title: Impact of sampling depth and plant species on local environmental conditions, microbiological parameters and bacterial composition in a mercury contaminated salt marsh.
abstract: We compare the environmental characteristics and bacterial communities associated with two rushes, Juncus maritimus and Bolboschoenus maritimus, and adjacent unvegetated habitat in a salt marsh subjected to historical mercury pollution. Mercury content was higher in vegetated than unvegetated habitat and increased with sampling depth. There was also a significant relationship between mercury concentration and bacterial composition. Habitat (Juncus, Bolboschoenus or unvegetated), sample depth, and the interaction between both, however, explained most of the variation in composition (~70%). Variation in composition with depth was most prominent for the unvegetated habitat, followed by Juncus, but more constrained for Bolboschoenus habitat. This constraint may be indicative of a strong plant-microbe ecophysiological adaptation. Vegetated habitat contained distinct bacterial communities associated with higher potential activity of aminopeptidase, β-glucosidase and arylsulphatase and incorporation rates of (14)C-glucose and (14)C-acetate. Communities in unvegetated habitat were, in contrast, associated with both higher pH and proportion of sulphate reducing bacteria.
authors.affiliation: Centre for Environmental and Marine Studies & Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: D F R
authors.initials: DF
authors.lastname: Cleary
authors.forename: V
authors.initials: V
authors.lastname: Oliveira
authors.forename: N C M
authors.initials: NC
authors.lastname: Gomes
authors.forename: A
authors.initials: A
authors.lastname: Pereira
authors.forename: I
authors.initials: I
authors.lastname: Henriques
authors.forename: B
authors.initials: B
authors.lastname: Marques
authors.forename: A
authors.initials: A
authors.lastname: Almeida
authors.forename: A
authors.initials: A
authors.lastname: Cunha
authors.forename: A
authors.initials: A
authors.lastname: Correia
authors.forename: A I
authors.initials: AI
authors.lastname: Lillebø
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics; D018407:Bacterial Physiological Phenomena / Q000187:drug effects*; D029785:Cyperaceae / Q000502:physiology*; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D019684:Magnoliopsida / Q000502:physiology*; D008628:Mercury / Q000032:analysis / Q000633:toxicity*; D018521:Plant Physiological Phenomena; D012336:RNA, Ribosomal, 16S; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D053833:Wetlands
chemical_list: D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; D008628:Mercury