中文摘要：

将不同函数方法拟合后的植被指数时间序列数据比较，选出最佳拟合方法拟合了锡林郭勒盟典型草原1990--2008年中14a的物候期和生长季长度，研究它们的时空变异规律．结果表明：1）返青期和枯黄期在空间上大体呈现从锡林郭勒盟东北到西南地区逐渐推后的趋势，在时间上，不同年份草原物候期变化程度不同；2）拟合锡林郭勒盟典型草原14a的平均物候期和生长季长度，发现返青期、枯黄期、生长季长度分别集中在110-150、300-320、190-200d，分别为提前、提前、缩短的趋势占优势；3）7年返青期观测值与拟合值差值平均值约为～4d，总体拟合效果较好．

英文摘要：

Different vegetation index timing curves were compared to choose the best fit for phenological phase and length of vegetation season from 1990 to 2008 and to analyze temporalspatial characteristics. The beginning and ending of vegetation season were found to show gradual delays from Southwest to Northeast regions, with some variations in different years. Fitted typical grassland average phenophase and length of vegetation season in Xilingole indicated that beginning of vegetation season still showed delays from Southwest to Northeast regions. The beginning and ending of vegetation season and length of vegetation season was concentrated in 110-150 days, 300-320 days and 190-200 days respectively, variations were advanced, advanced and shortened respectively. The difference of measured and fitted values for the beginning of vegetation season in the seven year study period was --4 days with very good overall fit.