## 3 Results
### Quantitative Discrimination of Climate-Human Effect on Vegetation NPP
Figure 8b and Appendix A Figure A7 showed that during 2000-2010, zones with an increase in vegetation NPP promoted by human activities were mainly distributed in southern China, and zones with contribution rates greater than 80% accounted for the highest proportion (77.29%), which were mainly in Guizhou Province, Sichuan Province, Henan Province, Yunnan Nasheng, Hubei Province, and eastern Inner Mongolia. Zones with contribution rates of 0%-20% and 60%-80% accounted for only 5.60%. Figure 8: The spatial distribution of the contribution rate of climate–human interactions to the increase in vegetation NPP across different historical periods. (**a**) Climate change (2000–2010); (**b**) human activities (2000–2010); (**c**) climate change (2011–2022); (**d**) human activities (2011–2022). From 2011 to 2022, climate change contributed 36.03% of the increase in vegetation NPP (Figure 8c,d). In terms of climate (Figure 8c), zones with contribution rates of 80-100% accounted for the largest proportion, comprising 79.78%, which were mainly distributed in Heilongjiang, Yunnan, Guangdong, Jiangsu, and Ningxia. Zones with contribution rates of 0%-20% had the smallest area proportion, comprising 4.22%. In terms of human activities (Figure 8d), zones with increases in vegetation NPP promoted by human activities were distributed in inland China, such as the patch areas formed by Shandong Province, Fujian Province, and Zhejiang Province; the Qinghai-Tibet Plateau; and the junction of Qinghai Province and Ningxia Hui Autonomous Region. From the perspective of contribution levels, zones with contribution rates of 80%-100% accounted for the largest proportion, at 74.65%, which were mainly located in each patch area, followed by zones with contribution rates of 40%-60%, accounting for 7.12%, which were mainly distributed at the junction of Shanxi Province and Inner Mongolia Autonomous Region. Areas with a reduction in vegetation NPP caused by climate-human interaction are less extensive than areas with an increase in vegetation NPP, accounting for only 20.1% (Figure 9 and Appendix A Figure 10). In terms of climate change (Figure 9a), zones with contribution rates of 80%-100% had the largest area proportion, comprising 88.17%, which was mostly located in the southern part. The reduction in vegetation NPP caused by human activities was mostly located in the middle of the study area, such as the junction of Anhui Province and Zhejiang Province, southern Qinghai Province, and central and western Tibet (Figure 9b). Zones with contribution rates of 80%-100% accounted for the highest proportion, at 74.54%, which was mainly distributed in Guangdong and Guangxi. Zones with vegetation NPP decreases induced by climate change had larger areas than those caused by human activities. Our comprehensive analysis showed that the decrease in vegetation NPP during 2000-2010 was mainly related to climate change. Figure 9: Spatial distribution of contribution rate of vegetation NPP decrease induced by climate–human interactions. (**a**) Climate change (2000–2010); (**b**) human activities (2000–2010); (**c**) climate change from (2011–2022); (**d**) human activities (2011–2022). Areas with reduced vegetation NPP accounted for 25.1%, which was smaller than areas with increased vegetation NPP (Figure 9c,d). In terms of climate change (Figure 9c), zones with contribution rates of 80%-100% accounted for the largest proportion, at 86.81%, being mostly located in the southern part of the study area, such as the Tibet Autonomous Region, Jiangxi Province, and Hubei Province. Zones with contribution rates of 60%-80% were mostly located in the northern parts, accounting for only 2.80%. In terms of human activities (Figure 9d and Appendix A Figure A8), zones with contribution rates of 80%-100% accounted for the largest proportion, at 92.05%, which were mainly distributed across all provinces and cities. Zones with contribution rates of 0%-20% accounted for the smallest proportion, comprising only 1.78%.