Variations and drivers of ecosystem services in the frozen ground regions of the Qinghai-Tibet Plateau

The alpine ecosystems of the Qinghai-Tibet Plateau (QTP) provide multiple ecosystem services. In recent decades, these ecosystem services have been profoundly affected by climate change, human activity, and frozen ground degradation. However, related research remains lacking to date in the QTP. To address this gap, the upper reaches of the Shule River, a typical cryospheric-dominated basin in the QTP, was selected. We simultaneously assessed the spatial-temporal patterns and driving factors of ecosystem services, including habitat quality (HQ), net primary productivity (NPP), water conservation (WC), carbon storage (CS), water yield (WY), green space recreation (GSR), and total ecosystem service (TES), by employing the InVEST, CASA, and Noah-MP land surface models in combination with remote sensing and field survey data. Our results showed that: (1) HQ, NPP, WC, CS, WY, and GSR all increased significantly from 2001 to 2020 at rates of 0.004 a⁻¹, 1.920 g C·m⁻²·a⁻¹, 0.709 mm·a⁻¹, 0.237 Mg⋅ha⁻¹·a⁻¹, 0.212 × 10⁸ m³·a⁻¹, and 0.038 × 10⁹ km²·a⁻¹ (P < 0.05), respectively; (2) warm and humid climates, combined with shrinking of barren, contributed to the increases in HQ, NPP, WC, CS, WY, and GSR; (3) frozen ground degradation had promoting effects on HQ, NPP, CS, GSR, and TES, while inhibiting effects were observed on WY and WC (P < 0.05); (4) synergies among ecosystem services were prominent over the past 20 years; (5) the total ecosystem service value increased significantly at a rate of 1.18 × 10⁹ CNY·a⁻¹ from 2001 to 2020 (P < 0.05), primarily due to the increase in the provisioning service value.