| 1. |
- Langenheder, Silke, et al.
(författare)
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Bacterial biodiversity-ecosystem function relations are modified by environmental complexity
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:5, s. e10834-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundWith the recognition that environmental change resulting from anthropogenic activities is causing a global decline in biodiversity, much attention has been devoted to understanding how changes in biodiversity may alter levels of ecosystem functioning. Although environmental complexity has long been recognised as a major driving force in evolutionary processes, it has only recently been incorporated into biodiversity-ecosystem functioning investigations. Environmental complexity is expected to strengthen the positive effect of species richness on ecosystem functioning, mainly because it leads to stronger complementarity effects, such as resource partitioning and facilitative interactions among species when the number of available resource increases.Methodology/Principal FindingsHere we implemented an experiment to test the combined effect of species richness and environmental complexity, more specifically, resource richness on ecosystem functioning over time. We show, using all possible combinations of species within a bacterial community consisting of six species, and all possible combinations of three substrates, that diversity-functioning (metabolic activity) relationships change over time from linear to saturated. This was probably caused by a combination of limited complementarity effects and negative interactions among competing species as the experiment progressed. Even though species richness and resource richness both enhanced ecosystem functioning, they did so independently from each other. Instead there were complex interactions between particular species and substrate combinations.Conclusions/SignificanceOur study shows clearly that both species richness and environmental complexity increase ecosystem functioning. The finding that there was no direct interaction between these two factors, but that instead rather complex interactions between combinations of certain species and resources underlie positive biodiversity ecosystem functioning relationships, suggests that detailed knowledge of how individual species interact with complex natural environments will be required in order to make reliable predictions about how altered levels of biodiversity will most likely affect ecosystem functioning.
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| 2. |
- Langenheder, Silke, et al.
(författare)
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Role of functionally dominant species in varying environmental regimes : evidence for the performance-enhancing effect of biodiversity
- 2012
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Ingår i: BMC Ecology. - : Springer Science and Business Media LLC. - 1472-6785. ; 12, s. 14-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Theory suggests that biodiversity can act as a buffer against disturbances and environmental variability via two major mechanisms: Firstly, a stabilising effect by decreasing the temporal variance in ecosystem functioning due to compensatory processes; and secondly, a performance enhancing effect by raising the level of community response through the selection of better performing species. Empirical evidence for the stabilizing effect of biodiversity is readily available, whereas experimental confirmation of the performance-enhancing effect of biodiversity is sparse. Results: Here, we test the effect of different environmental regimes (constant versus fluctuating temperature) on bacterial biodiversity-ecosystem functioning relations. We show that positive effects of species richness on ecosystem functioning are enhanced by stronger temperature fluctuations due to the increased performance of individual species. Conclusions: Our results provide evidence for the performance enhancing effect and suggest that selection towards functionally dominant species is likely to benefit the maintenance of ecosystem functioning under more variable conditions.
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| 3. |
- Philippot, Laurent, et al.
(författare)
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The ecological coherence of high bacterial taxonomic ranks
- 2010
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Ingår i: Nature Reviews Microbiology. - : Springer Science and Business Media LLC. - 1740-1526 .- 1740-1534. ; 8:7, s. 523-529
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Forskningsöversikt (refereegranskat)abstract
- The species is a fundamental unit of biological organization, but its relevance for Bacteria and Archaea is still hotly debated. Even more controversial is whether the deeper branches of the ribosomal RNA-derived phylogenetic tree, such as the phyla, have ecological importance. Here, we discuss the ecological coherence of high bacterial taxa in the light of genome analyses and present examples of niche differentiation between deeply diverging groups in terrestrial and aquatic systems. The ecological relevance of high bacterial taxa has implications for bacterial taxonomy, evolution and ecology.
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