Toward an ecological classification of soil bacteria
Toward an ecological classification of soil bacteria
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DOI：
10.1890/05-1839
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发表时间：
2007-06-01
期刊：
影响因子：
4.8
通讯作者：
Jackson, Robert B.
中科院分区：
文献类型：
--
作者：
Fierer, Noah;Bradford, Mark A.;Jackson, Robert B.
尽管研究人员已经开始对土壤中发现的细菌的多样性进行编目，但我们在很大程度上无法在生态背景下解释这些信息，包括哪些细菌群在不同土壤中最丰富以及为什么。通过这项研究，我们研究了主要土壤细菌门的丰度如何对应于土壤环境的生物和非生物特征，以确定它们是否可以被划分为具有生态意义的类别。为了做到这一点，我们收集了71个独特的土壤样本，从广泛的生态系统在北美和寻找土壤性质和相对丰度的六个主要细菌门（酸细菌，拟杆菌，厚壁菌门，放线菌，α-变形菌，β-变形菌）之间的关系。在所测的土壤性质中，净碳矿化率（碳有效性的一个指标）是最能预测植物门水平丰度的指标。酸性细菌丰度与C矿化率呈负相关（r（2）= 20.26，P < 0.001），β-变形菌和拟杆菌丰度与C矿化率呈正相关（r（2）= 0.35，P < 0.001和r（2）= 0.34，P < 0.001）。这些模式进一步探索使用实验和荟萃分析方法。我们修改了土壤芯从一个特定的网站与不同水平的蔗糖在12个月的时间内，以保持梯度升高的C的可用性。本实验证实了我们的调查结果：C添加水平与酸细菌的丰度呈负相关（r（2）= 0.42，P < 0.01），拟杆菌和β-变形菌的丰度呈正相关（r（2）分别为0.38和0.70，P均< 0.01）。这些细菌门和C的可用性的相对丰度之间的关系的进一步支持，获得从散装和根际土壤的已发表的细菌克隆库的分析。我们的调查，实验和荟萃分析的结果表明，某些细菌门可以区分为共生和寡营养类别，对应于用于描述植物和动物的生态属性的r-和K-选择的类别。通过将共生-寡养概念应用于土壤微生物，我们可以对各种细菌类群的生态属性进行具体预测，并更好地了解土壤细菌群落的结构和功能。
Although researchers have begun cataloging the incredible diversity of bacteria found in soil, we are largely unable to interpret this information in an ecological context, including which groups of bacteria are most abundant in different soils and why. With this study, we examined how the abundances of major soil bacterial phyla correspond to the biotic and abiotic characteristics of the soil environment to determine if they can be divided into ecologically meaningful categories. To do this, we collected 71 unique soil samples from a wide range of ecosystems across North America and looked for relationships between soil properties and the relative abundances of six dominant bacterial phyla (Acidobacteria, Bacteroidetes, Firmicutes, Actinobacteria, alpha-Proteobacteria, and the beta-Proteobacteria). Of the soil properties measured, net carbon (C) mineralization rate (an index of C availability) was the best predictor of phylum-level abundances. There was a negative correlation between Acidobacteria abundance and C mineralization rates (r(2) = 2 0.26, P < 0.001), while the abundances of beta-Proteobacteria and Bacteroidetes were positively correlated with C mineralization rates (r(2) = 0.35, P < 0.001 and r(2) = 0.34, P < 0.001, respectively). These patterns were explored further using both experimental and meta-analytical approaches. We amended soil cores from a specific site with varying levels of sucrose over a 12-month period to maintain a gradient of elevated C availabilities. This experiment confirmed our survey results: there was a negative relationship between C amendment level and the abundance of Acidobacteria (r(2) = 0.42, P < 0.01) and a positive relationship for both Bacteroidetes and beta-Proteobacteria (r(2) = 0.38 and 0.70, respectively; P < 0.01 for each). Further support for a relationship between the relative abundances of these bacterial phyla and C availability was garnered from an analysis of published bacterial clone libraries from bulk and rhizosphere soils. Together our survey, experimental, and meta-analytical results suggest that certain bacterial phyla can be differentiated into copiotrophic and oligotrophic categories that correspond to the r- and K-selected categories used to describe the ecological attributes of plants and animals. By applying the copiotroph-oligotroph concept to soil microorganisms we can make specific predictions about the ecological attributes of various bacterial taxa and better understand the structure and function of soil bacterial communities.