title: Coupling Bacterioplankton Populations and Environment to Community Function in Coastal Temperate Waters.
abstract: Bacterioplankton play a key role in marine waters facilitating processes important for carbon cycling. However, the influence of specific bacterial populations and environmental conditions on bacterioplankton community performance remains unclear. The aim of the present study was to identify drivers of bacterioplankton community functions, taking into account the variability in community composition and environmental conditions over seasons, in two contrasting coastal systems. A Least Absolute Shrinkage and Selection Operator (LASSO) analysis of the biological and chemical data obtained from surface waters over a full year indicated that specific bacterial populations were linked to measured functions. Namely,Synechococcus(Cyanobacteria) was strongly correlated with protease activity. Both function and community composition showed seasonal variation. However, the pattern of substrate utilization capacity could not be directly linked to the community dynamics. The overall importance of dissolved organic matter (DOM) parameters in the LASSO models indicate that bacterioplankton respond to the present substrate landscape, with a particular importance of nitrogenous DOM. The identification of common drivers of bacterioplankton community functions in two different systems indicates that the drivers may be of broader relevance in coastal temperate waters.
authors.affiliation: Centre for Ocean Life, Marine Biological Section, University of Copenhagen Helsingør, Denmark.
authors.forename: Sachia J
authors.initials: SJ
authors.lastname: Traving
authors.affiliation: Marine Biological Section, University of Copenhagen Helsingør, Denmark.
authors.forename: Mikkel
authors.initials: M
authors.lastname: Bentzon-Tilia
authors.affiliation: Department of Bioscience, Aarhus University Roskilde, Denmark.
authors.forename: Helle
authors.initials: H
authors.lastname: Knudsen-Leerbeck
authors.affiliation: Department of Bioscience, Aarhus University Roskilde, Denmark.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Mantikci
authors.affiliation: Department of Bioscience, Aarhus University Roskilde, Denmark.
authors.forename: Jørgen L S
authors.initials: JL
authors.lastname: Hansen
authors.affiliation: Centre for Ocean Life, National Institute of Aquatic Resources, Technical University of Denmark Charlottenlund, Denmark.
authors.forename: Colin A
authors.initials: CA
authors.lastname: Stedmon
authors.affiliation: Laboratory for Applied Statistics, Department of Mathematical Sciences, University of Copenhagen Copenhagen, Denmark.
authors.forename: Helle
authors.initials: H
authors.lastname: Sørensen
authors.affiliation: Department of Bioscience, Aarhus University Roskilde, Denmark.
authors.forename: Stiig
authors.initials: S
authors.lastname: Markager
authors.affiliation: Centre for Ocean Life, Marine Biological Section, University of CopenhagenHelsingør, Denmark; Marine Biological Section, University of CopenhagenHelsingør, Denmark.
authors.forename: Lasse
authors.initials: L
authors.lastname: Riemann
keywords: 16S rRNA gene; LASSO analysis; bacterial growth; bacterioplankton communities; coastal ecosystems; community functions; extracellular enzymes; seasonality