Spatio-temporal variation of landscape pattern and the response of windbreak and sand fixation service in Hexi corridor of northern sand fixation belt.

Landscape pattern, an important factor affecting the supply and maintenance of ecosystem services, is the basis for the healthy and stable regional ecosystem and the optimal decision of land use. Taking the Hexi Corridor in the northern sand fixation belt as the study area, we quantified and analyzed the temporal and spatial variations and response relationship between landscape pattern and windbreak and sand fixation services during 2000-2020 by using the software Fragstats 4.2, the revised wind erosion equation and the spatial autocorrelation method. The results showed that, the landscape pattern of land use types changed obviously in the study area during 2000-2020, mainly from Gobi to cultivated land and from grassland to cultivated land, and that the landscape pattern tended to be diversified, heterogeneous, and fragmented. The spatial pattern of windbreak and sand fixation services was generally characterized by "high in southeast and low in northwest", with the amount of windbreak and sand fixation increasing at first and then decreasing. The windbreak and sand fixation capacity was higher in cultivated land and grassland and lower in the bare land and construction land. Shannon's diversity index, patch density and landscape shape index were all positively correlated with windbreak and sand fixation services, while mean patch size was negatively correlated with it. Our results indicated that the increases of landscape heterogeneity, the more uniform distribution, the more patches and the more complex landscape shape had a promoting effect on windbreak and sand fixation services in the Hexi corridor of the northern sand fixation belt with Gobi Desert as the dominant landscape.