Spatiotemporal Patterns of NPP and Hydrothermal Sensitivity Under Land-Use Change: A Case Study of Guangxi, China

Amidst the intensifying challenges of global climate change and the increasing demand for regional sustainable development, accurately assessing the contributions and dynamic characteristics of different land-use types to regional carbon sink patterns is essential for understanding ecosystem carbon cycling mechanisms and optimizing carbon management strategies. Based on land-use and Net Primary Productivity (NPP) remote sensing data from 2018 to 2022, this study employs a land-use change coding method and a hydrothermal (temperature and precipitation) sensitivity coefficient approach to analyze the spatiotemporal variation in NPP in Guangxi Zhuang Autonomous Region and its differential responses to hydrothermal conditions. On this basis, sensitivity coefficients were calculated to assess the spatial patterns of NPP sensitivity to temperature and precipitation, revealing spatial sensitivity characteristics and potential ecological risks. The results indicate significant differences in NPP variations among different land-use types, with broadleaf forests, mixed forests, savannas, and croplands identified as the primary contributors to NPP flows. Additionally, the response of NPP to hydrothermal factors exhibits clear spatial heterogeneity: precipitation sensitivity hotspots are mainly concentrated in the northern and southern ecosystems, while temperature sensitivity hotspots are predominantly located in the northern region. Further analysis reveals that the ecosystems in the central and northern regions are more sensitive to temperature changes, whereas coastal areas exhibit higher stability.