Effect of climate change on ecosystem service trade-offs and synergies: a case study in Huai River Basin

Uncovering changes in ecosystem services (ESs) and their interactions, and exploring the effect of climate change, is fundamental to developing ecosystem management. In this study, carbon sequestration (CS), water yield (WY), and soil conservation (SC) in the Huai River Basin (HRB) from 2001 to 2020 were investigated using meteorological and remote sensing data. The results show that CS showed a significant increasing trend (p < 0.01), especially in the central region, while WY and SC showed a non-significant increasing trend (p > 0.05), especially in the southern and eastern regions. Synergistic relationships existed between all ESs, but shifted in specific regions. The CS-SC pair shifted from trade-off to synergistic in the northeast; the CS-WY pair shifted from synergistic to trade-off in the center, east, and west; and the SC-WY pair shifted in both trade-off and synergistic relationships in the east. The main drivers of changes in these relationships included vegetation cover, topography, climate change, and land use type. Specifically, the normalized difference vegetation index (NDVI) and digital elevation model (DEM) dominated changes in the CS-SC pair, air temperature, DEM, total solar radiation, and precipitation dominated changes in the CS-WY pair, and precipitation and DEM dominated changes in the SC-WY pair. These findings will help inform the development of refined ecological restoration efforts and management policies.