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Global carbon emissions have exacerbated the greenhouse effect, exerting a profound impact on ecosystems worldwide. Gaining an understanding of the fluctuations in vegetation net primary productivity (NPP) is pivotal in the assessment of environmental quality, estimation of carbon source/sink potential, and facilitation of ecological restoration. Employing MODIS and meteorological data, we conducted a comprehensive analysis of NPP evolution in Chinese vegetation ecosystems (VESs), employing Theil–Sen median trend analysis and the Mann–Kendall test. Furthermore, utilizing scenario-based analysis, we quantitatively determined the respective contributions of climate change and land use change to NPP variations across various scales. The overall NPP exhibited a discernible upward trend from 2000 to 2020, with a growth rate of 5.83 gC·m−2·year−1. Forestland ecosystem (FES) displayed the highest rate of increase (9.40 gC·m−2·year−1), followed by cropland ecosystem (CES) (4.00 gC·m−2·year−1) and grassland ecosystem (GES) (3.40 gC·m−2·year−1). Geographically, NPP exhibited a spatial pattern characterized by elevated values in the southeast and diminished values in the northwest. In addition, climate change had elevated 76.39 % of CES NPP, 90.62 % of FES NPP, and 71.78 % of GES NPP. At the national level, climate change accounted for 83.14 % of the NPP changes, while land use change contributed 14.14 %. Notably, climate change emerged as the primary driving force behind NPP variations across all VEGs, with land use change exerting the most pronounced influence on CES. At the grid scale (2 km × 2 km), land use change played a substantial role in all VEGs, contributing 60.01 % in CES, 54.20 % in FES, and 55.61 % in GES of the NPP variations. © 2023 Elsevier B.V.

Revealing the driving mechanism of climatic change and anthropogenic activities on vegetation variation and identifying the ecologically sensitive zones in Southwest China are critical for formulating regional ecological restoration strategies. Herein, a NDVI-based spatial-temporal model in Southwest China from 2000 to 2021 under the influences of climatic change and anthropogenic activities alone and in combination was determined based on MODIS NDVI and in situ meteorological data using Theil-Sen median analysis, the Mann-Kendall significance test, residual analysis, and relative analysis. The results showed that on the annual scale, the NDVI, predicted NDVI, and residual NDVI significantly increased at rates of 0.0016 yr(-1), 0.0008 yr(-1), and 0.0008 yr(-1) in Southwest China from 2000 to 2021, respectively. Moreover, the NDVI, predicted NDVI, and residual NDVI significantly (P < 0.05) increased in the Guangxi Hills (GXH), Hengduan Mountains (HDM), Sichuan Basin (SCB), Yunnan-Guizhou Plateau (YGP), Zoige Plateau (ZP) and Tibetan Plateau (TP). The areas with an increase in the NDVI, predicted NDVI, and residual NDVI accounted for 81.45 %, 79.73 %, and 71.20 % of Southwest China, respectively. The NDVI variation in Southwest China was dominated by the combined effects of climatic change and anthropogenic activities, accounting for 83.22 % of the total study area. In addition, 62.76 % of the study area exhibited a greening trend. The contributions of climatic change were greater than those of anthropogenic activities for greening areas, and the opposite is true for browning areas. Innovatively, ecologically sensitive zones were identified through the Theil-Sen median analysis and Mann-Kendall significance test and accounted for 16.78 % of the total study area. Overall, this study proposed a NDVI-based spatial-temporal mode to investigate the driving mechanism of driving forces on NDVI variation, identify ecologically sensitive zones and suggest a management framewor