IMPACT OF CLIMATE-CHANGE ON NATURAL VEGETATION IN CHINA AND ITS IMPLICATION FOR AGRICULTURE

Climate change scenarios due to human activity in East Asia and China by 2050 have been estimated by means of a simple global social-economi c-climate-impact model combined with seven general circulation models (GCMs). These climate change scenarios show that annual mean temperatu res might increase by about 1.4 degrees C, and annual total precipitat ion might increase by about 4% over the whole of China in comparison w ith the present climate. The change in precipitation might be much sma ller than that of temperature. The potential impacts of human activity -induced climate change on natural vegetation in China were estimated using the vegetation-climate model developed particularly for Chinese vegetation types and different climate change scenarios derived from s even GCMs for 2050. All scenarios suggest a large change in natural ve getation, although details of predicted types vary between the scenari os. There will be a northward shift of vegetation types, with an incre ase in the areal extent of tropical rain forests and decrease of cold temperate coniferous forest and tundra. China has a high population. D uring the historic development of several thousand years large areas o f forest and grassland have been converted into arable lands; at prese nt agriculture is a very important element of vegetation cover. Conseq uently, considering all these changes and situations, especially in co mbination with the probable negative balance between precipitation and evapotranspiration (that is, increase of moisture stress) the possibl e influences of climate change on Chinese a agriculture are assessed b riefly in this paper. As a result of the above-described analyses it i s extremely difficult to draw general conclusions of the potential imp lications of climate change for Chinese vegetation because of scientif ic uncertainties both of investigation of climate change and of its ve getation response.