Soil carbon loss with warming: New evidence from carbon-degrading enzymes.
GLOBAL CHANGE BIOLOGY 2020;
26:1944-1952. [PMID:
31909849 DOI:
10.1111/gcb.14986]
[Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
Climate 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.
Collapse