uu.seUppsala University Publications
Change search
Link to record
Permanent link

Direct link
BETA
Publications (6 of 6) Show all publications
Attermeyer, K., Grossart, H.-P., Flury, S. & Premke, K. (2017). Bacterial processes and biogeochemical changes in the water body of kettle holes: mainly driven by autochthonous organic matter?. Aquatic Sciences, 79(3), 675-687
Open this publication in new window or tab >>Bacterial processes and biogeochemical changes in the water body of kettle holes: mainly driven by autochthonous organic matter?
2017 (English)In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 79, no 3, p. 675-687Article in journal (Refereed) Published
Abstract [en]

Kettle holes are small inland waters formed from glacially-created depressions often situated in agricultural landscapes. Due to their high perimeter-to-area ratio facilitating a high aquatic-terrestrial coupling, kettle holes can accumulate high concentrations of organic carbon and nutrients, fueling microbial activities and turnover rates. Thus, they represent hotspots of carbon turnover in the landscape, but their bacterial activities and controlling factors have not been well investigated. Therefore, we aimed to assess the relative importance of various environmental factors on bacterial and biogeochemical processes in the water column of kettle holes and to disentangle their variations. In the water body of ten kettle holes in north-eastern Germany, we measured several physico-chemical and biological parameters such as carbon quantity and quality, as well as bacterial protein production (BP) and community respiration (CR) in spring, early summer and autumn 2014. Particulate organic matter served as an indicator of autochthonous production and represented an important parameter to explain variations in BP and CR. This notion is supported by qualitative absorbance indices of dissolved molecules in water samples and C:N ratios of the sediments, which demonstrate high fractions of autochthonous organic matter (OM) in the studied kettle holes. In contrast, dissolved chemical parameters were less important for bacterial activities although they revealed strong differences throughout the growing season. Pelagic bacterial activities and dynamics might thus be regulated by autochthonous OM in kettle holes implying a control of important biogeochemical processes by internal primary production rather than facilitated exchange with the terrestrial surrounding due to a high perimeter-to-area ratio.

Keywords
Bacterial production, Carbon turnover, Growth efficiency, Ponds, Respiration, DOC quality, LC-OCD
National Category
Ecology Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:uu:diva-323614 (URN)10.1007/s00027-017-0528-1 (DOI)000405798900019 ()
Available from: 2017-06-08 Created: 2017-06-08 Last updated: 2018-01-13Bibliographically approved
Lischke, B., Mehner, T., Hilt, S., Attermeyer, K., Brauns, M., Brothers, S., . . . Gaedke, U. (2017). Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes. Freshwater Biology, 62(10), 1693-1706
Open this publication in new window or tab >>Benthic carbon is inefficiently transferred in the food webs of two eutrophic shallow lakes
Show others...
2017 (English)In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 62, no 10, p. 1693-1706Article in journal (Refereed) Published
Abstract [en]

1. The sum of benthic autotrophic and bacterial production often exceeds the sum of pelagic autotrophic and bacterial production, and hence may contribute sub- stantially to whole-lake carbon fluxes, especially in shallow lakes. Furthermore, both benthic and pelagic autotrophic and bacterial production are highly edible and of sufficient nutritional quality for animal consumers. We thus hypothesised that pelagic and benthic transfer efficiencies (ratios of production at adjacent trophic levels) in shallow lakes should be similar. 2. We performed whole ecosystem studies in two shallow lakes (3.5 ha, mean depth 2 m), one with and one without submerged macrophytes, and quantified pelagic and benthic biomass, production and transfer efficiencies for bacteria, phytoplank- ton, epipelon, epiphyton, macrophytes, zooplankton, macrozoobenthos and fish. We expected higher transfer efficiencies in the lake with macrophytes, because these provide shelter and food for macrozoobenthos and may thus enable a more efficient conversion of basal production to consumer production. 3. In both lakes, the majority of the whole-lake autotrophic and bacterial produc- tion was provided by benthic organisms, but whole-lake primary consumer pro- duction mostly relied on pelagic autotrophic and bacterial production. Consequently, transfer efficiency of benthic autotrophic and bacterial production to macrozoobenthos production was an order of magnitude lower than the transfer efficiency of pelagic autotrophic and bacterial production to rotifer and crustacean production. Between-lake differences in transfer efficiencies were minor. 4. We discuss several aspects potentially causing the unexpectedly low benthic transfer efficiencies, such as the food quality of producers, pelagic–benthic links, oxygen concentrations in the deeper lake areas and additional unaccounted con- sumer production by pelagic and benthic protozoa and meiobenthos at interme- diate or top trophic levels. None of these processes convincingly explain the large differences between benthic and pelagic transfer efficiencies. 5. Our data indicate that shallow eutrophic lakes, even with a major share of auto- trophic and bacterial production in the benthic zone, can function as pelagic sys- tems with respect to primary consumer production. We suggest that the benthic autotrophic production was mostly transferred to benthic bacterial production, which remained in the sediments, potentially cycling internally in a similar way to what has previously been described for the microbial loop in pelagic habitats. Understanding the energetics of whole-lake food webs, including the fate of the substantial benthic bacterial production, which is either mineralised at the sedi- ment surface or permanently buried, has important implications for regional and global carbon cycling

