Opposite changes in ecosystem service value between permafrost and non-permafrost regions of the Qinghai-Tibet Plateau over the 21st century

Accurately assessing ecosystem service value (ESV) is crucial for implementing ecological compensation and formulating sustainable management policy. However, long-term spatial-temporal patterns of ESV remain limited, particularly in permafrost regions. Here, based on different spatial regions across the entire Qinghai-Tibet Plateau (QTP), encompassing both permafrost and non-permafrost regions, we assess ESV variations throughout the 21st century by combining multi-source data with six models. We find that ESV increased notably at a rate of 7.86 × 10 9 CNY per decade from 2001 to 2020, but is projected to decline significantly from 2021 to 2100 in the QTP. Notably, ESV declines significantly in permafrost regions over the 21st century, primarily due to the severe degradation of transitional and unstable permafrost regions. In contrast, ESV increases markedly in non-permafrost regions, mainly caused by the transition of permafrost into non-permafrost. Regulating service value contributes the most to ESV across different spatial scales. Moreover, fractional vegetation cover is the dominant factor influencing ESV. Our findings provide scientific support for the formulation of ecological management strategies in alpine regions.