锡林郭勒盟草地物候期的时空演变及其对气候的响应

为揭示锡林郭勒盟草地的物候期变化趋势及其对气候因素的响应规律，基于2002-2014年的MODIS NDVI数据，采用双Logistics函数拟合和动态阈值相结合的方法提取了锡林郭勒盟草地的物候期，并对其时空演变特征及气候影响因素进行了分析和探讨。结果表明：（1）研究期内锡林郭勒盟草地返青期整体呈现提前趋势，枯黄期呈推迟趋势，生长期呈延长趋势。（2）研究区草地返青期与降水成显著负相关的面积占25.93%，与气温成显著负相关的面积占57.24%，与日照时数相关性不显著；草地枯黄期与气温呈显著负相关的面积占21.65%，与日照时数呈显著负相关的面积占22.24%，与降水的相关性不显著。

Spatio-temporal evolution of grassland phenology and its response to meteorological factors in Xilin Gol League

In order to reveal the trend of phenological period and the law of response to climatic factors in the grassland of Xilin Gol League, this paper extracted the phenological period of Xilin Gol League grassland by using the method of double logistic function fitting and dynamic threshold based on the MODIS-NDVI dataset from 2002 to 2014.This study investigated patterns of the spatiotemporal variations in phenology and its possible influence factors. The results show that:(1) During the research period, the grassland greenup of Xilin Gol League showed an early trend, the withering period showed a delayed trend, and the growth period showed an extended trend.(2)In the study area, 25.93% area of the Grassland greenup was negatively correlated with precipitation, 57.24% was negatively correlated with air temperature. Sunshine hours had no significant effect on the grassland greenup. 21.65% area of the Grassland withering period was negatively correlated with air temperature, 22.24% was negatively correlated with sunshine hours. Precipitation had no significant effect on the grassland withering period.