title: Spatial structure leads to ecological breakdown and loss of diversity.
abstract: Spatial structure has been identified as a major contributor to the maintenance of diversity. Here, we show that the impact of spatial structure on diversity is strongly affected by the ecological mechanisms maintaining diversity. In well-mixed, unstructured environments, microbial populations can diversify by production of metabolites during growth, providing additional resources for novel specialists. By contrast, spatially structured environments potentially limit such facilitation due to reduced metabolite diffusion. Using replicate microcosms containing the bacterium Escherichia coli, we predicted the loss of diversity during an environmental shift from a spatially unstructured environment to spatially structured conditions. Although spatial structure is frequently observed to be a major promoter of diversity, our results indicate that it can also have negative impacts on diversity.
authors.affiliation: Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4. gsaxer@rice.edu
authors.forename: Gerda
authors.initials: G
authors.lastname: Saxer
authors.forename: Michael
authors.initials: M
authors.lastname: Doebeli
authors.forename: Michael
authors.initials: M
authors.lastname: Travisano