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  • 1. Abbott, Benjamin W.
    et al.
    Jones, Jeremy B.
    Schuur, Edward A. G.
    Chapin, F. Stuart, III
    Bowden, William B.
    Bret-Harte, M. Syndonia
    Epstein, Howard E.
    Flannigan, Michael D.
    Harms, Tamara K.
    Hollingsworth, Teresa N.
    Mack, Michelle C.
    McGuire, A. David
    Natali, Susan M.
    Rocha, Adrian V.
    Tank, Suzanne E.
    Turetsky, Merritt R.
    Vonk, Jorien E.
    Wickland, Kimberly P.
    Aiken, George R.
    Alexander, Heather D.
    Amon, Rainer M. W.
    Benscoter, Brian W.
    Bergeron, Yves
    Bishop, Kevin
    Blarquez, Olivier
    Bond-Lamberty, Ben
    Breen, Amy L.
    Buffam, Ishi
    Cai, Yihua
    Carcaillet, Christopher
    Carey, Sean K.
    Chen, Jing M.
    Chen, Han Y. H.
    Christensen, Torben R.
    Cooper, Lee W.
    Cornelissen, J. Hans C.
    de Groot, William J.
    DeLuca, Thomas H.
    Dorrepaal, Ellen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Fetcher, Ned
    Finlay, Jacques C.
    Forbes, Bruce C.
    French, Nancy H. F.
    Gauthier, Sylvie
    Girardin, Martin P.
    Goetz, Scott J.
    Goldammer, Johann G.
    Gough, Laura
    Grogan, Paul
    Guo, Laodong
    Higuera, Philip E.
    Hinzman, Larry
    Hu, Feng Sheng
    Hugelius, Gustaf
    Jafarov, Elchin E.
    Jandt, Randi
    Johnstone, Jill F.
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Kasischke, Eric S.
    Kattner, Gerhard
    Kelly, Ryan
    Keuper, Frida
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Kling, George W.
    Kortelainen, Pirkko
    Kouki, Jari
    Kuhry, Peter
    Laudon, Hjalmar
    Laurion, Isabelle
    Macdonald, Robie W.
    Mann, Paul J.
    Martikainen, Pertti J.
    McClelland, James W.
    Molau, Ulf
    Oberbauer, Steven F.
    Olefeldt, David
    Pare, David
    Parisien, Marc-Andre
    Payette, Serge
    Peng, Changhui
    Pokrovsky, Oleg S.
    Rastetter, Edward B.
    Raymond, Peter A.
    Raynolds, Martha K.
    Rein, Guillermo
    Reynolds, James F.
    Robards, Martin
    Rogers, Brendan M.
    Schaedel, Christina
    Schaefer, Kevin
    Schmidt, Inger K.
    Shvidenko, Anatoly
    Sky, Jasper
    Spencer, Robert G. M.
    Starr, Gregory
    Striegl, Robert G.
    Teisserenc, Roman
    Tranvik, Lars J.
    Virtanen, Tarmo
    Welker, Jeffrey M.
    Zimov, Sergei
    Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment2016Inngår i: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 11, nr 3, 034014Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%-85% of permafrost carbon release can still be avoided if human emissions are actively reduced.

