The Qinghai Lake Basin, a typical ecologically vulnerable, high-altitude, cold region, requires coordinated ecosystem conservation and socio-economic development to achieve territorial sustainability. Based on the Production–Living–Ecological Space (PLES) framework, this study used land use data from five periods between 2000 and 2020 and integrated the PLUS and InVEST models to examine and simulate the evolution of PLES patterns and carbon stock under four scenarios—natural development, ecological protection, economic development, and sustainable development—in 2035. The results show that the PLES pattern in the Qinghai Lake Basin remained generally stable from 2000 to 2020, with ecological space dominating the landscape, while production and living spaces expanded slowly. Carbon stock increased from 214.73 × 10⁶ Mg to 264.70 × 10⁶ Mg, representing a growth rate of 23.27%. Its spatial distribution is highly consistent with the PLES pattern, with ecological space being the main contributor. By 2035, carbon stock is projected to slightly increase under the natural development scenario; under the ecological protection scenario, the expansion of ecological space leads to an increase in carbon stock; it decreases under the economic development scenario due to the encroachment of ecological space by construction land expansion; and under the sustainable development scenario, which balances economic development and ecological protection, carbon stock increases by 4.87 × 10⁶ Mg, achieving the best overall performance. Therefore, it is essential to properly coordinate the relationships among PLES components to achieve synergistic enhancement of ecosystem services and regional sustainable development. The findings provide methodological references and decision support for sustainable development in the Qinghai–Tibet Plateau and other ecologically vulnerable regions.

As a vital ecological security barrier and climate regulator in northwestern China, the Qinghai Lake Basin (QLB) holds significant strategic value for regional ecological conservation and national park development. This study, utilizing land use data from 2010 to 2023 and integrating the InVEST and GeoDetector models, systematically investigated the spatiotemporal dynamics of soil conservation (SC) and its underlying driving mechanisms. The results indicate the following: (1) During the study period, SC services exhibited a gradual declining trend across the selected years, with total SC decreasing from 14.64 × 10³ t to 7.49 × 10³ t. Spatially, high-value areas were predominantly concentrated in the high-altitude forest–grassland ecotones along the basin margins, whereas low-value areas were mainly distributed in the low-altitude zones surrounding the lake and in the northwestern corner of the basin. (2) Among different land use types, forestland, bare land, and grassland constituted the dominant contributing categories, with bare land exhibiting the highest sediment export (SE) intensity (ranging from 8.93 to 19.13 t·hm⁻²·a⁻¹), thereby serving as the primary erosion source area. Along the elevational gradient, the mid-to-high elevation zones (3500–4500 m) contributed the most to total SC, with SC intensity increasing progressively with rising elevation. With respect to slope classes, total SC was predominantly concentrated in the gentle-to-moderate slope zones (5–25°), whereas SC intensity exhibited a non-linear increase with increasing slope steepness. (3) Slope was identified as the single factor with the strongest explanatory power regarding the spatial heterogeneity of SC, and the coupled interactions of “topography–soil–vegetation” exerted a synergistic regulatory effect on SC function. It is recommended that priority attention be given to the mid-to-high elevation contribution zones (3500–4500 m), the total SC contribution zones on gentle-to-moderate slopes (5–25°), and the extremely steep slope areas (>35°) with high erosion risk, so as to implement differentiated soil and water conservation measures. These findings provide a scientific basis for ecological protection, soil and water conservation strategy formulation, and sustainable development in the QLB.