School of Natural Resources & Environment, University of Michigan, Ann Arbor, MI 48109, USA.
Mol Ecol. 2010 Apr;19(7):1469-82. doi: 10.1111/j.1365-294X.2010.04566.x.
The Agaricomycotina are a phylogenetically diverse group of fungi that includes both saprotrophic and mycorrhizal species, and that form species--rich communities in forest ecosystems. Most species are infrequently observed, and this hampers assessment of the role that environmental heterogeneity plays in determining local community composition and in driving beta-diversity. We used a combination of phenetic (TRFLP) and phylogenetic approaches [Unifrac and Net Relatedness Index (NRI)] to examine the compositional and phylogenetic similarity of Agaricomycotina communities in forest floor and surface soil of three widely distributed temperate upland forest ecosystems (one, xeric oak--dominated and two, mesic sugar maple dominated). Generally, forest floor and soil communities had similar phylogenetic diversity, but there was little overlap of species or evolutionary lineages between these two horizons. Forest floor communities were dominated by saprotrophic species, and were compositionally and phylogenetically similar in all three ecosystems. Mycorrhizal species represented 30% to 90% of soil community diversity, and these communities differed compositionally and phylogenetically between ecosystems. Estimates of NRI revealed significant phylogenetic clustering in both the forest floor and soil communities of only the xeric oak-dominated forest ecosystem, and may indicate that this ecosystem acts as a habitat filter. Our results suggest that environmental heterogeneity strongly influences the phylogenetic beta-diversity of soil inhabiting Agaricomycotina communities, but has only a small influence on forest floor beta-diversity. Moreover, our results suggest that the strength of community assembly processes, such as habitat filtering, may differ between temperate forest ecosystems.
担子菌门是真菌中一个具有丰富多样性的类群，包括腐生和菌根物种，并且在森林生态系统中形成了物种丰富的群落。大多数物种很少被观察到，这阻碍了对环境异质性在决定局部群落组成和驱动β多样性方面所起作用的评估。我们使用表型（TRFLP）和系统发育方法（Unifrac 和网络亲缘关系指数（NRI））组合，研究了三种广泛分布的温带旱地森林生态系统（一种，干旱栎木主导，两种，湿润糖枫主导）的森林地表和表层土壤中担子菌门群落的组成和系统发育相似性。一般来说，森林地表和土壤群落具有相似的系统发育多样性，但这两个层面的物种或进化谱系很少重叠。森林地表群落主要由腐生物种组成，在所有三个生态系统中都具有相似的组成和系统发育。菌根物种占土壤群落多样性的 30%至 90%，这些群落在生态系统之间在组成和系统发育上存在差异。NRI 的估计表明，只有干旱栎木主导的森林生态系统的森林地表和土壤群落中存在显著的系统发育聚类，这可能表明该生态系统起到了栖息地筛选的作用。我们的研究结果表明，环境异质性强烈影响着土壤中担子菌门群落的系统发育β多样性，但对森林地表的β多样性影响较小。此外，我们的研究结果表明，群落组装过程（如栖息地筛选）的强度可能因温带森林生态系统而异。
