关键词: 高寒草原, 气候变化, 降水量, 蒸发量, 畜牧业, 西藏

Abstract: Temperature in northwest Tibet was increased significantly, especially in dry season, precipitation was increased in most areas, but the potential evaporation was decreased during the period from 1971 to 2010. Regionally, temperature was increased significantly, precipitation was increased, potential evaporation was decreased in the central and eastern parts of northwest Tibet, and climate trended a warmingwetting pattern. However, temperature was increased, precipitation was decreased, potential evaporation was increased, and climate trended a warmingdrying pattern in the western regions including Shiquanhe. The beginning time of pasture growing and greengrass seasons became earlier, their end time was postponed, the durations were extended significantly, and the cumulative temperature and precipitation were increased significantly in these seasons. The fatten duration of livestock were extended significantly in most places 〔the tendency rate was 2.7 d•(10a) ^-1〕, and the fatloss duration was in a significant reduction 〔the tendency rate was 6.1 d•(10a)^-1〕 in northwest Tibet in recent 35 years. Climate change was in a favorable trend for steppe animal husbandry in the northwest Tibet. It is of significance for controlling steppe degeneration to rationally regulate the livestock structure and limit the number of livestock, especially goats in northwest Tibet.

Key words: alpine steppe, climate change, precipitation, potential evaporation, animal husbandry, Tibet