Abstract:

Based on multi-source remote sensing data， including NDVI， NPP， CLCD， topographic slope， and derived ecological characteristic parameters （NDVI_S and CV） from 2013 to 2022， this study constructs an ecological characteristic coupling system incorporating NPP， CV， NDVI_S， and land use transfer matrices to conduct functional zoning of the Horqin Sandy Land ecosystem. The results indicate that： The conservation zone covers an area of 4 435.3 km²， predominantly forest （91.7%）， concentrated in the southern foothills of the Greater Khingan Mountains and the northern hilly areas of the Nurulhushan Mountains， with water bodies and wetlands mainly distributed in reservoir and marsh areas. The stable zone spans 59 471.3 km²， primarily consisting of farmland （62.6%） and grassland （35.4%）. Farmland is concentrated in the central， eastern， and southern parts of the sandy land， while grassland is predominantly distributed in the northern region. The restoration zone covers 27 979.8 km²， mainly grassland （97.2%）. Except for the eastern and southern regions， the areas along the Xiliao River dominated by agriculture， and the northern forest conservation zone， other areas show a marked reversal trend. The degradation zone occupies 22 731.8 km²， with mild degradation being predominant （18 483.5 km²）， concentrated in the eastern and southern farmlands and the southern foothills of the Greater Khingan Mountains in the north. The conversion of farmland and grassland to low vegetation cover land uses is most active， and severe degradation of water bodies is observed in the northwestern part of Tongyu County. The ecologically fragile zone covers 8 472.2 km²， dominated by impervious surfaces （54.8%） and barren land （44.9%）， driven by both natural conditions and human activities.

Key words: Horqin Sandy Land, ecological characteristics, coupling, ecosystem, functional zoning