Evolution Patterns of Carbon Flux in the Alpine Meadow Ecosystem

Abstract Meadow ecosystems, which play a key role in terrestrial systems, help regulate the global carbon cycle. This study employs a synergistic analysis of ground‐based and multi‐source remote sensing data to reveal the spatiotemporal patterns and drivers of carbon balance in the eastern Pamir alpine meadows. The main findings are as follows: (a) Carbon flux dynamics exhibit significant temporal heterogeneity: the ecosystem maintains a continuous daily carbon sink, with net CO 2 absorption during the growing season (accounting for 91% of its sink function); the net ecosystem exchange (NEE) peaks in August at −0.19 mg m −2 s −1 . (b) Carbon exchange is co‐regulated by multiple factors, with dominant drivers varying over space and time. Photosynthetically active radiation (PAR) and vapor pressure deficit (VPD) are the most important variables explaining the variance in CO 2 flux. (c) Spatial patterns of gross primary productivity (GPP), derived using an improved light use efficiency model under climate change, show that total primary productivity is positively correlated with NDVI. Higher GPP (>3.2 g C m −2 d −1 ) occurs in the southeastern and central parts of the plateau (characterized by favorable water and heat conditions), while lower values are found in the arid northwest. Over the past 20 years, GPP has increased significantly at a rate of 4.09% per year ( p < 0.05), particularly in meadows with high vegetation coverage (>65%), indicating that vegetation recovery enhances carbon sink capacity under climate change.