  • 2. Abdoullaye, Doukary
    et al.
    Acevedo, I
    Adebayo, Abisola A
    Behrmann-Godel, Jasminca
    Benjamin, RC
    Bock, Dan G
    Born, Celine
    Brouat, Carine
    Caccone, Adalgisa
    Cao, Ling-Zhen
    Casadoamezua, P
    Cataneo, J
    Correa-Ramirez, MM
    Cristescu, Melania E
    Dobigny, Gauthier
    Egbosimba, Emmanuel E
    Etchberger, Lianna K
    Fan, Bin
    Fields, Peter D
    Forcioli, D
    Furla, P
    de Leon, FJ Garcia
    Garcia-Jimenez, R
    Gauthier, Philippe
    Gergs, Rene
    Gonzalez, Clementina
    Granjon, Laurent
    Gutierrez-Rodriguez, Carla
    Havill, Nathan P
    Helsen, P
    Hether, Tyler D
    Hoffman, Eric A
    Hu, Xiangyang
    Ingvarsson, Pär K
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ishizaki, S
    Ji, Heyi
    Ji, XS
    Jimenez, ML
    Kapil, R
    Karban, R
    Keller, Stephen R
    Kubota, S
    Li, Shuzhen
    Li, Wansha
    Lim, Douglas D
    Lin, Haoran
    Liu, Xiaochun
    Luo, Yayan
    Machordom, A
    Martin, Andrew P
    Matthysen, E
    Mazzella, Maxwell N
    McGeoch, Melodie A
    Meng, Zining
    Nishizawa, M
    O'Brien, Patricia
    Ohara, M
    Ornelas, Juan Francisco
    Ortu, MF
    Pedersen, Amy B
    Preston, L
    Ren, Qin
    Rothhaupt, Karl-Otto
    Sackett, Loren C
    Sang, Qing
    Sawyer, GM
    Shiojiri, K
    Taylor, Douglas R
    van Dongen, S
    van Vuuren, Bettine Jansen
    Vandewoestijne, S
    Wang, H
    Wang, JT
    Wang, Le
    Xu, Xiang-Li
    Yang, Guang
    Yang, Yongping
    Zeng, YQ
    Zhang, Qing-Wen
    Zhang, Yongping
    Zhao, Y
    Zhou, Yan
    Permanent genetic resources added to molecular ecology resources database 1 August 2009 - 30 September 20092010Inngår i: Molecular Ecology Resources, ISSN 1755-098X, E-ISSN 1755-0998, Vol. 10, nr 1, 232-236 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This article documents the addition of 238 microsatellite marker loci and 72 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Adelges tsugae, Artemisia tridentata, Astroides calycularis, Azorella selago, Botryllus schlosseri, Botrylloides violaceus, Cardiocrinum cordatum var. glehnii, Campylopterus curvipennis, Colocasia esculenta, Cynomys ludovicianus, Cynomys leucurus, Cynomys gunnisoni, Epinephelus coioides, Eunicella singularis, Gammarus pulex, Homoeosoma nebulella, Hyla squirella, Lateolabrax japonicus, Mastomys erythroleucus, Pararge aegeria, Pardosa sierra, Phoenicopterus ruber ruber and Silene latifolia. These loci were cross-tested on the following species: Adelges abietis, Adelges cooleyi, Adelges piceae, Pineus pini, Pineus strobi, Tubastrea micrantha, three other Tubastrea species, Botrylloides fuscus, Botrylloides simodensis, Campylopterus hemileucurus, Campylopterus rufus, Campylopterus largipennis, Campylopterus villaviscensio, Phaethornis longuemareus, Florisuga mellivora, Lampornis amethystinus, Amazilia cyanocephala, Archilochus colubris, Epinephelus lanceolatus, Epinephelus fuscoguttatus, Symbiodinium temperate-A clade, Gammarus fossarum, Gammarus roeselii, Dikerogammarus villosus and Limnomysis benedeni. This article also documents the addition of 72 sequencing primer pairs and 52 allele specific primers for Neophocaena phocaenoides.

  • 3. Abeli, Thomas
    et al.
    Orsenigo, Simone
    Guzzon, Filippo
    Fae, Matteo
    Balestrazzi, Alma
    Carlsson-Graner, Ulla
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Mueller, Jonas V.
    Mondoni, Andrea
    Geographical pattern in the response of the arctic-alpine Silene suecica (Cariophyllaceae) to the interaction between water availability and photoperiod2015Inngår i: Ecological research, ISSN 0912-3814, E-ISSN 1440-1703, Vol. 30, nr 2, 327-335 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We hypothesized a geographical pattern of the plant performance (seedling development, biomass production, relative water content and chlorophyll content) as a result of response to the interaction between photoperiod and water availability in populations of the arctic-alpine Silene suecica from different latitudes, thus experiencing different photoperiods during the growing season. Particularly, we expected a lower drought sensitivity in northern compared to southern populations as a consequence of harsher conditions experienced by the northern populations in terms of water availability. The experiment was carried out under common garden conditions, manipulating the water availability (wet and dry) and the photoperiod (21 and 16 h). We found an interaction between photoperiod and water availability on plant height, leaves, growth, biomass and total chlorophyll. However, the photoperiod neither counteracted nor intensified the effect of drought. Plants exposed to drought compensated for decreasing water availability by reducing their shoot growth. Changes in the chlorophyll content and chlorophyll a/b ratio were observed. Northern populations showed a higher basal growth performance and a greater response to the changed water regime (from wet to dry) than the southern populations. Southern populations showed a reduced ability to respond to drought, but their low basal performance may be advantageous under low water availability, avoiding water loss. In contrast, northern populations showed a stronger plastic response that limited the negative effects of reduced water availability. This study highlights the possibility that the plant response to environmental constraints (specifically water availability) may follow a geographical pattern.

