Analysis of driving factors for spatiotemporal changes in carbon sources/sinks in Yangtze River Economic Belt

Abstract The carbon cycle of terrestrial ecosystems acts a fundamental role in regulating the global carbon balance, making it an essential component in the study of both global and regional climate dynamics and the impacts of human activities. As an extremely important characteristic of ecosystems, net ecosystem productivity (NEP) characterizes the carbon accumulation rate of ecosystems. Clarifying its spatiotemporal dynamics and underlying driving mechanisms is critical for supporting effective ecosystem protection and restoration. This study estimates the NEP based on remote sensing data and analyzes its spatiotemporal variation characteristics from 2001 to 2023 in the Yangtze River Economic Belt (YEB) by using trend analysis methods. Subsequently, explore the driving mechanisms between the influencing factors and NEP by utilizing the Geodetector. The following results were obtained: (1) In terms of time, the NEP in the YEB exhibited a fluctuating upward trend from 2001 to 2023, from 174gC·(m 2 ·a) –1 to 209gC·(m 2 ·a) –1 . (2) In terms of space, NEP shows a distribution feature of "higher values in the southwest and lower values in the northeast" in the YEB. (3) The factor detection results indicate that temperature, fraction vegetation coverage and elevation are the main influencing factors of NEP spatial differentiation in the YEB. The explanatory power of each factor is more significant after interaction with others than when it acts as an individual factor, among interaction between elevation and vegetation coverage is the greatest.