NPP Variability Associated with Natural and Anthropogenic Factors in the Tropic of Cancer Transect, China

The regions near the Tropic of Cancer are a latitudinal geographical zone with typical climatic, topographic, and human landscape features. It is necessary to explore region’s net primary productivity (NPP) dynamics as it combines complex topography, various vegetation types, intense activities. study sets transect (TCT) uses Carnegie–Ames–Stanford (CASA) model estimate NPP from 2000 2020. After using RESTREND method, paper calculates compares relative contributions climate variability anthropogenic activities changes. Finally, detector (Geodetector) applied evaluate how natural factors affect spatial distribution patterns results indicated that average annual 820.39 gC·m−2·yr−1 during 21 years. In addition, when varies, increases over entire area, slope 4.81 gC·m−2·yr−1, particularly in western region. Across research 63.39% 77.44% total pixels positively contribute NPP, contribution 0.90 3.91 respectively. Within western, central, eastern regions, have stronger impact on than variability, pronounced Furthermore, cover dominant factor trends across TCT three regions. contrast, shown be less influential also demonstrated effect population density GDP gradually rises. Two-factor interaction much larger any individual factor, being climatic factors. Lastly, findings revealed promote accumulation TCT, thus highlighting importance activity-led ecological restoration protection measures regional carbon sequestration balance.