Disentangling climate-driven and anthropogenic activities-induced impacts on net ecosystem productivity in the Yunnan-Kweichow Plateau over the past two decades

Abstract

The Yunnan-Kweichow Plateau (YKP), a representative ecologically fragile zone, is subject to dual pressures from intensified climate change and anthropogenic activities. The specific mechanisms of how Net Ecosystem Productivity (NEP) responds to these changes remain unclear, whose relative contributions remain poorly quantified. This study conducts spatiotemporal quantification analysis of NEP dynamics and influencing factors in the YKP from 2001 to 2020, which integrated a linear regression, shifting center of gravity, Mann-Kendall trend test, partial correlation analysis, and random forest. The results showed an enhancement in NEP within the YKP (slope = 2.42 g C·m⁻²·yr⁻¹, p < 0.05). Overall, climate change and anthropogenic activities contributed 1.86 g C·m⁻²·yr⁻¹ and 0.76 g C·m⁻²·yr⁻¹ to NEP variations, respectively. In terms of climate impact, temperature and precipitation are the main drivers affecting vegetation change, while radiation has the least influence. The importance of precipitation on NEP has been increasing by an upward trend, particularly in non-humid regions (slope = 0.31, p < 0.05) and grassland (slope = 0.45, p < 0.05). Besides, although the impact of climate change is dominant throughout the region, in areas affected by anthropogenic activities and climate change, the influence of anthropogenic activities is dominant and has a positive impact on the vegetation growth of YKP and NEP, especially in forest areas. The research elucidates the coupling mechanisms of how anthropogenic activities and climate change drive vegetation dynamics in the YKP region, providing key insights for boosting carbon sink capacity and promoting ecological sustainability.