Microbial community composition in sediments resists perturbation by nutrient enrichment
Jennifer L Bowen1, Bess B Ward, Hilary G Morrison
1The Ecosystems Center, Marine Biological Laboratory, Woods Hole, MA, USA. jennifer.bowen@umb.edu
The ISME Journal
|March 18, 2011
Summary
Microbial communities in salt marsh sediments demonstrated resistance to nutrient enrichment, maintaining stable composition despite ecological changes. This suggests a decoupling between microbial communities and ecosystem processes, highlighting their resilience to perturbation.
Area of Science:
- Microbial Ecology
- Environmental Science
- Ecosystem Dynamics
Background:
- Functional redundancy is theorized to enable microbial community stability during disturbances.
- However, recent studies indicate that microbial communities can alter both composition and function following disturbances.
- This study investigates an alternative response: resistance.
Purpose of the Study:
- To examine the response of microbial communities in salt marsh sediments to nutrient enrichment.
- To determine if microbial community composition changes with nutrient supply.
- To assess the relationship between microbial community structure and ecosystem-level biogeochemical processes.
Main Methods:
- Deep pyrosequencing of 16S rRNA genes to analyze bacterial community composition.
- Functional gene microarrays targeting the nirS gene for functional analysis.
- Sampling of salt marsh sediments under varying nutrient enrichment conditions.
Main Results:
- Microbial community composition, assessed by both 16S rRNA and nirS gene analysis, remained unaffected by significant external nutrient supply variations.
- Nutrient enrichment induced demonstrable and diverse changes in other aspects of marsh ecology.
- A notable uncoupling was observed between microbial community composition and ecosystem-level biogeochemical processes.
Conclusions:
- Sediment microbial communities in salt marshes exhibit resistance to nutrient enrichment perturbation.
- The stability of microbial composition suggests resilience independent of external nutrient forcing.
- This resistance indicates a significant uncoupling between microbial community structure and broader ecosystem functions.
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