Keywords
bacterial production, benthic food chain, pelagic food chain, quantitative food webs, trophic transfer efficiency
National Category
Biological Sciences
Identifiers
urn:nbn:se:uu:diva-334883 (URN)10.1111/fwb.12979 (DOI)000410094000003 ()
Available from: 2017-11-29 Created: 2017-11-29 Last updated: 2018-05-17Bibliographically approved
Wurzbacher, C., Attermeyer, K., Kettner, M. T., Flintrop, C., Warthmann, N., Hilt, S., . . . Monaghan, M. T. (2017). DNA metabarcoding of unfractionated water samples relates phyto-, zoo- and bacterioplankton dynamics and reveals a single-taxon bacterial bloom. Environmental Microbiology Reports, 9(4), 383-388
Open this publication in new window or tab >>DNA metabarcoding of unfractionated water samples relates phyto-, zoo- and bacterioplankton dynamics and reveals a single-taxon bacterial bloom
Show others...
2017 (English)In: Environmental Microbiology Reports, ISSN 1758-2229, E-ISSN 1758-2229, Vol. 9, no 4, p. 383-388Article in journal (Refereed) Published
Abstract [en]

Most studies of aquatic plankton focus on either macroscopic or microbial communities, and on either eukaryotes or prokaryotes. This separation is primarily for methodological reasons, but can overlook potential interactions among groups. We tested whether DNA metabarcoding of unfractionated water samples with universal primers could be used to qualitatively and quantitatively study the temporal dynamics of the total plankton community in a shallow temperate lake. We found significant changes in the relative proportions of normalized sequence reads of eukaryotic and prokaryotic plankton communities over a three-month period in spring. Patterns followed the same trend as plankton estimates measured using traditional microscopic methods. We characterized the bloom of a conditionally rare bacterial taxon belonging to Arcicella, which rapidly came to dominate the whole lake ecosystem and would have remained unnoticed without metabarcoding. Our data demonstrate the potential of universal DNA metabarcoding applied to unfractionated samples for providing a more holistic view of plankton communities.

National Category
Microbiology Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:uu:diva-323620 (URN)10.1111/1758-2229.12540 (DOI)000405931900005 ()28429584 (PubMedID)
Available from: 2017-06-08 Created: 2017-06-08 Last updated: 2018-01-13Bibliographically approved
Wurzbacher, C., Fuchs, A., Attermeyer, K., Frindte, K., Grossart, H.-P., Hupfer, M., . . . Monaghan, M. T. (2017). Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment. Microbiome, 5, Article ID 41.
Open this publication in new window or tab >>Shifts among Eukaryota, Bacteria, and Archaea define the vertical organization of a lake sediment
Show others...
2017 (English)In: Microbiome, ISSN 0026-2633, E-ISSN 2049-2618, Vol. 5, article id 41Article in journal (Refereed) Published
Abstract [en]

Background: Lake sediments harbor diverse microbial communities that cycle carbon and nutrients while being constantly colonized and potentially buried by organic matter sinking from the water column. The interaction of activity and burial remained largely unexplored in aquatic sediments. We aimed to relate taxonomic composition to sediment biogeochemical parameters, test whether community turnover with depth resulted from taxonomic replacement or from richness effects, and to provide a basic model for the vertical community structure in sediments.

Methods: We analyzed four replicate sediment cores taken from 30-m depth in oligo-mesotrophic Lake Stechlin in northern Germany. Each 30-cm core spanned ca. 170 years of sediment accumulation according to 137Cs dating and was sectioned into layers 1–4 cm thick. We examined a full suite of biogeochemical parameters and used DNA metabarcoding to examine community composition of microbial Archaea, Bacteria, and Eukaryota.

Results: Community β-diversity indicated nearly complete turnover within the uppermost 30 cm. We observed a pronounced shift from Eukaryota- and Bacteria-dominated upper layers (<5 cm) to Bacteria-dominated intermediate layers (5–14 cm) and to deep layers (>14 cm) dominated by enigmatic Archaea that typically occur in deep-sea sediments. Taxonomic replacement was the prevalent mechanism in structuring the community composition and was linked to parameters indicative of microbial activity (e.g., CO2 and CH4 concentration, bacterial protein production). Richness loss played a lesser role but was linked to conservative parameters (e.g., C, N, P) indicative of past conditions.

