Bacterial metacommunity organization in a highly connected aquatic system.
The spatial structure and underlying assembly mechanisms of bacterial communities have been studied widely across aquatic systems, focusing primarily on isolated sites, such as different lakes, ponds and streams. Here, our main aim was to determine the underlying mechanisms for bacterial biofilm assembly within a large, highly connected lake system in Northern Finland using associative methods based on taxonomic and phylogenetic alpha- and beta-diversity and a large number of abiotic and biotic variables. Furthermore, null model approaches were used to quantify the relative importance of different community assembly processes. We found that spatial variation in bacterial communities within the lake was structured by different assembly processes, including stochasticity, species sorting and potentially even dispersal limitation. Species sorting by abiotic environmental conditions explained more of the taxonomic and particularly phylogenetic turnover in community composition compared with that by biotic variables. Finally, we observed clear differences in alpha diversity (species richness and phylogenetic diversity), which were to a stronger extent determined by abiotic compared with biotic factors, but also by dispersal effects. In summary, our study shows that the biodiversity of bacterial biofilm communities within a lake ecosystem is driven by within-habitat gradients in abiotic conditions and by stochastic and deterministic dispersal processes.
Department of Ecology and Genetics/Limnology and Erken Laboratory, Uppsala University, Sweden.
Silke
S
Langenheder
Department of Geosciences and Geography, University of Helsinki, Helsinki FIN-00014, Finland.|State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academic of Sciences, Nanjing 210008, China.
Jianjun
J
Wang
Finnish Environment Institute, Freshwater Centre, FI-90570 Oulu, Finland.
Satu Maaria
SM
Karjalainen
Finnish Environment Institute, Freshwater Centre, FI-90570 Oulu, Finland.
Tiina M
TM
Laamanen
Finnish Environment Institute, Natural Environment Centre, Biodiversity, FI-90570 Oulu, Finland.
Kimmo T
KT
Tolonen
Finnish Environment Institute, Natural Environment Centre, Biodiversity, FI-90570 Oulu, Finland.
Annika
A
Vilmi
Finnish Environment Institute, Natural Environment Centre, Biodiversity, FI-90570 Oulu, Finland.
Jani
J
Heino
D001419:Bacteria / Q000145:classification*; D044822:Biodiversity; D018441:Biofilms / Q000145:classification*; D017753:Ecosystem; D005387:Finland; D060106:Lakes / Q000382:microbiology*; D059013:Microbial Consortia / Q000502:physiology*; D010802:Phylogeny; D045483:Rivers / Q000382:microbiology*