Ecol Evol. 2012 Mar;2(3):538-49. doi: 10.1002/ece3.210.
It is uncertain whether the same ecological forces that structure plant and animal communities also shape microbial communities, especially those residing in soil. We sought to uncover the relative importance of present-day environmental characteristics, climatic variation, and historical contingencies in shaping soil actinobacterial communities in a long-term chronosequence. Actinobacteria communities were characterized in surface soil samples from four replicate forest stands with nearly identical edaphic and ecological properties, which range from 9500 to 14,000 years following glacial retreat in Michigan. Terminal restriction fragment length polymorphism (TRFLP) profiles and clone libraries of the actinobacterial 16S rRNA gene were constructed in each site for phenetic and phylogenetic analysis to determine whether dispersal limitation occurred following glacial retreat, or if community composition was determined by environmental heterogeneity. At every level of examination, actinobacterial community composition most closely correlated with distance, a surrogate for time, than with biogeochemical, plant community, or climatic characteristics. Despite correlation with leaf litter C:N and annual temperature, the significant and consistent relationship of biological communities with time since glacial retreat provides evidence that dispersal limitation is an ecological force structuring actinobacterial communities in soil over long periods of time.
目前尚不清楚塑造植物和动物群落的生态力量是否同样塑造了微生物群落，尤其是那些存在于土壤中的微生物群落。我们试图揭示在一个长期的时间序列中，现今的环境特征、气候变异和历史偶然性对土壤放线菌群落形成的相对重要性。我们对来自密歇根州冰川退缩后 9500 至 14000 年的四个重复森林样地的表层土壤样本中的放线菌群落进行了特征描述。在每个地点构建了放线菌 16S rRNA 基因的末端限制性片段长度多态性（TRFLP）图谱和克隆文库，进行表型和系统发育分析，以确定在冰川退缩后是否发生了扩散限制，或者群落组成是否由环境异质性决定。在每一个检查水平上，放线菌群落组成与距离（时间的替代物）的相关性最密切，而与生物地球化学、植物群落或气候特征的相关性较低。尽管与叶凋落物 C:N 和年平均温度相关，但生物群落与冰川退缩后时间的显著和一致关系为在长时间内，扩散限制是塑造土壤中放线菌群落的生态力量提供了证据。
