A global meta-analysis on freeze-thaw effects on soil carbon and phosphorus cycling
A global meta-analysis on freeze-thaw effects on soil carbon and phosphorus cycling
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DOI：
10.1016/j.soilbio.2021.108283
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发表时间：
2021-05-10
影响因子：
9.7
通讯作者：
Hagedorn, Frank
中科院分区：
文献类型：
--
作者：
Gao, Decai;Bai, Edith;Hagedorn, Frank
全球气候变化引起的冻融循环频率和强度的增加可能影响陆地生态系统土壤碳、磷循环。然而，对FTC对土壤C和P循环的响应仍然缺乏全面的了解。在这里，我们收集了2471个观测数据，从75个出版物，并进行了荟萃分析的土壤C和P循环和化学计量的C，N和P循环FTC的响应。结果表明，FTC处理显著增加了土壤溶解性有机碳（+38%）、瞬时和累积CH 4（分别为+41%和+59%）、溶解性有机C淋溶（+62%）、全盐可提取P（+27%）、溶解性有机P（+27%）（+9.4%）、溶解态全磷（+312%）、溶解态有机磷（+30%）、溶解态无机磷（+115%）的淋溶量和速效氮磷比（+21%）。FTC处理显著降低了土壤微生物量C（-10%）、纤维素酶活性（-16%）、微生物量P（-10%）和微生物量C/N（-8.1%）。FTC后土壤可溶性C和P增加的可能原因是死亡的土壤微生物释放C和P以及土壤结构的变化增强了有机质的有效性。FTC的平均效应量随FTC强度的增加而增加，这可能也是实验室观测到的土壤C、P库和通量对FTC的响应高于田间试验的主要原因。然而，FTC的平均效应量一般随着FTC的持续时间和频率的增加而降低，很可能是由于微生物吸收和浸出导致的基质消耗。该荟萃分析的结果有助于更好地理解土壤C和P库和通量对FTC的整体响应，为更准确地预测未来全球气候变化对土壤地球化学循环的影响提供了基础。
Enhanced frequency and intensity of freeze-thaw cycle (FTC) owing to global climate change may influence soil carbon (C) and phosphorus (P) cycling in terrestrial ecosystems. However, a comprehensive understanding of soil C and P cycling in response to FTC is still lacking. Here, we compiled data of 2471 observations from 75 publications and conducted a meta-analysis on the responses of soil C and P cycling and the stoichiometry of C, N and P cycling to FTC. Results showed that experimental FTC significantly increased soil dissolved organic C (+38%), instant and cumulative CH4 (+41% and +59%, respectively), dissolved organic C leaching (+62%), total salt-extractable P (+27%), dissolved organic P (+9.4%), leaching of dissolved total P (+312%), dissolved organic P (+30%), and dissolved inorganic P (+115%), and the ratio of available N to P (+21%). In contrast, soil microbial biomass C (-10%), cellulase activity (-16%), microbial biomass P (-10%), and the ratio of microbial biomass C to nitrogen (-8.1%) significantly decreased under FTC treatments. The likely reason for the increases in soluble soil C and P after FTC is the C and P release from dead soil microorganisms and changes in soil structure enhancing organic matter availability. The mean effect size of FTC generally increased with increasing FTC intensity, which was probably also the main reason for higher responses of soil C and P pools and fluxes to FTC observed in laboratory than in field experiments. However, mean effect sizes of FTC generally decreased with increasing duration and frequency of FTC, very likely due to substrate depletion through microbial uptake and leaching. The results of this meta-analysis contribute to a better understanding of the overall responses of soil C and P pools and fluxes to FTC, providing the basis for more accurate prediction of the impacts of future global climate change on biogeochemical cycles.