Quantifying the independent contributions of climate and land use change to ecosystem services

Ecosystem services (ESs) are critical to human welfare and play an important role in supporting sustainable social and economic development. Climate change (CLC) and land use change (LUCC) are two of the most important factors influencing ESs. However, few studies have tried to distinguish the independent contributions of CLC and LUCC to ESs. Using meteorological, soil, land use, and remote sensing data for Liaoning Province (China) from 2000 to 2020, the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model and Carnegie-Ames Stanford Approach (CASA) model were used to construct scenario simulation frameworks based on three hy-pothetical scenarios: 1) CLC effect only; 2) LUCC effect only; 3) a combined effect of CLC and LULC. The three scenario simulation frameworks were then used to determine the independent contributions of CLC and LUCC to net primary productivity (NPP), water yield (WY), soil retention (SR), and their temporal dynamics. Results showed that under the combined effect of CLC and LULC, NPP, WY and SR in Liaoning Province exhibited a trend of gradual increase from 2000 to 2020, increasing by 124.62 gC/m2, 30.64 mm/a and 0.63 t/km2, respectively. Under the CLC only scenario, WY and SR changed by 6.24% and 2%, respectively, exhibiting a more significant effect than under the LUCC only scenario. In contrast, NPP changed by 25.71% under the LUCC only scenario, which was more significant than under the CLC only scenario. Overall, CLC was found to be the dominant factor affecting changes in WY and SR in Liaoning Province, with independent contribution rates of 81.79%-84.02% and 73.57%-85.44%, respectively, whereas LUCC was the dominant factor affecting changes in NPP with an independent contribution rate of 86.12%-92.50%. Decreased precipitation levels and an increase in temperature were the two primary factors driving fluctuations in the independent contributions of CLC to WY and SR, while large-scale forest land area damage and rapid urbanization were the two primary factors driving fluctuations in the independent contribution of LUCC to NPP. The results of this study identify the specific effects of different climatic conditions on ESs and highlight the conflict between urbanization and ecosystem service provision, providing a theoretical foundation for improving and increasing ESs and regional sustainable development in Liaoning Province.