关键词: 气温, 降水, 植物物候, 植被盖度, 纯盖度, 民勤荒漠区

Abstract: Based on the phenological data in 1974-2009 and the  plot vegetation data  in 2002-2010 as well as the meteorological data, this paper analyzed the responses of the vegetations in Minqin desert area to climate change. In 1961-2010, the air temperature and air humidity in the study area increased, and the increasing rate of the mean annual air temperature was greater than the global level and China’s level over the past century. The responses of the vegetations to the air temperature change were mainly manifested in the advance of spring phenology, delay of autumn phenology, and lengthening of growing duration, whereas the responses of the vegetations to precipitation change were mainly manifested in the decrease of vegetation coverage and pure coverage with the decreasing precipitation. The plant density and richness fluctuated with the variation of precipitation, and the vegetation coverage and pure coverage were positively correlated with the annual precipitation firstly, and the precipitation in Jun-July and in April-May secondly. The plant density and richness were positively correlated with the precipitation in September. The advance of the spring phenology was in the order of bud-expansion > budopening > beginning of flowering > beginning of leaf-extension and leaf flourish > flower-bud appearance > flower flourishing > end of flowering > fruitmaturity, whereas the delay of autumn phenology was in the order of full leaf-discoloration > beginning of leaf-fall > beginning of leafdiscoloration > end of leaf-fall. As compared with the increase of air temperature in autumn, the increase of air temperature in spring had greater effects on the plant phenology in Minqin desert area.

Key words: air temperature, precipitation, plant phenology, vegetation coverage, pure coverage, Minqin desert area.