中国东部植被物候变化及其对气候的响应

Detecting Vegetation Phenological Changes in Response to Climate in Eastern China

  • 摘要: 使用1982—2006年的GIMMS NDVI数据,基于TIMESAT程序,提取并分析了中国东部不同土地利用类型植被的物候(生长开始期、生长结束期和生长季长度)变化特征及其对气候的响应。获得以下结论:(1)各土地类型植被的NDVI变化都具有明显的季节规律。自然植被的NDVI年变化曲线表现出显著的单峰型。而农业植被的NDVI年变化曲线表现出双峰,第一个峰值一般出现在5月份,第二个峰值大约出现在8月份;(2)农业植被的生长开始期一般要早于自然植被;(3)1982—2006年间,林地的生长季长度延长了11.3d·(10a)-1;草地的生长开始期提前了6.4d·(10a)-1,生长季长度延长了7.2d·(10a)-1;有灌溉旱地的生长开始期提前了5.8d·(10a)-1,生长结束期提前了11.6d·(10a)-1。引起植被物候发生显著变化的主要气候因素是气温,降水的作用不明显。

     

    Abstract: In this study, the software TIMESAT was used to generate smooth time series of GIMMS NDVI as well as to estimate the vegetation phenological parameters for eastern China from 1982 to 2006. Results show that the significant positive trends were observed for the length of the growing season for the forest land and grassland. The start of the growing season (SGS) has been advanced for the grassland and irrigated cropland, and the end of the growing season has also been moved up for the irrigated cropland. The temperature plays a key role in influencing these phenological changes for different vegetation types, while the effect of precipitation is obviously not observed. For example, the SGS for the grassland correlates strongly with the temperature of the preceding month (March) of the SGS, and the SGS for the irrigated cropland is greatly affected by the temperature of the month (February) of the SGS.

     

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