Determining the Influence of Environmental Factors upon Dominant Soil Bacterial Taxa and Functioning

确定环境因素对主要土壤细菌类群及其功能的影响

• 批准号: NE/E012140/1
• 负责人: Andrew Whiteley
• 金额: $ 43.07万
• 依托单位: NERC CEH (Up to 30.11.2019)
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FE012140%2F1
• 关键词: Determining; Influence; Environmental; Factors; upon

Bacteria constitute a major portion of the biodiversity and biomass in soils and consequently they play an essential role in maintaining soil processes which, ultimately, regulate the functioning of terrestrial ecosystems. The use of molecular techniques has permitted a greater understanding of the identities of dominant bacteria present in a range of soil types, though there is still a lack of understanding as to what drives this diversity on a large geographic scale. In addition, there is no clear consensus on how alterations in bacterial biodiversity impacts on ecosystem functions such as the mineralization of carbon. Such knowledge is essential to improving our understanding of the controlling factors behind a range of soil processes, and in addition may provide a fundamental framework for the future use of biological indicators of soil quality. Recently it has been shown that pH is the main driver in determining the richness of bacterial taxa in soil communities, and additionally there is an emerging hypothesis that the nutrient status of the soil dictates the ratio of two abundant groups of soil taxa. We aim to disentangle this relationship in a diverse range of soil types. Specifically we seek to firstly asses the role of pH in determining the identities of dominant soil bacteria, and then we will address how different nutrient inputs determined by aboveground vegetation, and additional environmental variables affect soil bacterial biodiversity. We will do this by assessing all soil samples taken as part of the Countryside Survey (CS) 2007. These soil samples will be thoroughly characterised with respect to soil chemistry and overlying vegetation as a core element of the Countryside Survey. Using these soils will allow us to correlate several key soil variables with specific changes in members of the bacterial community. Whilst we wish to address fundamental questions on the controls of soil bacterial community diversity, we also seek to question the usefulness of microbial indicators of soil functionality. Therefore, once taxonomic relationships have been established, we will select subsets of samples purely on the basis of similarity of bacterial composition/diversity, and measure carbon mineralization rates to determine whether communities of similar bacterial diversity confer similar functional abilities.

细菌是土壤生物多样性和生物量的主要组成部分，因此它们在维持土壤过程中发挥着至关重要的作用，最终调节陆地生态系统的功能。分子技术的使用使人们能够更好地了解存在于一系列土壤类型中的优势细菌的身份，尽管仍然缺乏对在大的地理范围内驱动这种多样性的原因的了解。此外，关于细菌生物多样性的改变如何影响生态系统功能（如碳的矿化），目前还没有明确的共识。这些知识对于提高我们对一系列土壤过程背后的控制因素的理解至关重要，此外还可以为未来使用土壤质量生物指标提供基本框架。最近已经表明，pH值是决定土壤群落中细菌类群丰富度的主要驱动因素，此外还有一种新的假设，即土壤的营养状况决定了两种丰富的土壤类群的比例。我们的目标是在不同的土壤类型中解开这种关系。具体来说，我们寻求首先评估pH值的作用，在确定的身份占主导地位的土壤细菌，然后我们将解决如何不同的营养输入确定地上植被，以及其他环境变量影响土壤细菌的生物多样性。我们会评估在2007年乡郊统计调查中抽取的所有泥土样本，以达致上述目的。这些土壤样本将在土壤化学和覆盖植被方面进行彻底的特征分析，作为郊区调查的核心内容。使用这些土壤将使我们能够将几个关键的土壤变量与细菌群落成员的特定变化相关联。虽然我们希望解决土壤细菌群落多样性控制的基本问题，我们也试图质疑土壤功能的微生物指标的有用性。因此，一旦建立了分类学关系，我们将纯粹基于细菌组成/多样性的相似性来选择样本子集，并测量碳矿化率，以确定相似细菌多样性的群落是否具有相似的功能能力。