英国的一个联合研究小组日前宣布，他们成功绘制了英国首张土壤细菌分布图，该图对英国土壤中的微生物进行了迄今为止最为全面和详尽的测定。相关论文发表在当日出版的《环境微生物学》杂志上。
该研究小组由来自英国生态与水文学中心、纽卡斯尔大学和牛津大学的多名科学家组成。研究人员对采集自英格兰、苏格兰以及威尔士的1000份土壤钻孔样本进行检测、分析并绘制出了这幅土壤细菌分布图。研究显示，细菌多样性程度与土壤pH值密切相关，地下菌落和地面植物群落之间也存在着极为密切的关联。细菌是土壤多样性的主要组成部分，在维持土壤健康方面发挥着重要作用，对种植业发展和固碳都有着十分重要的意义。
论文第一作者、英国生态与水文学中心的罗伯特·格里菲斯博士说：“迄今为止我们对细菌群落差异性的认识在整体上还十分有限。新的研究首次在宏观上对英国土壤细菌群落的分布状况进行了描述，为此后土壤细菌多样性以及土壤生态系统等更为复杂的研究奠定了基础。”
另一研究人员安迪·怀特利教授说：“外出散步时，我们绝大多数人都不会注意到脚下那些只有通过显微镜才能看到的细菌，但它们的数量和作用实际上都十分惊人：一个脚印大的一块土壤中就有将近100亿个细菌，它们在保持土壤肥力、维持地球温室气体循环方面均发挥着不可替代的作用。新研究中我们试图揭开地表中这些视野之外的微型群落，并以此来弄清菌群以怎样的方式存在以及为什么要这样，它们在人类生活中发挥着怎样的作用。”
论文的另一位合著者马克·贝利说：“英国生态与水文学中心曾在1996年时绘制了英国首张洪水风险地图。15年后，我们又绘制了世界首张土壤微生物分布地图。从今年开始我们将把部分土壤样品和原始数据提供给更多研究人员，以让它们发挥出更大的研究价值。”
此外，本次实验中所使用的部分土壤样品和细菌DNA还将被作为历史资料冷冻保存下来，以方便未来的研究人员研究气候变化对土壤细菌多样性的影响。（生物谷Bioon.com）
生物谷推荐原文出处：
Environmental Microbiology DOI: 10.1111/j.1462-2920.2011.02480.x
The bacterial biogeography of British soils
Robert I. Griffiths1,*, Bruce C. Thomson1, Phillip James1,2, Thomas Bell3, Mark Bailey1, Andrew S. Whiteley1
Summary
Despite recognition of the importance of soil bacteria to terrestrial ecosystem functioning there is little consensus on the factors regulating belowground biodiversity. Here we present a multi-scale spatial assessment of soil bacterial community profiles across Great Britain (> 1000 soil cores), and show the first landscape scale map of bacterial distributions across a nation. Bacterial diversity and community dissimilarities, assessed using terminal restriction fragment length polymorphism, were most strongly related to soil pH providing a large-scale confirmation of the role of pH in structuring bacterial taxa. However, while diversity was positively related to pH, the converse was true for β diversity (between sample variance in diversity). β diversity was found to be greatest in acidic soils, corresponding with greater environmental heterogeneity. Analyses of clone libraries revealed the pH effects were predominantly manifest at the level of broad bacterial taxonomic groups, with acidic soils being dominated by few taxa (notably the group 1 Acidobacteria and Alphaproteobacteria). We also noted significant correlations between bacterial communities and most other measured environmental variables (soil chemistry, aboveground features and climatic variables), together with significant spatial correlations at close distances. In particular, bacterial and plant communities were closely related signifying no strong evidence that soil bacteria are driven by different ecological processes to those governing higher organisms. We conclude that broad scale surveys are useful in identifying distinct soil biomes comprising reproducible communities of dominant taxa. Together these results provide a baseline ecological framework with which to pursue future research on both soil microbial function, and more explicit biome based assessments of the local ecological drivers of bacterial biodiversity.
