Dispersal-Based Microbial Community Assembly Decreases Biogeochemical Function
AbstractEcological mechanisms influence relationships among microbial communities, which in turn impact biogeochemistry. In particular, microbial communities are assembled by deterministic (e.g., selection) and stochastic (e.g., dispersal) processes, and the relative balance of these two process types is hypothesized to alter the influence of microbial communities over biogeochemical function. We used an ecological simulation model to evaluate this hypothesis, defining biogeochemical function generically to represent any biogeochemical reaction of interest. We assembled receiving communities under different levels of dispersal from a source community that was assembled purely by selection. The dispersal scenarios ranged from no dispersal (i.e., selection-only) to dispersal rates high enough to overwhelm selection (i.e., homogenizing dispersal). We used an aggregate measure of community fitness to infer a given community’s biogeochemical function relative to other communities. We also used ecological null models to further link the relative influence of deterministic assembly to function. We found that increasing rates of dispersal decrease biogeochemical function by increasing the proportion of maladapted taxa in a local community. Niche breadth was also a key determinant of biogeochemical function, suggesting a tradeoff between the function of generalist and specialist species. Finally, we show that microbial assembly processes exert greater influence over biogeochemical function when there is variation in the relative contributions of dispersal and selection among communities. Taken together, our results highlight the influence of spatial processes on biogeochemical function and indicate the need to account for such effects in models that aim to predict biogeochemical function under future environmental scenarios. View Full-Text
A printed edition of this Special Issue is available here.
Share & Cite This Article
Graham, E.B.; Stegen, J.C. Dispersal-Based Microbial Community Assembly Decreases Biogeochemical Function. Processes 2017, 5, 65.
Graham EB, Stegen JC. Dispersal-Based Microbial Community Assembly Decreases Biogeochemical Function. Processes. 2017; 5(4):65.Chicago/Turabian Style
Graham, Emily B.; Stegen, James C. 2017. "Dispersal-Based Microbial Community Assembly Decreases Biogeochemical Function." Processes 5, no. 4: 65.
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.