Altitudinal patterns of diversity and functional traits of metabolically active microorganisms in stream biofilms

Author(s)
Linda Wilhelm, Katharina Besemer, Lena Fragner, Hannes Markus Peter, Wolfram Weckwerth, Tom Battin
Abstract

Resources structure ecological communities and potentially link biodiversity to energy flow. It is commonly believed that functional traits (generalists versus specialists) involved in the exploitation of resources depend on resource availability and environmental fluctuations. The longitudinal nature of stream ecosystems provides changing resources to stream biota with yet unknown effects on microbial functional traits and community structure. We investigated the impact of autochthonous (algal extract) and allochthonous (spruce extract) resources, as they change along alpine streams from above to below the treeline, on microbial diversity, community composition and functions of benthic biofilms. Combining bromodeoxyuridine labelling and 454 pyrosequencing, we showed that diversity was lower upstream than downstream of the treeline and that community composition changed along the altitudinal gradient. We also found that, especially for allochthonous resources, specialisation by biofilm bacteria increased along that same gradient. Our results suggest that in streams below the treeline biofilm diversity, specialisation and functioning are associated with increasing niche differentiation as potentially modulated by divers allochthonous and autochthonous constituents contributing to resources. These findings expand our current understanding on biofilm structure and function in alpine streams.

Organisation(s)
Functional and Evolutionary Ecology
External organisation(s)
University of Glasgow, Leopold-Franzens-Universität Innsbruck, École polytechnique fédérale de Lausanne
Journal
The ISME Journal: multidisciplinary journal of microbial ecology
Volume
9
Pages
2454-2464
No. of pages
11
ISSN
1751-7362
DOI
https://doi.org/10.1038/ismej.2015.56
Publication date
11-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
106020 Limnology, 106022 Microbiology
ASJC Scopus subject areas
Ecology, Evolution, Behavior and Systematics, Microbiology
Portal url
https://ucrisportal.univie.ac.at/en/publications/63a74b66-cfbe-45ad-9dd1-39747cad6494