Laboratoire d'Ecologie Alpine, CNRS-UMR 5553, Université de Grenoble, Grenoble, France.
PLoS One. 2011 May 12;6(5):e19950. doi: 10.1371/journal.pone.0019950.
The advent of molecular techniques in microbial ecology has aroused interest in gaining an understanding about the spatial distribution of regional pools of soil microbes and the main drivers responsible of these spatial patterns. Here, we assessed the distribution of crenarcheal, bacterial and fungal communities in an alpine landscape displaying high turnover in plant species over short distances. Our aim is to determine the relative contribution of plant species composition, environmental conditions, and geographic isolation on microbial community distribution.
METHODOLOGY/PRINCIPAL FINDINGS: Eleven types of habitats that best represent the landscape heterogeneity were investigated. Crenarchaeal, bacterial and fungal communities were described by means of Single Strand Conformation Polymorphism. Relationships between microbial beta diversity patterns were examined by using Bray-Curtis dissimilarities and Principal Coordinate Analyses. Distance-based redundancy analyses and variation partitioning were used to estimate the relative contributions of different drivers on microbial beta diversity. Microbial communities tended to be habitat-specific and did not display significant spatial autocorrelation. Microbial beta diversity correlated with soil pH. Fungal beta-diversity was mainly related to soil organic matter. Though the effect of plant species composition was significant for all microbial groups, it was much stronger for Fungi. In contrast, geographic distances did not have any effect on microbial beta diversity.
CONCLUSIONS/SIGNIFICANCE: Microbial communities exhibit non-random spatial patterns of diversity in alpine landscapes. Crenarcheal, bacterial and fungal community turnover is high and associated with plant species composition through different set of soil variables, but is not caused by geographical isolation.
分子技术在微生物生态学中的出现引起了人们对理解区域土壤微生物库的空间分布以及导致这些空间模式的主要驱动因素的兴趣。在这里，我们评估了在植物物种在短距离内快速更替的高山景观中，crenarcheal、细菌和真菌群落的分布。我们的目的是确定植物物种组成、环境条件和地理隔离对微生物群落分布的相对贡献。
方法/主要发现：研究了 11 种最能代表景观异质性的生境。通过单链构象多态性来描述 crenarchaeal、细菌和真菌群落。通过使用 Bray-Curtis 不相似性和主坐标分析来检查微生物β多样性模式之间的关系。距离冗余分析和变异划分用于估计不同驱动因素对微生物β多样性的相对贡献。微生物群落倾向于生境特异性，并且没有显示出显著的空间自相关。微生物β多样性与土壤 pH 相关。真菌β多样性主要与土壤有机质有关。尽管植物物种组成对所有微生物群都有显著影响，但对真菌的影响更强。相比之下，地理距离对微生物β多样性没有影响。
结论/意义：微生物群落在高山景观中表现出非随机的多样性空间模式。crenarcheal、细菌和真菌群落的周转率很高，与植物物种组成通过不同的土壤变量相关，但不是由地理隔离引起的。
