全球变暖背景下土壤微生物呼吸的热适应性:证据、机理和争议

土壤微生物呼吸的热适应性被认为是决定陆地生态系统对全球变暖反馈作用的潜在重要机制,可能显著改变未来的气候变化趋势,然而学术界对于这一机制是否真实存在尚有分歧。阐述了土壤微生物呼吸的热适应性概念,从证据、机理和争议3方面对已有研究进展进行了综述和分析。土壤微生物呼吸的热适应性是微生物在群落尺度上对温度变化的适应性,具有坚实的生物学与生态学理论基础,研究者们运用各类指标已在许多实验中证实土壤微生物物种及群落的呼吸过程能够在高温环境产生适应性变化。土壤微生物呼吸的热适应性机理涉及生物膜结构变化、酶活性变化、微生物碳分配比例变化和微生物群落结构变化等方面。关于土壤微生物呼吸热适应性的争议可能是由研究方法、微生物物种及环境条件的差异引起的。根据对已有研究的分析,认为土壤微生物呼吸的热适应性是真实存在的,未来的研究可进一步探索土壤微生物呼吸的热适应性机理,深入研究环境和全球变化对土壤微生物呼吸的热适应性影响,定量评估土壤微生物呼吸的热适应性对陆地生态系统反馈过程的影响。

Thermal adaptation of soil microbial respiration under global warming: evidence, mechanisms and controversies

Thermal adaptation of soil microbial respiration is considered an important mechanism for determining the feedback of terrestrial ecosystems to global warming, and can significantly modify future climate change. In this study, we clarified the concept of the thermal adaptation of soil microbial respiration, and summarized the state of research in this field from three perspectives:evidence, mechanisms and controversies. Thermal adaption of microbial respiration is a biological adaptation at the community level, and builds on solid biological and ecological theory. Using a variety of indicators, scientists have put forward substantial experimental evidence on the thermal adaptation of soil microbial respiration at the species and community level. The reported mechanisms included changes in cell membrane structure, enzyme activity, soil microbial carbon allocation, and soil microbial community structures. The discrepancies in the thermal adaptation of soil microbial respiration in literature might be caused by the differences in research methods, microbial species or environmental conditions among studies. In summary, according to various lines of evidence, we believe that soil microbial respiration could adapt to global warming. Future research should focus on 1) exploring the mechanisms of the thermal adaptation of soil microbial respiration, 2) analyzing the effects of environmental factors and global change factors on the adaptation processes, and 3) quantitatively assessing the impacts of the adaptation processes on the feedback of terrestrial ecosystems to global warming.