Changes in major ecosystem services and their trade-offs and synergy in typical counties of the northern desert belt

Clarifying the changes in ecosystem services and trade-offs in typical counties in the northern sand control belt is of great significance for promoting the optimal allocation of natural resources and precise governance of land and space. Based on the InVEST model, and correlation coefficient and spatial autocorrelation methods, and taking Minqin County as a case, this study analyzed the temporal and spatial changes in and trade-off synergies of the main ecosystem services of windbreak and sand fixation, carbon storage, and food supply in a typical county in the northern sand control belt. The results show that 1) the service quality of the main ecosystems in Minqin County has improved significantly in the past 20 years, and the total amount of windbreak and sand fixation, carbon storage, and food supply increased by 8.64 × 10⁷ kg, 2.17 × 10⁷ t, and 1.02 × 10⁶ t, respectively. 2) During the study period, there was a strong synergistic relationship between windbreak and sand fixation and carbon storage, whereas the synergistic relationship between carbon storage and food supply weakened gradually, and the trade-off relationship between windbreak and sand fixation and food supply increased gradually. 3) In terms of spatial patterns, the heterogeneity of the trade-off and synergistic relationship between different types of services was significant (P < 0.05), and the regional differences were highly evident. 4) The spatial autocorrelation coefficients of ecosystem services did not change significantly during the study period; however, the agglomeration characteristics of different regions showed large spatial differences.