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Brunberg, Anna-Kristina
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Publikasjoner (10 av 16) Visa alla publikasjoner
Vrede, T., Ballantyne, A. P., Mille-Lindblom, C., Algesten, G., Gudasz, C., Lindahl, S. & Brunberg, A.-K. (2009). Effects of N:P loading ratios on phytoplankton community composition, primary production, and N fixation in a eutrophic lake. Freshwater Biology, 54(2), 331-344
Åpne denne publikasjonen i ny fane eller vindu >>Effects of N:P loading ratios on phytoplankton community composition, primary production, and N fixation in a eutrophic lake
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2009 (engelsk)Inngår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 54, nr 2, s. 331-344Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

1. The aim of this study was to assess the effects of different nitrogen (N) to  phosphorus (P) loading ratios on phytoplankton community composition and primary production in a naturally eutrophic lake. Furthermore, the sources of N fuelling primary production were estimated using 15N stable isotope tracers.

2. A mesocosm experiment was performed with the same amount of P added to all mesocosms (similar to internal loading rates) but with a range of N additions (0–86 μm N), resulting in a gradient of N : P supply ratios.

3. Low N : P supply ratios resulted in a significant shift in the phytoplankton assemblage to a community dominated by N-fixing cyanobacteria and a supply of atmospheric N2 estimated to be up to 60% of total supply.

4. The N : P loading ratio had no significant effect on primary production, total nitrogen (TN) concentration or particulate N concentration.

5. Our results imply that a reduced N : P ratio of the nutrient load does not necessarily result in a lower TN concentration and downstream N export due to compensation by N-fixing cyanobacteria.

 

 

Emneord
15N stable isotopes, eutrophication, nitrogen, phosphorus, stoichiometry
HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-111716 (URN)10.1111/j.1365-2427.2008.02118.x (DOI)000262470300009 ()
Tilgjengelig fra: 2009-12-21 Laget: 2009-12-21 Sist oppdatert: 2022-01-28bibliografisk kontrollert
Sobek, S., Söderbäck, B., Karlsson, S., Andersson, E. & Brunberg, A.-K. (2006). A carbon budget of a small humic lake: An example of the importance of lakes for organic matter cycling in boreal catchments. Ambio, 35(8), 469-475
Åpne denne publikasjonen i ny fane eller vindu >>A carbon budget of a small humic lake: An example of the importance of lakes for organic matter cycling in boreal catchments
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2006 (engelsk)Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 35, nr 8, s. 469-475Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Lakes play an important role in the cycling of organic matter in the boreal landscape, due to the frequently high extent of bacterial respiration and the efficient burial of organic carbon in sediments. Based on a mass balance approach, we calculated a carbon budget for a small humic Swedish lake in the vicinity of a potential final repository for radioactive waste in Sweden, in order to assess its potential impact on the environmental fate of radionuclides associated with organic matter. We found that the lake is a net heterotrophic ecosystem, subsidized by organic carbon inputs from the catchment and from emergent macrophyte production. The largest sink of organic carbon is respiration by aquatic bacteria and subsequent emission of carbon dioxide to the atmosphere. Although the annual burial of organic carbon in the sediment is a comparatively small sink, it results in the build-up of the largest carbon pool in the lake. Hence, lakes may simultaneously disperse and accumulate organic-associated radionuclides leaking from a final repository.

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Identifikatorer
urn:nbn:se:uu:diva-23080 (URN)10.1579/0044-7447(2006)35[469:ACBOAS]2.0.CO;2 (DOI)000243606600006 ()17334054 (PubMedID)
Tilgjengelig fra: 2008-01-28 Laget: 2008-01-28 Sist oppdatert: 2018-06-05
Andersson, E. & Brunberg, A.-K. (2006). Inorganic nutrient acquisition in a shallow clearwater lake: dominance of benthic microbiota. Aquatic Sciences, 68(2), 172-180
Åpne denne publikasjonen i ny fane eller vindu >>Inorganic nutrient acquisition in a shallow clearwater lake: dominance of benthic microbiota
2006 (engelsk)Inngår i: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 68, nr 2, s. 172-180Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

