Microbial Biodiversity in Groundwater Ecosystems

Abstract

This chapter discusses the relevance of microbial biodiversity in the groundwater environment. We provide information on the general methodological approaches that are used to estimate the microbial diversity. The importance of biodiversity as an inherent value of an ecosystem and its implication for ecosystem functioning is highlighted. We provide insight on the spatial and temporal scales of microbial diversity, which can span several orders of magnitude in aquifers. Relevant groundwater taxa and groundwater habitats are presented in terms of case studies that illustrate the breadth of ongoing research. Finally, the chapter discusses the knowledge gaps and potential for microbial diversity research in groundwater. Main concepts covered: Microbial diversity connects genetic variance, species biodiversity up to the ecosystem level. We delineate the biotic and abiotic conditions, which are the driving and limiting factors of biodiversity. Consequently, we discuss the effect of varying spatial scales and how to compare intra-and inter-community diversity as well as total diversity of a landscape. The intrinsic and utilitarian value of microbial biodiversity in groundwater habitats is presented in terms of ecosystem functioning. We cover the concepts of ecosystem stability and functional redundancy. Main methods covered: The methods covered in this chapter include a brief discussion of the molecular tools that are used to characterize the microbial diversity in groundwater. We highlight the main advantages of new sequencing techniques which work at unprecedented sensitivity and speed. Therefore, we stress the importance of bioinformatic and statistical analysis combined with a thoughtful experimental design. Conclusion/Outlook: The groundwater environment is a vital link for terrestrial and aquatic ecosystems. The microbial biodiversity in the subsurface is a critical factor for ecosystem services, but remains a frontier of ecological research.