关键词: 动物啃食, 气候变化, 影响与适应, 草地退化, 政策评估

Abstract: This paper focus on climate change adaptation, land use management and grazing strategies in Alxa League, Inner Mongolia, China by use of social survey, statistical analysis and numerical modeling. Results suggest that the climate change adaptation must keep a balance between sustainable development of local economics and ecological system. Our investigation shows that grazing ban and ecological migration are two major adaptation strategies in Alxa League. Grazing ban has led to a quick regeneration of local steppe on the one hand, and on the other hand the migration has enhanced pressure on emigrant towns. For instance, increase of population in the towns of over-cultivation has caused land degradation around the towns, and over-use of deep ground water has made ground water drop and surface soil salinization. The grazing ban has also led to a series of negative effects, such as increase in mouse population and fire risk due to accumulation of dry matter, and the final decrease of biological diversity although there is an initial increase since grazing ban. Some local shrubs degrade without grazing, showing that a certain extent grazing can maintain the ecological balance of stepepe. It turns out that ungulate plays an important role in the ecological system of the west Inner Mongolia. To quantitatively investigate the grazing effect, we made a numerical simulation of local grassland NPP (Net Primary Production) under different grazing pressures with a forest dynamical model (FORSPACE), which incorporated ungulate grazing, wild fire, hydrological process, ecological system, and climate change. It confirmed that suitable grazing or controllable grazing would be not only in favorable to vegetation growth in dry land, especially to local shrubs, but also alternated in reducing the pressure of the emigrant towns and increase the income of local residents. By contrast, over grazing would destroy surface vegetation and lead to animal death. So local adaptation policy modification is proposed to allow some extent grazing, and encourage enclosed economical animals feeding. The policy should combine both local economic development and ecological conservation under global warming background.

Key words: ungulate grazing, climate change, impact and adaptation, grassland degradation, policy assessment