This mesocosm study from the oligotrophic Lake Eckarfjärden in Sweden shows, in contrast to many previous studies, that benthic microbiota dominated production following elevated nutrient concentrations in the water. Increased nutrient concentrations favoured microphytobenthos, whereas phytoplankton biomass remained roughly the same. Microphytobenthos biomass and production were clearly stimulated by nitrogen addition, while phytoplankton showed signs of phosphorus limitation. There were tight interactions between pelagic and benthic habitats and between organisms, and pelagic as well as benthic heterotrophic bacteria were disfavoured when microphytobenthos had access to nitrogen.

We conclude that increased nutrient concentrations in the water column may trigger immediate responses in both habitats, altering the tight interactions between microbiota, but not necessarily resulting in a shift towards pelagic production.

HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-93056 (URN)10.1007/s00027-006-0805-x (DOI)
Tilgjengelig fra: 2005-05-11 Laget: 2005-05-11 Sist oppdatert: 2018-06-05bibliografisk kontrollert
Andersson, E. & Brunberg, A.-K. (2006). Net autotrophy in an oligotrophic lake rich in dissolved organic carbon and with high benthic primary production. Aquatic Microbial Ecology, 43(1), 1-10
Åpne denne publikasjonen i ny fane eller vindu >>Net autotrophy in an oligotrophic lake rich in dissolved organic carbon and with high benthic primary production
2006 (engelsk)Inngår i: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, Vol. 43, nr 1, s. 1-10Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Biomass and production of microbiota—primary producers as well as heterotrophic bacteria—were studied both in the pelagial and in the benthic habitat over 2 yr in the shallow oligotrophic Lake Eckarfjärden, Sweden. Both biomass and production of microbiota were concentrated in the benthic habitat. Despite a high dissolved organic carbon (DOC) concentration of about 25 mg C l–1 in the water, the total bacterial production was lower than the total primary production. Moreover, measurements of DOC concentrations in the in- and outflow, and CO2-saturation measurements, indicate that the system is net autotrophic. Generally, low-productive systems (<100 µg C l–1 d–1) tend to be net heterotrophic. In contrast, we found a low-productive (55 µg C l–1 d–1) but net autotrophic system, the conditions of which were largely influenced by benthic production. Many lakes in the world are shallow and may provide substantial benthic areas suitable for primary production. Hence, it is important to include this habitat when evaluating whether lakes are autotrophic or heterotrophic systems.

