| 1. |
- Östman, Örjan, et al.
(författare)
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Importance of space and the local environment for linking local and regional abundances of microbes
- 2012
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Ingår i: Aquatic Microbial Ecology. - : Inter-Research Science Center. - 0948-3055 .- 1616-1564. ; 67:1, s. 35-158
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Tidskriftsartikel (refereegranskat)abstract
- It is frequently observed that the local relative abundances of aquatic microbial taxa are correlated with their average relative abundance at the regional scale, which results in the composition of different communities being more similar than expected by chance or invariant. The degree to which communities within a region match the regional average community is variable and likely depends on several different mechanisms that control the process of microbial community assembly. Here, we show that environmental variables were associated with the community specific degree of regional invariance in 9 of 10 datasets of microbial communities in aquatic systems, being the main set of variables explaining differences in regional invariance in 5 of them. This indicates that variation in local environmental conditions across a region reduces the degree of regional invariance amongst communities. Spatial distances between communities were not related to the degrees of regional invariance, but in 7 of the datasets, regional invariance differed among different parts of the regions, particularly for phytoplankton communities. This suggests an influence of spatial or historical processes on the community specific degree of regional invariance. We conclude that both local environmental conditions and spatial/historical processes cause between-site differences in the degree of invariance between local and regional abundances in aquatic microbial metacommunities. We argue that studies of regional invariance can be an important complement to other statistical methods due to its propensity to detect variation in stochastic processes along gradients.
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| 2. |
- Östman, Örjan, et al.
(författare)
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Regional invariance among microbial communities
- 2010
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 13:1, s. 118-127
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Tidskriftsartikel (refereegranskat)abstract
- Microbial ecology has focused much on causes of between-site variation in community composition. By analysing five data-sets each of aquatic bacteria and phytoplankton, we demonstrated that microbial communities show a large degree of similarity in community composition and that abundant taxa were widespread, a typical pattern for many metazoan metacommunities. The regional abundance of taxa explained on average 85 and 41% of variation in detection frequency and 58 and 31% of variation in local abundances for bacteria and phytoplankton, respectively. However, regional abundance explained less variation in local abundances with increasing environmental variation between sites within data-sets. These findings indicate that the studies of microbial assemblages need to consider similarities between communities to better understand the processes underlying the assembly of microbial communities. Finally, we propose that the degree of regional invariance can be linked to the evolution of microbes and the variation in ecosystem functions performed by microbial communities.
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