Impacts Of Climate On Spatiotemporal Variations In Vegetation NDVI In Inner Mongolia

Vegetation plays a very important role in the material cycle of terrestrial ecosystems.This study is based on the third generation of NDVI from the Global Inventory Modeling and Mapping Studies,supplemented by Piecewise Linear Regression Analysis,One-dimensional Linear Regression Analysis,and Rescaled Range Analysis(R/S),Correlation Analysis and Partial Correlation Analysis,combined with Variational Mode Decomposition,explored the spatio-temporal changes of vegetation to response to temperature and precipitation in different regions of Inner Mongolia from 1982 to 2015.The main findings of this study are as follows:(1)Temperature and NDVI showed a slow growth trend from 1982 to 2015,and the precipitation showed no significant slow decline;the vegetation NDVI increased slowly from 1982 to 1999,the grassland degradation and land desertification were serious during 1999-2009.And the vegetation in Inner Mongolia has gradually improved.(2)Temperature and precipitation were important factors that affect the dynamic changes of vegetation in different areas of Inner Mongolia Grassland.During the growing season from 1982-2015,NDVI and temperature had a major change cycle of 7 months and 3.5 months,with the same change cycle of precipitation only 7 months.(3)The NDVI time series had a significant hysteresis effect on average temperature and precipitation for 6~8,10~11,18~20 and 23 months.When the lag period was June,October-November,the average temperature and precipitation had a significant positive driving effect on vegetation growth.The lag period was 19-20 months,and the average temperature and precipitation on the vegetation grew very much.What is more,the vegetation responded more strongly to precipitation,and the temperature was too high or too low to inhibit vegetation growth.The above findings suggest that wise decisions can be made in grassland management as an important reference for grassland managers or decision makers.