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Ekstam, Börje
Publications (10 of 16) Show all publications
Lindh, M. V., Sjöstedt, J., Ekstam, B., Casini, M., Lundin, D., Hugerth, L., . . . Pinhassi, J. (2017). Metapopulation theory identifies biogeographical patterns among core and satellite marine bacteria scaling from tens to thousands of kilometers. Environmental Microbiology, 19(3), 1222-1236
Open this publication in new window or tab >>Metapopulation theory identifies biogeographical patterns among core and satellite marine bacteria scaling from tens to thousands of kilometers
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2017 (English)In: Environmental Microbiology, ISSN 1462-2912, E-ISSN 1462-2920, Vol. 19, no 3, p. 1222-1236Article in journal (Refereed) Published
Abstract [en]

Metapopulation theory developed in terrestrial ecology provides applicable frameworks for interpreting the role of local and regional processes in shaping species distribution patterns. Yet, empirical testing of metapopulation models on microbial communities is essentially lacking. We determined regional bacterioplankton dynamics from monthly transect sampling in the Baltic Sea Proper using 16S rRNA gene sequencing. A strong positive trend was found between local relative abundance and occupancy of populations. Notably, the occupancy-frequency distributions were significantly bimodal with a satellite mode of rare endemic populations and a core mode of abundant cosmopolitan populations (e.g. Synechococcus, SAR11 and SAR86 clade members). Temporal changes in population distributions supported several theoretical frameworks. Still, bimodality was found among bacterioplankton communities across the entire Baltic Sea, and was also frequent in globally distributed datasets. Datasets spanning waters with widely different physicochemical characteristics or environmental gradients typically lacked significant bimodal patterns. When such datasets were divided into subsets with coherent environmental conditions, bimodal patterns emerged, highlighting the importance of positive feedbacks between local abundance and occupancy within specific biomes. Thus, metapopulation theory applied to microbial biogeography can provide novel insights into the mechanisms governing shifts in biodiversity resulting from natural or anthropogenically induced changes in the environment.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2017
National Category
Ecology Microbiology
Research subject
Ecology, Microbiology; Natural Science, Ecology
Identifiers
urn:nbn:se:lnu:diva-61540 (URN)10.1111/1462-2920.13650 (DOI)000397525100031 ()28028880 (PubMedID)
Projects
EcoChange
Available from: 2017-03-21 Created: 2017-03-21 Last updated: 2018-04-24Bibliographically approved
Svensson, H., Ekstam, B., Marques, M. & Hogland, W. (2015). Removal of organic pollutants from oak leachate in pilot scale wetland systems: How efficient are aeration and vegetation treatments?. Water Research, 84, 120-126
Open this publication in new window or tab >>Removal of organic pollutants from oak leachate in pilot scale wetland systems: How efficient are aeration and vegetation treatments?
2015 (English)In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 84, p. 120-126Article in journal (Refereed) Published
Abstract [en]

This study investigated the effects of aeration and/or vegetation in experimental constructed wetlands (CWs) as mesocosms on the removal of pollutants in oak wood leachate. Twelve outdoor wetland mesocosms, with randomized replicated treatment combinations of vegetation (Phragmites australis) and aeration was monitored during the second and third year after construction. The investigation included control tanks with no aeration and no vegetation. The parameters monitored were polyphenols (PPs), chemical oxygen demand (COD) and water colour. The reduction of COD after 28 days was approx. 50% and more than 50% of PPs, whereas only 40% of the water colour was removed. Aeration increased the effect of both COD and PP removal. The vegetation treatment had a small but significant effect on removal of COD. The vegetation + aeration treatment, as well as aeration alone, increased the removal efficiency of COD from 9.5 g m(-3) d(-1) in the control to 11 g m(-3) d(-1). The results suggest that CWs can be used to treat stormwater contaminated by oak wood leachate. Further, it is suggested that the main processes for removal of pollutants in the leachate occur in the open-water habitat and that the hydraulic retention time is more important for removal than aeration and vegetation related processes.

Keywords
Constructed wetland, Wood leachate, COD, Aeration
National Category
Environmental Sciences
Research subject
Natural Science, Environmental Science
Identifiers
urn:nbn:se:lnu:diva-46889 (URN)10.1016/j.watres.2015.07.017 (DOI)000362147400014 ()26218465 (PubMedID)2-s2.0-84937874543 (Scopus ID)
Available from: 2015-10-26 Created: 2015-10-26 Last updated: 2017-12-01Bibliographically approved
Ekstam, B. (2013). Åtgärdsprogram för skaftslamkrypa Elatine hexandra [Lapierre] DC.. Göteborg: Havs- och vattenmyndigheten
Open this publication in new window or tab >>Åtgärdsprogram för skaftslamkrypa Elatine hexandra [Lapierre] DC.
2013 (Swedish)Report (Refereed)
Abstract [en]

This action plan provides guidelines for preservation of the endangered plant Elatine hexandra (Six-stamened Waterwort) in Sweden. The action plan is a proposal, not a legally binding document.

