Vegetation phenology dynamic and its responses to meteorological factor changes in the Mu Us Desert of northern China

ObjectiveMonitoring regional vegetation phenology in sand area and determining the relations between vegetation phenology and meteorological factors are crucial to understand the dynamic response of sand area ecosystem to climate change.

MethodIn this study, through normalized difference vegetation index (NDVI) time series data, we extracted vegetation phenology by Polyfit-Maximum method, and analyzed the trends and relationships between vegetation phenology and climatic factors (air temperature and precipitation) in the Mu Us Desert of northern China over the past three decades (1982-2015).

ResultIn the Mu Us Desert, The beginning date of growing season concentrated in the 96th-144th day, the ending date of growing season concentrated in the 280th-300th day, and the length of growing season ranged in 135-195 days. From east to west, the beginning date of growing season postponed gradually and growing season length shortened gradually, while there was no obvious change in the ending date of growing season. In the past 34 years, the beginning date and length of growing season for vegetation in the Mu Us Desert showed significantly advanced and prolonged trend, and the changing rates were 0.54 day/year and 0.94 day/year, respectively. While the ending date of growing season showed postponed trend but not delayed obviously. The beginning date of growing season for vegetation in the Mu Us Desert was mainly affected by the mean air temperature from February to April, and its ending date was mainly affected by the accumulated precipitation from August to October.

ConclusionThe vegetation phenology characteristics have changed significantly in Mu Us Desert, which was mainly reflected in the advancement and extension of growing season. This will promote the vegetation restoration and desertification reversion in the study area.