribution Of Global And Rcgional Vegetation Types Based On CSCS Model

Bioclimatology based vegetation classification models play an important role in studying the response of terrestrial ecosystems to global warming. On the basis of validation for classification accuracy of Potential Natural Vegetation (PNV) types simulated by the Comprehensive and Sequential Classification System (CSCS) model, using the global sharing meteorological databases and GIS spatial analysis approach, this study analyzed the spatio-temporal distribution patterns, change rules and the succession tendency of PNV types in the global and regional scales in the past100years (1901-2000) and the future50years (2001-2050); Taking China as an example, the distribution of remained PNV types and its typical areas, as well as the application of CSCS theory in monitoring and evaluating the growth condition of existing vegetation were studied; Ultimately, on the basis of the main results of this study, the global PNV management system based on CSCS model was developed.The results are as follows:1) On a global scale there are good agreements among maps produced by the CSCS method and the globally well-accepted Ramankutty&Foley PNV (RF PNV), Holdridge Life Zone (HLZ) and BIOME4PNV models. Comparing with HLZ, the CSCS model can not only predict the spatial distribution extent of tundra, desert and forest, but also identify grassland vegetation types preferably.2) Based on CSCS model,10broad vegetation categories and42classes of the potential vegetation can be identified at global scale excluding Antarctica, the area of global PNV excluding regions of permanent snow/ice cover and inland water is1.289335×108km2, which covers96.07%of the total land area of Earth. In China there are10broad vegetation categories and40classes excluding subtropical extrarid subtropical desert and tropical extrarid tropical desert. There is significant difference between the existing vegetation and PNV due to the influence of human activities. According to the magnitude of human influence in ascending order, the PNV types are tundra, desert, forest, shrubland and grassland, respectively.3) During the period of past100years, excluding the warm desert and savanna, the shift direction of the rest of8broad vegetation categories are different in the northern and southern hemispheres. The shift distance of the warm desert in the southern hemisphere was the largest among the10broad vegetation categories. Except for tundra&alpine steppe, subtropical forest and temperate humid grassland, the shift distances in the southern hemisphere for the rest of7broad PNV categories were larger than that in the northern hemisphere.4) The global land temperature has an increasing trend in future50years, especially in the northern hemisphere. The variation of global precipitation has no distinct regional regulation. Overall, the global climate would be warming and drying, but warming and humid in local area. In China, the temperature rising range would be during1.5-4.5℃and precipitation would be distinctly increasing in south and decreasing in north over the next50years. In future (i.e., by the end of the year2050), the area of global potential tundra would be decreasing rapidly, while the area of potential desert and grassland would be increasing, and the area of potential forest would be slightly increasing; the change tendency of the potential vegetation area in China is similar to that in global scale, but different in area change magnitude.5) The area of remained PNV types is624.7089×104km2in China, accounting for65.07%of total land area. The area of remained PNV typical area account for16.13%and9.65%of total remained PNV area and total land area, respectively. The typical area is mainly distributed in the southwestern and the western regions with the sparsely populated, high altitude and complex terrain. There is no typical area of remained PNV types in northeastern, northern and central areas of China, and rare distributed in southern and coastal area.6) It would be warming and drying in the west, and warming and humid in the most of eastern areas in the Qinghai-Tibet Plateau (QTP) in the future (i.e., by the end of the year2050), and the warm desert would appear in the period2001-2050. In the future, the area of forest in the QTP region would be increasing significantly, and the increasing rate reaches125%. However, the area of grassland (including tundra&alpine steppe, frigid desert, semi-desert, temperate humid grassland and steppe) would have an obvious decreasing trend, and the decreasing rate is25%. Because of affected significantly by temperature rise and precipitation redistribution, the area of tundra&alpine steppe would be reducing severely, almost56.82%area would be decreasing in the future.7) On the basis of existed studies, the system structure, data organization and system function design, the global PNV management system website was designed and developed by use of ArcGIS Server and Flex framework.