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Identifikatorer
urn:nbn:se:uu:diva-93055 (URN)10.3354/ame043001 (DOI)
Tilgjengelig fra: 2005-05-11 Laget: 2005-05-11 Sist oppdatert: 2018-06-05bibliografisk kontrollert
Brydsten, L., Carlsson, T., Brunberg, A.-K. & Blomqvist, P. (2004). A method for determination of morphometry, sediment distribution, and habitat diversity of lake basins and its application to three lakes in Uppland.. Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden.
Åpne denne publikasjonen i ny fane eller vindu >>A method for determination of morphometry, sediment distribution, and habitat diversity of lake basins and its application to three lakes in Uppland.
2004 (engelsk)Rapport (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden., 2004
Identifikatorer
urn:nbn:se:uu:diva-79182 (URN)
Tilgjengelig fra: 2006-04-05 Laget: 2006-04-05 Sist oppdatert: 2018-06-05
Brunberg, A.-K., Carlsson, T., Brydsten, L. & Strömgren, M. (2004). Forsmark site investigation. Identification of catchments, lake-related drainage parameters and lake habitats.. Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden.
Åpne denne publikasjonen i ny fane eller vindu >>Forsmark site investigation. Identification of catchments, lake-related drainage parameters and lake habitats.
2004 (engelsk)Rapport (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden., 2004
Identifikatorer
urn:nbn:se:uu:diva-79183 (URN)
Tilgjengelig fra: 2006-04-05 Laget: 2006-04-05 Sist oppdatert: 2018-06-05
Brunberg, A.-K., Carlsson, T., Brydsten, L. & Strömgren, M. (2004). Oskarshamn site investigation. Identification of catchments, lake-related drainage parameters and lake habitats.. Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden.
Åpne denne publikasjonen i ny fane eller vindu >>Oskarshamn site investigation. Identification of catchments, lake-related drainage parameters and lake habitats.
2004 (engelsk)Rapport (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden., 2004
Identifikatorer
urn:nbn:se:uu:diva-79186 (URN)
Tilgjengelig fra: 2006-04-05 Laget: 2006-04-05 Sist oppdatert: 2018-06-05
Karlsson-Elfgren, I. & Brunberg, A.-K. (2004). The Importance of Shallow Sediments in the Recruitment of Anabaena and Aphanizomenon (Cyanophyceae). Journal of Phycology, 40(5), 831-836
Åpne denne publikasjonen i ny fane eller vindu >>The Importance of Shallow Sediments in the Recruitment of Anabaena and Aphanizomenon (Cyanophyceae)
2004 (engelsk)Inngår i: Journal of Phycology, ISSN 0022-3646, E-ISSN 1529-8817, Vol. 40, nr 5, s. 831-836Artikkel i tidsskrift (Fagfellevurdert) Published
Abstract [en]

Recruitment of Anabaena and Aphanizomenon from the sediments to the water column was investigated in shallow (1-2 m) and deep (6-7 m) areas of Lake Limmaren, central Sweden. Recruitment traps attached to the bottom were sampled weekly throughout the summer season (June through September). A comparison between the two sites shows that the largest part of the recruited cells originated from the shallow site, although recruitment occurred at all depths in the lake. There were also differences between the species, regarding the site as well as the timing of the recruitment. The contribution of the inoculum to the pelagic population was calculated to vary between 0.003% and 0.05% for the different species. From these results we conclude that shallow sediments are more important than deep ones for the recruitment and that the inoculum in Lake Limmaren is small but may still be an important factor in the population dynamics.

HSV kategori
Identifikatorer
urn:nbn:se:uu:diva-90428 (URN)10.1111/j.1529-8817.2004.04070.x (DOI)
Tilgjengelig fra: 2003-05-14 Laget: 2003-05-14 Sist oppdatert: 2018-06-05bibliografisk kontrollert
Brunberg, A.-K. & Blomqvist, P. (2003). Ontogeny of lake ecosystems in the Forsmark area - chemical analysis of deep sediment cores. Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden.
Åpne denne publikasjonen i ny fane eller vindu >>Ontogeny of lake ecosystems in the Forsmark area - chemical analysis of deep sediment cores
2003 (engelsk)Rapport (Annet vitenskapelig)
sted, utgiver, år, opplag, sider
Swedish Nuclear Fuel and Waste Management Co., Stockholm, Sweden., 2003
Identifikatorer
urn:nbn:se:uu:diva-47535 (URN)
Tilgjengelig fra: 2006-04-05 Laget: 2006-04-05 Sist oppdatert: 2018-06-05
Brunberg, A.-K. & Blomqvist, P. (2003). Recruitment of Microcystis (Cyanophyceae) from lake sediments: the importance of littoral inocula. J. Phycol., 39, 58-63.
Åpne denne publikasjonen i ny fane eller vindu >>Recruitment of Microcystis (Cyanophyceae) from lake sediments: the importance of littoral inocula
2003 (engelsk)Inngår i: J. Phycol., Vol. 39, s. 58-63.Artikkel i tidsskrift (Fagfellevurdert) Published
Identifikatorer
urn:nbn:se:uu:diva-47534 (URN)
Tilgjengelig fra: 2006-04-05 Laget: 2006-04-05 Sist oppdatert: 2018-06-05
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