Abstract: Aerjin (Altun) Mountain National Nature Reserve is one of three refuges for rare and endangered ungulates such as Tibetan antelope in QinghaiTibetan Plateau. As a kind of migration ungulate, Tibetan antelope’s population could be effectively protected through identifying its habitat suitability in cold (January) and warm (July) seasons. On the basis of niche theory, we used GIS and AHP jointly to build a GISbased niche model for delimiting and classifying habitat suitability in cold and warm seasons. Results showed that total areas of high suitability and moderate suitability habitats in cold and warm seasons were 12620 and 15630 km², respectively. High suitability habitats in cold and warm seasons were located in the northeast of the reserve (the northeast of Kumkury Desert), the middle of the reserve (from Kardun inspection station to the eastern boundary of Aqqikkol Lake) and the southwest of the reserve (near Tuzihu inspection station). Moderate suitability habitats were located in the southeast of the reserve and around the high suitability habitats. The total areas of low suitability habitats were 9930 km² in cold season and 8400 km² in warm season. Low suitability habitats were located between moderate suitability habitats and unsuitable areas in cold season, and around Jingyu Lake and moderate suitability habitats in warm season. Unsuitable areas in cold and warm seasons were 24290 and 22810 km², respectively, and were consisted of the north of reserve, lakes, desert, and high elevation zone. Our study indicated that habitat suitability differed in cold and warm seasons. The distribution of Tibetan antelope was predominantly limited by natural and anthropogenic factors in cold season. The distributions of Tibetan antelope were more concentrative in cold season, but more dispersive in warm season.

Key words: root length, root surface area, yield, tillage practice