  • 4.
    Abrahamsson, Matilda
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Metoder för utredning av inomhusmiljö: En studie inom hälsoskyddet med delsyfte att utföra dammätningar i skolor2012Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Methods for inspection of the indoor environment – a study within health protection where a part of the aim is to perform measurements of dust in schools

    In Sweden the communities are responsible for the health protection in many agencies. The control of the indoor environment can be done in different ways and with different means. The aim of this report was to study in which way the inspectors made this kind of inspections and if there was anything in their approach that could be developed. A part of the aim of the report was to study how fast a clean surface in a school become dusty. Interviewes with healthinspectors in Uppsala, Håbo and Tierp was made. Together with them also some inspections were performed. To get a larger view of methods to investigate the indoor environment some inspections of schools and dwellings were done with an employee at the unit of Arbets- och miljömedicin at the University Hospital in Uppsala. The dust study was performed at two schools in Knivsta. The results were that the inspectors had well developed methods for assessings of the indoor environment. The approach differed in some matters between the larger and the smaller communities. Regardless of the size of the communities the inspectors rarely used instruments as a tool for the inspections. The communication and agreement between the inspectors was also shown as an important part in their work. In general the inspectors felt secure in their role and to make decisions. It appeared some shortcomings in the general advice and guidelines from the national board of health and welfare, which is the national supervisory authority that shall guide inspection of health protection. For example there was shown a lack in the guidelines regarding cleaning in schools and kindergardens. The study of dust in schools showed that there was more dust after five days than after one day.

  • 5. Adler, P H
    et al.
    Malmqvist, Björn
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Predation on black flies (Diptera: Simuliidae) by the carnivorous plant Pinguicula vulgaris (Lentibulariaceae) in northern Sweden2004Inngår i: Entomologica Fennica, ISSN 0785-8760, Vol. 15, 124-128 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 6.
    Agnemo, Elin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Avfall från dricksvattenkvalitetslaboratorium: En studie om avfallsklassning och hantering av m-Endo agar LES vid Stockholm Vatten.2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The purpose of the study was to determine how the waste from m-Endo agar LES (LesEndo) should be categorized and managed, due to its content of the carcinogenic substance basic red 9 in basic fuchsine. The information was obtained by studying legislation and a laboratory practical was performed to verify, if basic fuchsine could remain in LesEndo agar after being heated. This was important to know for the further interpretation how to categorize and manage the waste according to the legislation. LesEndo agar was autoclaved at 121 °C for 15 and 30 minutes. E. coli and coliform bacteria was put to grow on the LesEndo agar. The results from the study showed that all replicas had coliform colonies, which appeared with a metallic fuchsine-sheen. This verified that basic fuchsine was unchanged and that there was no significant difference in growth between replicas with heated agar and the control. The total concentration of basic fuchsine in LesEndo agar was 0.08%. To be categorized as hazardous waste the threshold value for basic red 9 is 0.1%. According to a strict interpretation of the legislation, waste from used LesEndo agar should not be categorized and managed as hazardous waste. However, evaporation has to be taken into consideration and the concentration may be above 0.1%. Therefore my evaluation is that waste from used LesEndo agar should be categorized and managed as hazardous waste to protect humans and the environment from being harmed.

