Spatiotemporal patterns and alleviating of grassland overgrazing under current and future conditions in Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau (QTP) is a crucial region for biodiversity conservation and global ecosystem services supply, and its grassland carrying capacity (GCC) is directly related to both herders' livelihoods and the implementation of ecosystem conservation and restoration programs. However, the spatiotemporal distribution of GCC within the QTP and grasslands’ responses to future climate change remain unclear. Here, we evaluated the spatiotemporal characteristics of GCC for 60 years and its load during 2000–2020, and then classified levels of early-warning based on whether the grassland is currently overgrazed, and whether the overgrazing is increasing over time. Results showed that (1) GCC increased from 86.15 million to 97.70 million sheep units (SU) during 2000–2020, and GCC was higher in the east than that in the west QTP. (2) Overgrazing was alleviated due to livestock reduction after 2010 and GCC has grown more, but remains serious. The counties with stronger GCC showed more serious overgrazing. (3) Annual mean GCC was projected to increase by 0.05 SU·km⁻² and 1.22 SU·km⁻² under Shared Socioeconomic Pathways (SSPs) 126 and SSP460, respectively. Overgrazing is likely to be greatly alleviated in the future with climate change and livestock reductions in the QTP. Our study gives practical advice for adjusting the development pattern of grassland animal husbandry and provides recommendations for key implementation areas of ecosystem conservation and restoration programs of grassland ecosystems.