Microbial communities display biogeographical patterns that are driven by local environmental conditions and dispersal limitation, but the relative importance of underlying dispersal mechanisms and their consequences on community structure are not well described. High dispersal rates can cause soil microbial communities to become more homogenous across space and therefore it is important to identify factors that promote dispersal. This study experimentally manipulated microbial dispersal within different land management treatments at a native tallgrass prairie site, by changing the relative openness of soil to dispersal and by simulating vector dispersal via bison dung addition. We deployed experimental soil bags with mesh open or closed to dispersal, and placed bison dung over a subset of these bags, to areas with three different land managements: active bison grazing and annual fire, annual fire but no bison grazing, and no bison grazing with infrequent fire. We expected microbial dispersal to be highest in grazed and burned environments, and that the addition of dung would consistently increase overall microbial richness and lead to homogenization of communities over time. Results show that dispersal rates, as the accumulation of taxa over the course of the 3-month experiment, increase taxonomic richness similarly in all land management treatments. Additionally, bison dung seems to be serving as a dispersal and homogenization vector, based on the consistently higher taxon richness and increased community similarity across contrasting grazing and fire treatments when dung is added. This finding also points to microbial dispersal as an important function that herbivores perform in grassland ecosystems, and in turn, as a function that was lost at a continental scale following bison extermination across the Great Plains of North America in the nineteenth century. This study is the first to detect that dispersal and vector dispersal by grazing mammals promote grassland soil microbial diversity and affect microbial community composition.
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Microbial Ecology Meets Macroecology: Developing a Process‐Based Understanding of the Microbial Role in Global Ecosystems
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For over a century, environmental engineers have attempted to control the prokaryotic community biological wastewater treatment processes, but there is growing interest in both understanding and harnessing the activity of phages in wastewater bioprocesses. While phages are known to be present and abundant, their ecological role, potential benefits, and impacts on wastewater biological processes are not fully understood. Fundamental knowledge on how phages infect host cells from relatively simple pure culture studies alongside environmental studies from marine and soil systems can be used to predict the potential impact of phages in diverse and dynamic wastewater environments. This frontier review is focused on what is known about the molecular mechanisms by which phages infect bacteria and how that could apply to biological process control and operation within wastewater treatment systems. Here, we specifically focus on highlights from studies on the molecular mechanisms that drive lysis and lysogeny within phage cells and the impacts on the dissemination of antibiotic resistance genes and nutrient removal within a biological wastewater process.more » « less
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/bes2.1645
