Division of Biology and Ecological Genomics Institute, Kansas State University, Manhattan, Kansas 66506, USA.
Mycologia. 2010 Sep-Oct;102(5):1027-41. doi: 10.3852/09-316.
We used 454 sequencing of the internal transcribed spacer region to characterize fungal communities in tallgrass prairie soils subdivided into strata 0-10, 10-20, 30-40 and 50-60 cm deep. The dataset included more than 14000 fungal sequences distributed across Basidiomycota, Ascomycota, basal fungal lineages and Glomeromycota in order of decreasing frequency. As expected the community richness and diversity estimators tended to decrease with increasing depth. Although species richness was significantly reduced for samples from the deeper profiles, even the deepest stratum sampled contained richness of more than a third of that in the topmost stratum. More importantly, nonparametric multidimensional scaling (NMS) ordination analyses indicated that the fungal communities differed across vertical profiles, although only the topmost and deepest strata were significantly different when the NMS axis scores were compared by ANOVA. These results emphasize the importance of considering the fungal communities across the vertical strata because the deeper soil horizons might maintain a distinct community composition and thus contribute greatly to overall richness. The majority of operational taxonomic units (OTUs) declined in frequency with increasing depth, although a linear regression analysis indicated that some increased with increasing depth. The OTUs and BLAST-assigned taxa that showed increasing frequencies were mainly unculturable fungi, but some showed likely affinities to families Nectriaceae and Venturiaceae or to genus Pachnocybe. Although the ecological roles of the fungi in the deeper strata remain uncertain, we hypothesize that the fungi with preferences for deeper soil have adequate access to substrates and possess environmental tolerances that enable their persistence in those environments.
我们使用 454 测序技术对分为 0-10、10-20、30-40 和 50-60 厘米深的层状的高草草原土壤中的真菌群落进行了特征描述。该数据集包括超过 14000 个真菌序列，按出现频率依次为担子菌门、子囊菌门、基础真菌谱系和球囊霉门。群落丰富度和多样性估计值随着深度的增加而降低，这是意料之中的。尽管来自较深剖面的样本的物种丰富度显著降低，但即使采样的最深层也包含了三分之一以上的最上层的丰富度。更重要的是，非参数多维尺度（NMS）排序分析表明，真菌群落在垂直剖面之间存在差异，尽管仅当通过 ANOVA 比较 NMS 轴得分时，最上层和最深层才有显著差异。这些结果强调了考虑垂直地层中真菌群落的重要性，因为较深的土壤层可能具有独特的群落组成，因此对整体丰富度有很大贡献。大多数操作分类单元（OTU）随着深度的增加而减少频率，尽管线性回归分析表明，一些 OTU 随着深度的增加而增加。随着频率增加的 OTU 和 BLAST 分配的分类群主要是不可培养的真菌，但有些与节丛孢科和梨孢科或皮壳菌属有相似的亲缘关系。虽然深层土壤中真菌的生态作用仍不确定，但我们假设，偏好深层土壤的真菌有足够的机会接触到基质，并具有使其在这些环境中生存的环境耐受性。
