Microbial leaf degraders in boreal streams: bringing together stochastic and deterministic regulators ofcommunity composition
2009 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 54, 2276-2289 p.Article in journal (Refereed) Published
1. Leaves that fall into the water represent a new habitat for microorganisms to colonise in streams, providing an opportunity to study colonisation and the subsequent regulation of community structure. We explored community composition of bacteria and fungi on decomposing alder leaves in nine streams in central Sweden, and describe their relationship with environmental variables. Succession of the microbial community was studied in one of the streams for 118 days. Microbial community composition was examined by denaturing gradient gel electrophoresis on replicate samples of leaves from each stream.
2. During succession in one stream, maximum taxon richness was reached after 34 days for bacteria and 20 days for fungi respectively. Replicate samples within this stream differed between each other earlier in colonisation, while subsequently such variation among replicate communities was low and remained stable for several weeks. Replicate samples taken from all the nine streams after 34 days of succession showed striking similarities in microbial communities within-streams, although communities differed more strongly between streams.
3. Canonical analysis of microbial communities and environmental variables revealed that water chemistry had a significant influence on community composition. This influence was superimposed on a statistical relationship between the properties of stream catchments and microbial community composition.
4. The catchment regulates microbial communities in two different ways. It harbours the species pool from which the in-stream microbial community is drawn and it governs stream chemistry and the composition of organic substrates that further shape the communities. We suggest that there is a random element to colonisation early in succession, whereas other factors such as species interactions, stream chemistry and organic substrate properties, result in a more deterministic regulation of communities during later stages.
Place, publisher, year, edition, pages
Wiley-Blackwell, 2009. Vol. 54, 2276-2289 p.
bacteria, community, fungi, leaf litter, succession
IdentifiersURN: urn:nbn:se:liu:diva-65838DOI: 10.1111/j.1365-2427.2009.02257.xISI: 000270613600008OAI: oai:DiVA.org:liu-65838DiVA: diva2:399466