Center for Ecological and Environmental Sciences, Key Laboratory for Space Bioscience and Biotechnology, Northwestern Polytechnical University, Xi'an, China.
State Key Laboratory of Loess and Quaternary Geology (SKLLQG), and Key Laboratory of Aerosol Chemistry and Physics, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
Glob Chang Biol. 2018 Oct;24(10):4816-4826. doi: 10.1111/gcb.14394. Epub 2018 Aug 1.
Extracellular enzymes catalyze rate-limiting steps in soil organic matter decomposition, and their activities (EEAs) play a key role in determining soil respiration (SR). Both EEAs and SR are highly sensitive to temperature, but their responses to climate warming remain poorly understood. Here, we present a meta-analysis on the response of soil cellulase and ligninase activities and SR to warming, synthesizing data from 56 studies. We found that warming significantly enhanced ligninase activity by 21.4% but had no effect on cellulase activity. Increases in ligninase activity were positively correlated with changes in SR, while no such relationship was found for cellulase. The warming response of ligninase activity was more closely related to the responses of SR than a wide range of environmental and experimental methodological factors. Furthermore, warming effects on ligninase activity increased with experiment duration. These results suggest that soil microorganisms sustain long-term increases in SR with warming by gradually increasing the degradation of the recalcitrant carbon pool.
细胞外酶催化土壤有机质分解的限速步骤，其活性（EEAs）在决定土壤呼吸（SR）方面起着关键作用。EEAs 和 SR 对温度都非常敏感，但它们对气候变暖的响应仍知之甚少。在这里，我们对土壤纤维素酶和木质素酶活性和 SR 对变暖的响应进行了荟萃分析，综合了 56 项研究的数据。我们发现，变暖显著增强了木质素酶活性 21.4%，但对纤维素酶活性没有影响。木质素酶活性的增加与 SR 的变化呈正相关，而纤维素酶则没有这种关系。木质素酶活性的变暖响应与 SR 的响应比广泛的环境和实验方法学因素更为密切相关。此外，变暖对木质素酶活性的影响随着实验持续时间的增加而增加。这些结果表明，土壤微生物通过逐渐增加对难降解碳库的降解，维持着 SR 的长期变暖。
