Romanowicz Karl J, Freedman Zachary B, Upchurch Rima A, Argiroff William A, Zak Donald R
School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109, USA
School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109, USA.
FEMS Microbiol Ecol. 2016 Oct;92(10). doi: 10.1093/femsec/fiw149. Epub 2016 Jul 6.
Predicting the impact of environmental change on soil microbial functions requires an understanding of how environmental factors shape microbial composition. Here, we investigated the influence of environmental factors on bacterial and fungal communities across an expanse of northern hardwood forest in Michigan, USA, which spans a 500-km regional climate gradient. We quantified soil microbial community composition using high-throughput DNA sequencing on coextracted rDNA (i.e. total community) and rRNA (i.e. active community). Within both bacteria and fungi, total and active communities were compositionally distinct from one another across the regional gradient (bacteria P = 0.01; fungi P < 0.01). Taxonomically, the active community was a subset of the total community. Compositional differences between total and active communities reflected changes in the relative abundance of dominant taxa. The composition of both the total and active microbial communities varied by site across the gradient (P < 0.01) and was shaped by differences in soil moisture, pH, SOM carboxyl content, as well as C and N concentration. Our study highlights the importance of distinguishing between metabolically active microorganisms and the total community, and emphasizes that the same environmental factors shape the total and active communities of bacteria and fungi in this ecosystem.
预测环境变化对土壤微生物功能的影响需要了解环境因素如何塑造微生物组成。在此，我们调查了环境因素对美国密歇根州北部阔叶林大片区域细菌和真菌群落的影响，该区域跨越500公里的区域气候梯度。我们使用高通量DNA测序对共提取的rDNA（即总群落）和rRNA（即活性群落）进行了土壤微生物群落组成的定量分析。在细菌和真菌中，总群落和活性群落在区域梯度上的组成彼此不同（细菌P = 0.01；真菌P < 0.01）。在分类学上，活性群落是总群落的一个子集。总群落和活性群落之间的组成差异反映了优势类群相对丰度的变化。总微生物群落和活性微生物群落的组成在整个梯度上因地点而异（P < 0.01），并且受到土壤湿度、pH值、土壤有机碳羧基含量以及碳和氮浓度差异的影响。我们的研究强调了区分代谢活跃微生物和总群落的重要性，并强调相同的环境因素塑造了该生态系统中细菌和真菌的总群落和活性群落。
