Environmental controls over bacterial communities in polar desert soils
Environmental controls over bacterial communities in polar desert soils
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DOI：
10.1890/es13-00048.1
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发表时间：
2013-10-01
期刊：
影响因子：
2.7
通讯作者：
Barrett, J. E.
中科院分区：
文献类型：
--
作者：
Geyer, Kevin M.;Altrichter, Adam E.;Barrett, J. E.
事实证明，生产力多样性理论对于许多旨在了解生物群落空间模式驱动因素以及各种类群记录的资源可用性和群落结构之间关系的研究提供了丰富的信息。对于土壤细菌来说，有机质的可用性是一种已知会影响多样性和群落结构的资源。在这里，我们描述了环境梯度对南极洲麦克默多干谷土壤细菌群落的影响，这是一个模型生态系统，拥有简单的、以微生物为主的食物网，据信主要由水、有机质、pH 和电导率等非生物驱动因素构成。我们对 48 个地点进行了采样，这些地点在当地和区域范围内的初级生产和土壤地球化学（pH 值和电导率）表现出数量级的范围。我们的研究结果表明，隐花生产力和地球化学区域差异所造成的环境梯度影响土壤细菌群落的多样性和结构。土壤细菌丰富度对碳含量的响应说明了生产力与多样性的关系，而细菌群落结构主要对土壤 pH 值和电导率做出响应。这种对资源可用性的多样性响应和对环境严重性的群落结构响应表明，需要仔细考虑微生物群落和相关功能如何响应人类活动和气候变化引起的环境条件变化。
Productivity-diversity theory has proven informative to many investigations seeking to understand drivers of spatial patterns in biotic communities and relationships between resource availability and community structure documented for a wide variety of taxa. For soil bacteria, availability of organic matter is one such resource known to influence diversity and community structure. Here we describe the influence of environmental gradients on soil bacterial communities of the McMurdo Dry Valleys, Antarctica, a model ecosystem that hosts simple, microbially-dominated foodwebs believed to be primarily structured by abiotic drivers such as water, organic matter, pH, and electrical conductivity. We sampled 48 locations exhibiting orders of magnitude ranges in primary production and soil geochemistry (pH and electrical conductivity) over local and regional scales. Our findings show that environmental gradients imposed by cryptogam productivity and regional variation in geochemistry influence the diversity and structure of soil bacterial communities. Responses of soil bacterial richness to carbon content illustrate a productivity-diversity relationship, while bacterial community structure primarily responds to soil pH and electrical conductivity. This diversity response to resource availability and a community structure response to environmental severity suggests a need for careful consideration of how microbial communities and associated functions may respond to shifting environmental conditions resulting from human activity and climate variability.