Wang Xiaobo, Van Nostrand Joy D, Deng Ye, Lü Xiaotao, Wang Chao, Zhou Jizhong, Han Xingguo
State Key Laboratory of Forest and Soil Ecology, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, PR China University of Chinese Academy of Sciences, Beijing 100049, PR China Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK 73019, USA.
Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, OK 73019, USA.
FEMS Microbiol Ecol. 2015 Dec;91(12). doi: 10.1093/femsec/fiv133. Epub 2015 Oct 29.
Patterns of variation in plant and animal diversity along precipitation gradients have been extensively studied, but much less is known about how and to what extent precipitation affects the biogeographic distribution of microbial diversity in arid areas across large spatial scales. Here we collected soils from 54 sites along a 3700 km transect covering a wide range of grassland ecosystems with distinct aridity gradients. We quantified the bacterial community diversity and the effects of climate, edaphic parameter and geographic distance on the bacterial community structure using high-throughput 16S rRNA gene sequencing. Of the 35 phyla detected, 6 were dominant: Actinobacteria, Acidobacteria, Alphaproteobacteria, Deltaproteobacteria, Bacteroidetes and Planctomycetes. Aridity was a major factor influencing bacterial diversity, community composition and taxon abundance. Although the pattern of bacterial species richness is markedly different from that of plant species richness, most soil bacteria were endemic to particular bioregions like macro-organisms. Community similarity significantly declined with environmental distance and geographic distance (r = -0.579 and -0.773, respectively). Geographic distance (historical contingencies) contributed more to bacterial community variation (36.02%) than combined environmental factors (24.06%). Overall, our results showed that geographic distance and climatic factors concurrently govern bacterial biogeographic patterns in arid and semi-arid grassland.
植物和动物多样性沿降水梯度的变化模式已得到广泛研究，但对于降水如何以及在多大程度上影响大空间尺度干旱地区微生物多样性的生物地理分布，我们知之甚少。在这里，我们沿着一条3700公里的样带，从54个地点采集了土壤，该样带覆盖了广泛的具有不同干旱梯度的草原生态系统。我们使用高通量16S rRNA基因测序技术，对细菌群落多样性以及气候、土壤参数和地理距离对细菌群落结构的影响进行了量化。在检测到的35个门中，有6个是优势门：放线菌门、酸杆菌门、α-变形菌纲、δ-变形菌纲、拟杆菌门和浮霉菌门。干旱是影响细菌多样性、群落组成和分类单元丰度的主要因素。虽然细菌物种丰富度模式与植物物种丰富度模式明显不同，但大多数土壤细菌像大型生物一样，是特定生物区域特有的。群落相似性随环境距离和地理距离显著下降（分别为r = -0.579和-0.773）。地理距离（历史偶然性）对细菌群落变异的贡献（36.02%）大于综合环境因素（24.06%）。总体而言，我们的结果表明，地理距离和气候因素共同控制着干旱和半干旱草原的细菌生物地理模式。
