Microbial mediation of biogeochemical cycles revealed by simulation of global changes with soil transplant and cropping
Microbial mediation of biogeochemical cycles revealed by simulation of global changes with soil transplant and cropping
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DOI：
10.1038/ismej.2014.46
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发表时间：
2014-04
期刊：
影响因子：
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通讯作者：
Mengxin Zhao;K. Xue;Feng Wang;S. Liu;S. Bai;Bo-guang Sun;Jizhong Zhou;Yunfeng Yang
中科院分区：
文献类型：
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作者：
Mengxin Zhao;K. Xue;Feng Wang;S. Liu;S. Bai;Bo-guang Sun;Jizhong Zhou;Yunfeng Yang
尽管微生物在驱动地球化学循环中发挥着关键作用，但微生物介导的全球变化反馈机制仍然难以捉摸。最近，土壤移植已经成功地建立了一个代理，以模拟气候变化，因为目前的全球变暖的趋势一致地导致范围向高纬度转移。在中国大断面土壤南移4年后，我们发现，除了微生物生物量，土壤养分含量和参与氮循环的功能过程的同时变化，微生物功能多样性增加。然而，土壤移植的影响可以被玉米种植，这是由于一个负的相互作用。引人注目的是，氮和碳循环基因的丰度增加了这些模拟全球变化的田间试验，符合较高的土壤硝化潜力和二氧化碳（CO2）流出。进一步的研究表明，碳循环基因与裸地土壤中的CO2排放量之间存在较强的相关性，而与耕作土壤中的CO2排放量之间没有相关性，氮循环基因与硝化作用之间存在较强的相关性。这些研究结果表明，土壤移植和种植的土壤碳和氮循环的变化是可预测的，通过测量微生物的功能潜力，有助于更好地了解这些土壤功能过程的机理，并建议将微生物群落的温室气体排放模型的潜力。
Despite microbes’ key roles in driving biogeochemical cycles, the mechanism of microbe-mediated feedbacks to global changes remains elusive. Recently, soil transplant has been successfully established as a proxy to simulate climate changes, as the current trend of global warming coherently causes range shifts toward higher latitudes. Four years after southward soil transplant over large transects in China, we found that microbial functional diversity was increased, in addition to concurrent changes in microbial biomass, soil nutrient content and functional processes involved in the nitrogen cycle. However, soil transplant effects could be overridden by maize cropping, which was attributed to a negative interaction. Strikingly, abundances of nitrogen and carbon cycle genes were increased by these field experiments simulating global change, coinciding with higher soil nitrification potential and carbon dioxide (CO2) efflux. Further investigation revealed strong correlations between carbon cycle genes and CO2efflux in bare soil but not cropped soil, and between nitrogen cycle genes and nitrification. These findings suggest that changes of soil carbon and nitrogen cycles by soil transplant and cropping were predictable by measuring microbial functional potentials, contributing to a better mechanistic understanding of these soil functional processes and suggesting a potential to incorporate microbial communities in greenhouse gas emission modeling.