关键词: 东北农田, 空间过程, 功能类群, 节肢动物, 生物多样性

Abstract: Alpine desert grassland dynamics is important for global change study. As one of the four largest “noman lands” in China, Altun Mountain National Nature Reserve is facing alpine desert grassland ecosystem changes, which may have a tremendous impact on the habitats of wild animals. Especially, the landscape along the rive corridor could be greatly affected by climate change. Based on GIS and RS technology, we selected a typical river corridor in Aya Lake Basin as the case study site and classified the landscape types using remote sensing data in 1990, 2001 and 2007. Taking advantages of landscape theories and methods, we analyzed the landscape pattern and dynamics in the region. The results showed that the areas of both water and salinealkali lands in the region increased significantly, while the grasslands with different coverage degraded due to the conversion into other land uses. The integrated pattern of landscape changed greatly. Patch density and landscape diversity index increased, while the landscape shape became simple. Largest patch index increased and the splitting index decreased. The increases of water area and salinealkali land with grassland degradation caused the decrease of the NDVI values. Climate change trend analysis suggested that the increases in precipitation and temperature were the major driving forces for the landscape change in the region. The rise of the lake water area changed the distribution of the swamp, leading to the increase of water table and the increase of soil salinization.

Key words: functional group, spatial process, arthropods, biological diversity, cropland in Northeast China