Conclusions: By including all three domains, we were able to directly link the exponential decay of eukaryotes with the active sediment microbial community. The dominance of Archaea in deeper layers confirms earlier findings from marine systems and establishes freshwater sediments as a potential low-energy environment, similar to deep sea sediments. We propose a general model of sediment structure and function based on microbial characteristics and burial processes. An upper “replacement horizon” is dominated by rapid taxonomic turnover with depth, high microbial activity, and biotic interactions. A lower “depauperate horizon” is characterized by low taxonomic richness, more stable “low-energy” conditions, and a dominance of enigmatic Archaea.

Keywords
Archaea, Eukaryota, Bacteria, Community, Freshwater, Lake, DNA metabarcoding, Beta-diversity, Sediment, Turnover
National Category
Microbiology Oceanography, Hydrology and Water Resources
Identifiers
urn:nbn:se:uu:diva-323607 (URN)10.1186/s40168-017-0255-9 (DOI)000398528500001 ()28388930 (PubMedID)
Available from: 2017-06-08 Created: 2017-06-08 Last updated: 2018-01-13Bibliographically approved
Attermeyer, K., Flury, S., Jayakumar, R., Fiener, P., Steger, K., Arya, V., . . . Premke, K. (2016). Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake. Scientific Reports, 6, Article ID 20424.
Open this publication in new window or tab >>Invasive floating macrophytes reduce greenhouse gas emissions from a small tropical lake
Show others...
2016 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 20424Article in journal (Refereed) Published
Abstract [en]

Floating macrophytes, including water hyacinth (Eichhornia crassipes), are dominant invasive organisms in tropical aquatic systems, and they may play an important role in modifying the gas exchange between water and the atmosphere. However, these systems are underrepresented in global datasets of greenhouse gas (GHG) emissions. This study investigated the carbon (C) turnover and GHG emissions from a small (0.6 km(2)) water-harvesting lake in South India and analysed the effect of floating macrophytes on these emissions. We measured carbon dioxide (CO2) and methane (CH4) emissions with gas chambers in the field as well as water C mineralization rates and physicochemical variables in both the open water and in water within stands of water hyacinths. The CO2 and CH4 emissions from areas covered by water hyacinths were reduced by 57% compared with that of open water. However, the C mineralization rates were not significantly different in the water between the two areas. We conclude that the increased invasion of water hyacinths and other floating macrophytes has the potential to change GHG emissions, a process that might be relevant in regional C budgets.

National Category
Ecology
Identifiers
urn:nbn:se:uu:diva-279567 (URN)10.1038/srep20424 (DOI)000369385300002 ()26846590 (PubMedID)
Available from: 2016-03-02 Created: 2016-03-02 Last updated: 2017-11-30Bibliographically approved
Lischke, B., Weithoff, G., Wickham, S., Attermeyer, K., Grossart, H.-P., Scharnweber, K., . . . Gaedke, U. (2016). Large biomass of small feeders: Ciliates may dominate herbivory in eutrophic lakes. Journal of Plankton Research, 38(1), 2-15
Open this publication in new window or tab >>Large biomass of small feeders: Ciliates may dominate herbivory in eutrophic lakes
Show others...
2016 (English)In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 38, no 1, p. 2-15Article in journal (Refereed) Published
Abstract [en]

The importance of ciliates as herbivores and in biogeochemical cycles is increasingly recognized. An opportunity to observe the potential consequences of zooplankton dominated by ciliates arose when winter fish kills resulted in strong suppression of crustaceans by young planktivorous fish in two shallow lakes. On an annual average, ciliates made up 38-76% of the total zooplankton biomass in both lakes during two subsequent years. Consequently, ciliate biomass and their estimated grazing potential were extremely high compared with other lakes of various trophic states and depths. Grazing estimates based on abundance and size suggest that ciliates should have cleared the water column of small (<5 mu m) and intermediate (5-50 mu m) sized phytoplankton more than once a day. Especially, small feeders within the ciliates were important, likely exerting a strong top-down control on small phytoplankton. Particle-attached bacteria were presumably strongly suppressed by intermediate-sized ciliate feeders. In contrast to other lakes, large phytoplankton was proportionately very abundant. The phytoplankton community had a high evenness, which may be attributed to the feeding by numerous fast growing and selective ciliate species. Our study highlights ciliates as an important trophic link and adds to the growing awareness of the role of winter processes for plankton dynamics.

National Category
Natural Sciences Biological Sciences
Identifiers
urn:nbn:se:uu:diva-264654 (URN)10.1093/plankt/fbv102 (DOI)000371229900002 ()
Available from: 2015-10-15 Created: 2015-10-15 Last updated: 2017-12-01Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6503-9497

Search in DiVA

Show all publications