Vegetation cover moderates the effect of warming on soil respiration from alpine ecosystems globally

Soil respiration represents a key C flux to the atmosphere. Alpine ecosystems are changing due to warming and plant migrations, yet the response of soil respiration remains uncertain. We use a globally distributed network of field experiments that deploy warming chambers and remove dominant plant species at high and low elevation alpine sites to assess how these treatments and their interactions alter soil respiration across varied environmental conditions. Warming increased soil respiration by 15.0% while dominant species removal reduced it by 12.1%. Warming had greater effects on soil respiration when plant cover was reduced, suggesting different temperature sensitivities of the autotrophic and heterotrophic components of soil respiration. Across all sites, higher plant cover and temperatures stimulated soil respiration, while soil moisture and plant cover x temperature interactions constrained it. Despite significant site-level variation, warming and increasing plant biomass will stimulate soil respiration in the alpine biome, augmenting atmospheric carbon concentrations.