吕梁山地区植被物候变化及对气候的响应

吕梁山地区地形垂直差异明显,植被对气候变化反应敏感,研究吕梁山地区植被物候变化,探索植被物候变化与气候的响应关系,旨在为高海拔山区植被物候研究和生态治理提供借鉴。基于2000—2015年MODIS NDVI时间序列数据,通过动态阈值法提取吕梁山地区的植被物候,对气温、降水进行空间插值,并对植被2个关键物候期与气候因素进行偏相关分析。结果表明：（1）植被生长季开始日期(the start of the growing season,SOS)提前的区域约占85.7%,其中16.2%显著提前;植被生长季结束日期(the end of the growing season,EOS)推迟的区域约占90.6%,其中33.3%显著推迟。（2）区内74.8%、87.7%植被SOS分别与气温、降水呈负相关,气温升高或降水增加,植被SOS提前。植被SOS在高海拔山区受4月气温影响显著,而低海拔地区受4月降水影响显著。（3）区内72.6%、65.1%植被EOS分别与气温、降水呈正相关,气温升高或降水增加,植被EOS推迟。植被EOS在北部和西部地区受11月气温影响显著,而高海拔地区受9月降水影响显著。2000—2015年吕梁山地区植被物候发生显著变化,各地区对气温、降水的响应不同,研究结果可为区域物候、气候变化研究和陆地生态治理提供科学依据。

Changes of Vegetation Phenology and Its Response to Climate in Lvliang Mountain Area

The vertical difference of the topography in the Lvliang Mountain area is obvious, and the vegetation is sensitive to climate change. By studying the vegetation phenology change in the Lvliang Mountain area and exploring the response relationship between the vegetation phenology change and the climate, the research can provide reference for vegetation phenology research and ecological management in high altitude mountainous areas. Based on the MODIS NDVI time series data from 2000 to 2015, the vegetation phenology of the Lvliang Mountain area was extracted by dynamic threshold method and the temperature and precipitation were spatially interpolated and then the two key vegetation phenology periods and climatic factors were analyzed for partial correlation. The results showed that: (1) the region with the advanced vegetation SOS accounted for about 85.7%, of which 16.2% was significantly advanced; the region with the delayed vegetation EOS accounted for about 90.6%, of which 33.3% was significantly delayed; (2) the vegetation SOS in 74.8% of the region and 87.7% of the region was negatively related to temperature and precipitation respectively, as the temperature rose or the precipitation increased, the vegetation SOS advanced; vegetation SOS was significantly affected by temperature in April in high-altitude mountainous areas, while by precipitation in April in low-altitude areas; (3) the vegetation EOS in 72.6% of the region and 65.1% of the region was positively related to temperature and precipitation respectively; as temperature rose or precipitation increased, vegetation EOS was delayed; the vegetation EOS in the northern and western regions was significantly affected by the temperature in November while in high-altitude mountainous areas by precipitation in September. From 2000 to 2015, the vegetation phenology in the Lvliang Mountain area changed significantly, and each region had different responses to temperature and precipitation. This study can provide a scientific basis for regional phenology and climate change research and terrestrial ecological management.