Soil carbon loss with warming: New evidence from carbon‐degrading enzymes
Ji Chen, Lars Elsgaard, Kees Jan van Groenigen, Jørgen E. Olesen, Zhi Liang, Yu Jiang, Poul Erik Lærke, Yuefang Zhang, Yiqi Luo, Bruce A. Hungate, Robert L. Sinsabaugh, Uffe Jørgensen
Abstract
concentrations. However, the mechanisms underlying changes in soil C storage are not well understood, hampering long-term predictions of climate C-feedbacks. The activity of the extracellular enzymes ligninase and cellulase can be used to track changes in the predominant C sources of soil microbes and can thus provide mechanistic insights into soil C loss pathways. Here we show, using meta-analysis, that reductions in soil C stocks with warming are associated with increased ratios of ligninase to cellulase activity. Furthermore, whereas long-term (≥5 years) warming reduced the soil recalcitrant C pool by 14%, short-term warming had no significant effect. Together, these results suggest that warming stimulates microbial utilization of recalcitrant C pools, possibly exacerbating long-term climate-C feedbacks.