A global meta-analysis of forest harvesting effects on soil respiration, its components, and temperature sensitivity

Understanding the effects of timber harvesting on soil respiration, including its autotrophic and heterotrophic components and their temperature sensitivity, is crucial for predicting how forest management affects the carbon cycle. Here, we conducted a meta-analysis to assess these effects on a global scale, synthesizing data from 1656 paired observations from 143 studies worldwide. On average, harvesting increased soil respiration by 6.0 %, most significantly in coniferous forests and subtropical regions. The response of total soil respiration was more closely coupled to changes in its heterotrophic than in its autotrophic component. The positive effects of harvesting on both respiration components decreased with increasing harvest intensity and were positively correlated with changes in soil nitrogen, root biomass, and microbial biomass carbon. Harvesting reduced the temperature sensitivity of soil respiration by 6.4 %, particularly in coniferous forests and temperate regions. The temperature sensitivity of soil autotrophic respiration increased in the first years after harvesting compared to the control but was significantly lower in later stages (c. > 6 years) after harvesting. Furthermore, the effects of harvesting on soil respiration, its components and temperature sensitivity varied greatly between post-harvest treatments and seasons of measurement. The results of our synthesis provide a basis for refining ecosystem models to better predict soil carbon dynamics in harvested forests on a global scale.