Seasonal and ecohydrological regulation of active microbial populations involved in DOC, CO2, and CH4 fluxes in temperate rainforest soil
Seasonal and ecohydrological regulation of active microbial populations involved in DOC, CO2, and CH4 fluxes in temperate rainforest soil
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DOI：
10.1038/s41396-018-0334-3
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发表时间：
2018-12
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影响因子：
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通讯作者：
David J. Levy-Booth;I. Giesbrecht;C. Kellogg;T. Heger;D. D’Amore;P. Keeling;S. Hallam;W. Mohn
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文献类型：
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作者：
David J. Levy-Booth;I. Giesbrecht;C. Kellogg;T. Heger;D. D’Amore;P. Keeling;S. Hallam;W. Mohn
太平洋沿岸温带雨林（PCTR）是全球碳循环和出口的热点地区。然而，微生物对 PCTR 土壤碳循环过程的影响尚不清楚。我们通过整合地球化学、微气象学以及来自 216 个土壤 DNA 和 RNA 文库的真核和原核核糖体扩增子 (rRNA) 测序，开发并测试了 PCTR 土壤中季节性微生物碳循环的概念模型。湿季期间土壤湿度和 pH 值增加，与泥炭沼泽中的净 CO2 通量和沼泽森林土壤中的净 CH4 通量显着相关。这些位点的真菌演替的特点是占 ITS 文库 41% 的古根瘤菌系统发育型的明显更替。 rRNA 文库中的厌氧原核生物（包括互养细菌科和甲烷微生物）在雨季有所增加。在 rRNA 和宏转录组网络分析后，这些系统发育型的假定活跃群体及其硫酸盐和 CH4 循环的生物地球化学标记基因分别呈正相关。后者的系统发育型与CH4通量呈正相关(r= 0.46,p< 0.0001)。宏转录组分析支持系统发育型功能分配。我们认为活跃的微生物种群主要对水文、pH 值和养分有效性的变化做出反应。冬季观察到的微生物碳输出增加可能会对 PCTR 中的气候-土壤反馈产生影响。
The Pacific coastal temperate rainforest (PCTR) is a global hot-spot for carbon cycling and export. Yet the influence of microorganisms on carbon cycling processes in PCTR soil is poorly characterized. We developed and tested a conceptual model of seasonal microbial carbon cycling in PCTR soil through integration of geochemistry, micro-meteorology, and eukaryotic and prokaryotic ribosomal amplicon (rRNA) sequencing from 216 soil DNA and RNA libraries. Soil moisture and pH increased during the wet season, with significant correlation to net CO2flux in peat bog and net CH4flux in bog forest soil. Fungal succession in these sites was characterized by the apparent turnover ofArchaeorhizomycetesphylotypes accounting for 41% of ITS libraries. Anaerobic prokaryotes, includingSyntrophobacteraceaeandMethanomicrobiaincreased in rRNA libraries during the wet season. Putatively active populations of these phylotypes and their biogeochemical marker genes for sulfate and CH4cycling, respectively, were positively correlated following rRNA and metatranscriptomic network analysis. The latter phylotype was positively correlated to CH4fluxes (r= 0.46,p< 0.0001). Phylotype functional assignments were supported by metatranscriptomic analysis. We propose that active microbial populations respond primarily to changes in hydrology, pH, and nutrient availability. The increased microbial carbon export observed over winter may have ramifications for climate–soil feedbacks in the PCTR.