Spatial and temporal variations in global soil respiration and their relationships with climate and land cover

Abstract

Soil respiration (<i>R</i> _s) represents the largest flux of CO₂ from terrestrial ecosystems to the atmosphere, but its spatial and temporal changes as well as the driving forces are not well understood. We derived a product of annual global <i>R</i> _s from 2000 to 2014 at 1 km by 1 km spatial resolution using remote sensing data and biome-specific statistical models. Different from the existing view that climate change dominated changes in <i>R</i> _s, we showed that land-cover change played a more important role in regulating <i>R</i> _s changes in temperate and boreal regions during 2000-2014. Significant changes in <i>R</i> _s occurred more frequently in areas with significant changes in short vegetation cover (i.e., all vegetation shorter than 5 m in height) than in areas with significant climate change. These results contribute to our understanding of global <i>R</i> _s patterns and highlight the importance of land-cover change in driving global and regional <i>R</i> _s changes.