Elatine hexandra is a small, aquatic or amphibious, vascular herb in the family Elatinaceae. In Sweden, it usually appears as a summer annual on the very edge of freshwater lakes or streams. Some populations have over-wintering individuals that occur at depths well below the ice-cover. Typically, the habitat is a moderately wave exposed littoral with inorganic, silty-sandy substrate, covered with a thin layer of mud. The lake habitats have clear water, a near neutral pH and may rep-resent one of the two lake types that are included in the habitat directive, i.e. “Oligotrophic waters containing very few minerals of sandy plains” and “Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoëto-Nanojuncetea”.

The species has been found in approx. 55 Swedish lakes or running waters since 1980. With a few exceptions, the occurrences are restricted to river basins of southwest Sweden with outlets in Skagerrak and Kattegat (County Administration Boards of Värmland, Västra Götaland, Jönköping, Halland and Kronoberg). In the Swedish red list Elatine hexandra is classified as Endangered (EN).

The main threats include deteriorating water quality. Eutrophication, acidification and brownification (increase in water color and dissolved organic matter) have adverse effects on growth and reproduction of the species. Other threats include exploitation of shorelines and water level regulations. The action plan proposes measures against deteriorating water quality in lakes with known occurrences of Elatine hexandra. Further, it points out the need for revision and ecological considerations of present water level regulations. Other suggestions aims to increase the conservation awareness among land owners, nature resource managers and municipality planners. These suggestions include production and spread of an information folder and implementation of conservation related information in the database WISS (Water Information System Sweden). WISS is an open information tool used in the planning cycle of river basin management. Finally, the action plan proposes additional investigations of the distribution in lakes and of the presence in seed-banks, as well as field studies on how growth and reproduction is affected by water regulations. With help of these results, lakes suitable for restoration measures can be selected. The action plan is valid for the period 2013-2018 and the costs are estimated to approx. 1 430 000 SEK

Place, publisher, year, edition, pages
Göteborg: Havs- och vattenmyndigheten, 2013. p. 45
Series
Havs- och vattenmyndighetens rapport ; 2013:8
National Category
Ecology
Research subject
Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-30391 (URN)978-91-87025-33-4 (ISBN)
Available from: 2013-11-13 Created: 2013-11-13 Last updated: 2013-11-15Bibliographically approved
Ekstam, B., Johansson, B., Dinnétz, P. & Ellström, P. (2011). Predicting risk habitats for the transmission of the small liver fluke, Dicrocoelium dendriticum to grazing ruminants.. Geospatial Health, 6(1), 125-131
Open this publication in new window or tab >>Predicting risk habitats for the transmission of the small liver fluke, Dicrocoelium dendriticum to grazing ruminants.
2011 (English)In: Geospatial Health, ISSN 1827-1987, Vol. 6, no 1, p. 125-131Article in journal (Refereed) Published
Abstract [en]

A multiple regression model was used to analyse if the structure of vegetation and soil patches in grazed units (pastures) can be used as explanatory variables to predict the prevalence of Dicrocoelium dendriticum, a common parasite of cattle and sheep, in grazing cattle stocks on the Baltic island of Öland in southern Sweden.

The scale dependency was evaluated by comparing three levels of spatial resolution of patches. Prevalence data were obtained from slaughtered animals.

Our models predict that the prevalence of D. dendriticum increases in grazed areas with woody vegetation, whereas moist and wet areas decrease parasite prevalence. The predictive power of the statistical models increased with increasing level of patch resolution. Approximately 42% of the variation in parasite prevalence (angular transformation) was explained by the areal proportion of vegetation types (4th-root-transformed).

Based on the results obtained, we believe that our model strategy provides a rational and systematic tool to identify habitats that carry risk for D. dendriticum infection of ruminants, and that it can be applied to other parasites with similar life cycles such as Fasciola hepatica.

