土壤有机质转化及CO2释放的温度效应研究进展

土壤有机质转化对温度变化的响应,是气候变暖与全球碳循环关系中的核心问题.掌握土壤有机质对温度变化的响应规律,对准确评价气候变暖背景下,全球土壤有机质的转化至关重要.综述了国内外大量研究成果,对基质成分、基质损耗、测试方法、微生物、水分含量等因素,对土壤有机质转化与温度关系的影响机理与影响规律以及Q10的变化规律进行了探讨.提出稳定有机质与不稳定有机质温度敏感性异同问题,应作为土壤有机质转化与温度关系中的核心问题进行深入研究.同时通过分析,提出室内短期培养是首选测试方法.分析认为微生物生长温度曲线与微生物呼吸之间不存在必然联系,而在过低和过高之间,水分含量是否会影响土壤呼吸,有待进一步试验验证.提出随着城市热岛效应这一环境问题的加剧,研究及评价更大温度区间内的城市土壤有机质对温度变化的响应规律十分重要.

The temperature dependence of soil organic matter decomposition and CO2 efflux: a review

The temperature dependence of soil organic matter (SOM) is a key question in the relationship between climate warming and global carbon cycles. Understanding the response of SOM to temperature is critical in evaluating global SOM transformation under climate warming. In this review, quantities of studies are summarized and the mechanism and laws of influence of substrate components, substrate loss, test methods, microbes, water content on the temperature dependence of SOM transformation are also discussed, in addition, the variation law of Q₁₀ is discussed. The response of labile and resistant SOM to changes in temperature is proposed as the key question in further studying in relation between SOM transformation and temperature while short-term test in laboratory is recommended as the best test method. Moreover, according to the analysis in this review, there is no positive relation between microbial growth curve and temperature dependence of microbial respiration, and further study need put forward to judge whether soil respiration would be influenced by water content between too low and too high. At last, it is firstly put forward that it is significant to study and evaluate the temperature dependence of urban SOM decomposition in a big temperature range as the aggravation of the environment problem-urban heat island effect.