Impact of Land Use/Land Cover Change on Ecosystem Service Trade-Offs/Synergies—A Case Study of Gangu County, China

The aim of this article is to analyze the impact of land use changes on trade-offs/synergies of the ecosystem service in Gangu County, Gansu province, China, from 2000 to 2020, and intends to provide a reference for decision-making on regional ecological environment protection and restoration. We analyzed the land use changes in Gangu County with the dynamic degree of single land use. Changes in ecosystem service values (ESV) were analyzed using the equivalent factor method. The temporal and spatial distribution patterns of ecosystem service trade-offs/synergies were elaborated with the help of the correlation coefficient method and local autocorrelation analysis. The impact of land use change on trade-offs/synergies of ecosystem service was analyzed according to the ecological contribution rate of land use changing and the changing of land use area. The results showed that: (1) cultivated land and grassland were the dominant land use types in Gangu County, China; the largest increase in the dynamic degree of single land use was in construction land, followed by grassland, and the largest decrease in the dynamic degree of single land use was in unused land, followed by grassland. (2) Between 2000 and 2020, the ESV showed an upward trend; the regulating service provided the largest part of the ESV among the four first ecosystem service types. The medium ESV zone occupied the largest area, and the spatial distribution pattern of ESV was high in the south and low in the north of Gangu County, China. (3) The relationships of ecosystem services were dominated by synergistic and supplemented by trade-offs. The strongest synergistic relationship was expressed between EP and BP, then, between EP and AL. Meanwhile, the strongest trade-off relationship was carried out between BP and FP. During the 20 years, the relationship of ecosystem service showed a weak shift from mainly synergistic to trade-off temporally. Spatially, the synergistic relationship was dominated and concentrated in the central and southern parts of the study area. (4) The increase in the area of grassland and forest land were the root causes resulting in the increase of ESV in Gangu County. In the time dimension, land use change had the greatest impact on the trade-off synergistic relationship between FP and all other services. In the spatial dimension, land use change has little impact on trade-offs/synergies in the northern region and more in the central and southern regions of Gangu County. The results of this study can provide a scientific basis for improving the ecological environment and promoting sustainable development in Gangu County. At the same time, it will lay the foundation for the region to realize a win–win situation between economic development and ecological protection.