Place, publisher, year, edition, pages
Naples, Italy: Global Network for Geospatial Health, 2011
Keywords
Öland, liten leverflundra, vegetationstyper, parasitöverföring, riskhabitat
National Category
Natural Sciences Ecology
Research subject
Ecology, Aquatic Ecology; Ecology, Zoonotic Ecology
Identifiers
urn:nbn:se:lnu:diva-16032 (URN)
Available from: 2011-12-12 Created: 2011-12-12 Last updated: 2018-05-21Bibliographically approved
Ekstam, B. (2007). Reed bed biodiversity. In: Ikonen, I. & Hagelberg, E. (Ed.), Read Up on Reed (pp. 54-60). Turku, Finland: SW Finland Reg. Environm. Centre
Open this publication in new window or tab >>Reed bed biodiversity
2007 (English)In: Read Up on Reed / [ed] Ikonen, I. & Hagelberg, E., Turku, Finland: SW Finland Reg. Environm. Centre , 2007, p. 54-60Chapter in book (Other academic)
Place, publisher, year, edition, pages
Turku, Finland: SW Finland Reg. Environm. Centre, 2007
National Category
Natural Sciences
Research subject
Natural Science, Evolutionary Biology; Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-4080 (URN)978-952-11-2780-9 (ISBN)
Available from: 2010-04-27 Created: 2010-04-27 Last updated: 2011-10-14Bibliographically approved
Ekstam, B., Karlsson, T. & Wäglind, J. (2004). Strandmorfometri, vattenståndsförhållanden och vegetation vid Nerängarna och Lillåns utlopp i Emån, NV Emsfors. Projektrapport till Länsstyrelsen i Kalmar: Högskolan i Kalmar
Open this publication in new window or tab >>Strandmorfometri, vattenståndsförhållanden och vegetation vid Nerängarna och Lillåns utlopp i Emån, NV Emsfors
2004 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Projektrapport till Länsstyrelsen i Kalmar: Högskolan i Kalmar, 2004. p. 24
Research subject
Natural Science, Evolutionary Biology; Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-3542 (URN)
Note
Nummer: Available from: 2010-04-26 Created: 2010-04-26 Last updated: 2011-09-29Bibliographically approved
Ekstam, B. (2004). Växtval och etableringsmetoder. Högskolan i Kalmar
Open this publication in new window or tab >>Växtval och etableringsmetoder
2004 (Swedish)Report (Other academic)
Place, publisher, year, edition, pages
Högskolan i Kalmar, 2004. p. 11
Series
Projekt Säby Våtmark. Delprojekt Våtmark - Process
Research subject
Natural Science, Evolutionary Biology; Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-3543 (URN)
Note
Nummer: Available from: 2010-04-26 Created: 2010-04-26 Last updated: 2011-09-29Bibliographically approved
Tonderski, K., Svensson, J., Ekstam, B., Eriksson, P., Fleischer, S., Herrmann, J., . . . Weisner, S. (2003). Våtmarker - närsaltsfällor och/eller myllrande mångfald?. Vatten - tidskrift för vattenvård, 59(4), 259-270
Open this publication in new window or tab >>Våtmarker - närsaltsfällor och/eller myllrande mångfald?
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2003 (Swedish)In: Vatten - tidskrift för vattenvård, ISSN 0042-2886, Vol. 59, no 4, p. 259-270Article in journal (Other academic) Published
Research subject
Natural Science, Evolutionary Biology; Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2730 (URN)
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2011-09-29Bibliographically approved
Ekstam, B., Ekelund, S., Aleljung, S.-O. & Hevelius, C. (2003). Våtmarker i Borgholms kommun. Borgholms kommun
Open this publication in new window or tab >>Våtmarker i Borgholms kommun
2003 (Swedish)In: Borgholms kommunArticle in journal (Other (popular science, discussion, etc.)) Published
Research subject
Natural Science, Evolutionary Biology; Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-2781 (URN)
Available from: 2010-04-23 Created: 2010-04-23 Last updated: 2011-09-29Bibliographically approved
Ekstam, B. (2001). Vattnet i landskapet. In: Forslund, M. (Ed.), Natur oh kultur på Öland. Kalmar: Länsstyrelsen i Kalmar
Open this publication in new window or tab >>Vattnet i landskapet
2001 (Swedish)In: Natur oh kultur på Öland / [ed] Forslund, M., Kalmar: Länsstyrelsen i Kalmar , 2001Chapter in book (Other academic)
Place, publisher, year, edition, pages
Kalmar: Länsstyrelsen i Kalmar, 2001
Research subject
Natural Science, Evolutionary Biology; Natural Science, Aquatic Ecology
Identifiers
urn:nbn:se:lnu:diva-4082 (URN)91-973802-4-5 (ISBN)
Available from: 2010-04-27 Created: 2010-04-27 Last updated: 2011-09-22Bibliographically approved
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