Analysis On Spatial And Temporal Distribution Patterns And Driving Forces Of Grassland In Xinjiang

Grasslands serve as an important ecological barrier,and research on grassland is of great significance to ensure local ecological protection and economic development.This study used data such as land use/cover change(LUCC),normalized difference vegetation index(NDVI),vegetation’s net primary productivity(NPP),digital elevation model(DEM),different meteorological factors,and socio-economic data.By using unary linear regression analysis,correlation analysis,land use transfer matrix,net ecosystem exchange(NEE)rate,topographic position index(TPI),and other methods,through the combination of point and surface methods in the whole Xinjiang grassland,desert grassland(an important part of Xinjiang grassland and affected by relatively less human activities)and grassland on the northern slope of Tianshan Mountains(human activities in the study area have a greater impact),we analyzed the temporal and spatial distribution and its driving forces of grasslands in Xinjiang region.We determined the area and the range of grassland coverage for each period in Xinjiang through LUCC,analyzed the conversion of grassland and other land-use types using the land use transfer matrix,and also evaluated the impact of human activities on the grasslands by combining statistical data.The range of desert grasslands was determined,and their distribution and area changes were studied.In the current study,we examined the quality change in Xinjiang grasslands through NDVI and NPP datasets and assessed the response of Xinjiang grassland to climate change based on meteorological factors.Overall,the following can be concluded:1.Grassland(except the unused land)is the largest land-use type in the Xinjiang region.The maximum area was covered by the low-coverage grasslands,which are dominant in southern Xinjiang grassland.The productivity of grassland in northern Xinjiang is higher than that in southern Xinjiang.2.Significant correlation exists between topography and factors such as the spatial distribution of grassland in each coverage,the spatial distribution of different meteorological factors,and the range of human activities.The distribution of grassland in Xinjiang is primarily determined by natural conditions.3.During the study period,there was an overall trend of first increase and then decrease in the total grassland area and the area of high,medium,and low coverage grasslands in Xinjiang.The NDVI of high-,medium-,and low coverage grassland showed an increasing trend;NDVI of high coverage grassland showed the highest increase in the area;NPP fluctuated and showed a slight downward trend.4.The change in grassland in Xinjiang is the outcome of climate change and human activities;climate change is the main reason for the variation,and a decrease in grassland productivity and human activities are the principal reasons for bringing about drastic changes in land use types and patterns in a short period.