Soil carbon loss with warming: New evidence from carbon‐degrading enzymes

• DOI: 10.1111/gcb.14986
• Publication Date: 2020-01-07T18:00:22Z
• Authors: Ji Chen; Lars Elsgaard; Kees Jan van Groe...; Jørgen E. Olesen; Zhi Liang; Yu Jiang; Poul E. Lærke; Yuefang Zhang; Yiqi Luo; Bruce A. Hungate; Robert L. Sinsabaugh; Uffe Jørgensen
• Keywords: 2. Zero hunger; 0301 basic medicine; extracellular enzyme; climate-carbon feedback; soil microorganism; 15. Life on land; labile carbon pool; 03 medical and health sciences; 13. Climate action; soil carbon storage; warming duration; recalcitrant carbon pool; experimental warming

AbstractClimate warming affects soil carbon (C) dynamics, with possible serious consequences for soil C stocks and atmospheric CO2 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.