Quantifying the spatiotemporal dynamics of net primary productivity under climate change using MOD17A3 NPP product and meteorological reanalysis datasets in the Yihe River Basin, East China (2001–2023)

Accurately assessing regional ecological sustainability and responses to climate change requires clarifying the spatiotemporal dynamics of Net Primary Productivity (NPP), a fundamental and climate-sensitive indicator of ecosystem structure and carbon sequestration. To clarify the spatiotemporal dynamics of NPP under climate change and provide insights for regional ecosystem management and policy formulation, this study employed trend and correlation analysis methods to quantify the spatiotemporal variations in NPP and their relationship with climate change in the Yihe River Basin (YRB), a typical warm temperate monsoon basin in East China with complex topography and diverse land use, based on MOD17A3HGF data and meteorological reanalysis datasets during 2001 and 2023. The results indicate that: (1) NPP within the basin exhibits fluctuating yet overall increasing trends, with declines predominantly observed in urban and adjacent areas; (2) The multi-year average of annual total NPP in the basin was 20.24 TgC, the multi-year average of annual mean NPP was 403.75 gC/m 2 /a, and the spatial distribution showed significant heterogeneity, with higher values in mountainous peripheral areas and lower values in urbanized central zones; (3) Both temperature and precipitation within the basin exhibit upward trends, with precipitation identified as the primary climatic factor positively correlated with NPP, suggesting it may be the key driver of NPP increase. This study confirms the dominant role of precipitation in regulating NPP dynamics in warm temperate monsoon basins, providing a scientific basis for climate adaptation and ecological management in the YRB and similar regions globally.