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-economic-climate-impact model combined with seven general circulation models (GCMs). These climate change scenarios show that annual mean temperatures might increase by about 1.4 degrees C, and annual total precipitation might increase by about 4% over the whole of China in comparison with the present climate. The change in precipitation might be much smaller 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 seven GCMs for 2050. All scenarios suggest a large change in natural vegetation, although details of predicted types vary between the scenarios. There will be a northward shift of vegetation types, with an increase in the areal extent of tropical rain forests and decrease of cold temperate coniferous forest and tundra. China has a high population. During the historic development of several thousand years large areas of forest and grassland have been converted into arable lands; at present agriculture is a very important element of vegetation cover. Consequently, considering all these changes and situations, especially in combination with the probable negative balance between precipitation and evapotranspiration (that is, increase of moisture stress) the possible influences of climate change on Chinese a agriculture are assessed briefly in this paper. As a result of the above-described analyses it is extremely difficult to draw general conclusions of the potential implications of climate change for Chinese vegetation because of scientific uncertainties both of investigation of climate change and of its vegetation response.