Local factors control the community composition ofcyanobacteria in lakes while heterotrophic bacteriafollow a neutral model
2010 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 55, no 12, 2447-2457 p.Article in journal (Refereed) Published
1. Neutral community models are derived from the proposition that basic probabilities ofspecies loss (extinction, emigration) and gain (immigration, speciation) explain biologicalcommunity structure, such that species with many individuals are very likely to bewidespread. Niche models on the other hand assume that interactions between species anddifferential resource use mediate species coexistence, thus invoking environmental factorsto explain community patterns.2. In this study, we compared neutral and niche models to test how much of the spatialvariability of assemblages of heterotrophic bacteria and phytoplankton in 13 lakes theycould explain. Analysis of phytoplankton was restricted to cyanobacteria, so that theycould be studied with the same molecular fingerprinting method, automated ribosomalintergenic spaces analysis (ARISA), as heterotrophic bacteria. We determined local bioticand abiotic lake variables as well as lake age, glacial history and distance between sites.3. The neutral community model had a good fit to the community composition ofheterotrophic bacteria (R2 = 0.69), whereas it could not produce a significant model for thecommunity composition of cyanobacteria.4. The community composition of cyanobacteria was instead correlated to environmentalvariables. The best model, a combination of total organic carbon, biomass of eukaryoticphytoplankton, pH and conductivity, could explain 8% of the variation. In contrast,variation in the community composition of heterotrophic bacteria was not predicted byany of the environmental variables. Historical and spatial variables were not correlated tothe community composition of either group.5. The pattern found for heterotrophic bacteria suggests that stochastic processes areimportant. The correlation of cyanobacteria with local environmental variables alone isconsistent with the niche model. We suggest that cyanobacteria, a group of organismscontaining bloom-forming species, may be less likely to fit a neutral community model,since these blooms are usually triggered by a particular combination of environmentalconditions.Keywords: automated
Place, publisher, year, edition, pages
2010. Vol. 55, no 12, 2447-2457 p.
automated ribosomal intergenic spacer analysis, cyanobacteria, environmental factors, heterotrophic bacteria, neutral model
IdentifiersURN: urn:nbn:se:umu:diva-38688DOI: 10.1111/j.1365-2427.2010.02473.xOAI: oai:DiVA.org:umu-38688DiVA: diva2:380514