Abstract:

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.

Key words: vegetation phenology, dynamic threshold, partial correlation, climate response, Lvliang Mountain