Temperature rather than N availability determines root exudation of alpine coniferous forests on the eastern Tibetan Plateau along elevation gradients.

This article investigates the ecological drivers of root exudation rates in two alpine coniferous forests—Abies faxoniana and Abies georgei—along elevation gradients on the eastern Tibetan Plateau. The study found that root exudation rates significantly decrease with increasing elevation and are primarily controlled by elevation-dependent air temperature rather than soil moisture or nitrogen availability. Structural equation modeling indicated that temperature influences root exudation both directly and indirectly through effects on fine root morphological traits and biomass. These findings suggest that temperature-driven physiological adaptations in trees play a dominant role in regulating belowground carbon fluxes, with important implications for soil carbon dynamics and nutrient cycling under climate warming in alpine forest ecosystems.