Human activities weaken the topographic regulation of vegetation dynamics in response to climate change in the Amur River Basin

Topography significantly influences terrestrial vegetation dynamics by affecting local climate conditions like radiation and water supply. Recent studies have primarily focused on vegetation dynamics in response to climate change, yet a significant gap remains in understanding how topographic factors regulate these dynamics and how human activities influence this regulatory effect. This study analyzed the spatiotemporal changes in fractional vegetation cover (FVC) in the Amur River Basin (ARB) from 2000 to 2023 and explored the effect of topographic regulation on vegetation dynamics in response to climate change under the influence of human activities. The results indicated that FVC followed a “high in the east, low in the west” distribution pattern, with a non-significant increasing trend of 0.006/10a over the past 24 years. Changes in FVC displayed a spatial pattern of “high in the southwest, low in the northeast”. The total migration of the center of gravity for FVC exhibited a north-to-south movement in the ARB. Furthermore, global warming and increased precipitation directly promoted an improvement in FVC, while topographic factors both directly and indirectly influenced FVC changes by modulating climatic factors. Slope had a negative effect on FVC changes, while elevation had a positive effect, and the impact from aspect was minimal. Human activities weakened the topographic regulation of vegetation dynamics in response to climate change. This study provides a scientific basis for formulating ecological restoration strategies under different topographic conditions and for the management and governance of transboundary rivers.