  • 7.
    Ahlgren, Gunnel
    et al.
    Department of Ecology and Evolution (Limnology), Uppsala University, Uppsala, Sweden.
    Vrede, Tobias
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Goedkoop, Willem
    Department of Environmental Assessment, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
    Fatty Acid Ratios in Freshwater Fish, Zooplankton and Zoobenthos - Are There Specific Optima?2009Inngår i: Lipids in Aquatic Ecosystems / [ed] Martin Kainz, Michael T. Brett, Michael T. Arts, New York: Springer-Verlag New York, 2009, 147-178 s.Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    Two groups of polyunsaturated fatty acids (PUFA), termed omega-3 and omega-6 in food (or here as n-3 and n-6 PUFA, respectively), are essential for all vertebrates and probably also for nearly all invertebrates. The absolute concentrations of the different PUFA are important, as is an appropriate balance between the two. The optimal ratio of n-3/n-6 is not known for most organisms but is anticipated to be more or less species-specific (Sargent et al. 1995). The three most important PUFA in vertebrates are eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (ARA, 20:4n-6). Both EPA and ARA are precursors for biologically active eicosanoids that are vital components of cell membranes and play many dynamic roles in mediating and controlling a wide array of cellular activities (Crawford et al. 1989; Harrison 1990; Henderson et al. 1996; see Chap. 9). Since n-3 and n-6 PUFA cannot be synthesized de novo by most metazoans, they must be included in the diet, either as EPA, DHA and ARA, or as their precursors, such as α-linolenic acid (ALA, 18:3n-3, precursor of EPA and DHA) and linoleic acid (LIN, 18:2n-6, precursor of ARA) (Bell et al. 1986; Sargent et al. 1995). Both ALA and LIN are produced in the thylacoid membranes of algae and plants with chlorophyll (Sargent at al. 1987).

  • 8.
    Ahlinder, Jon
    et al.
    Division of CBRN Defence and Security, FOI, Swedish Defence Research Agency, Umeå, Sweden.
    Mathisen, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Sjödin, Andreas
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen. Division of CBRN Defence and Security, FOI, Swedish Defence Research Agency, Umeå, Sweden.
    Nilsson, Elin
    Division of CBRN Defence and Security, FOI, Swedish Defence Research Agency, Umeå, Sweden.
    Forsman, Mats
    Division of CBRN Defence and Security, FOI, Swedish Defence Research Agency, Umeå, Sweden.
    Andersson, Agneta
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Thelaus, Johanna
    Division of CBRN Defence and Security, FOI, Swedish Defence Research Agency, Umeå, Sweden.
    Oligotyping reveals divergent responses of predation resistant bacteria to aquatic productivity and plankton compositionManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Predation-resistance has been suggested to be a key for persistence of pathogenic bacteria in aquatic environments. Little is known about driving factors for different types of protozoa resistant bacteria (PRB). We studied if presence of PRB is linked to specific plankton taxa, the aquatic nutrient state, or predation pressure on bacteria. Nineteen freshwater systems were sampled and analyzed for PRB, plankton composition and physicochemical variables. Three PRB genera were identified; Pseudomonas, Mycobacterium and Rickettsia. Use of minimum entropy decomposition algorithm and phylogenetic analysis showed that different nodes (representing OTUs of high taxonomic resolution) matched to environmental isolates of the three genera. Links between the PRB genera and specific plankton taxa were found, but showed different relationships depending on if 18S rRNA OTU or microscopy data were used in the analysis. Mycobacterium spp. was negatively correlated to aquatic nutrient state, while Pseudomonas showed the opposite pattern. Rickettsia spp. was positively related to predation pressure on bacteria. Both Mycobacterium and Rickettsia were more abundant in systems with high eukaryotic diversity, while Pseudomonas occurred abundantly in waters with low prokaryotic diversity. The different drivers may be explained by varying ecological strategies, where Mycobacterium and Rickettsia are slow growing and have an intracellular life style, while Pseudomonas is fast growing and opportunistic. Here we give an insight to the possibilities of newly advanced methods such as sequencing and oligotyping to link potential pathogens with biomarkers. This as a tool to assist predictions of the occurrence and persistence of environmental pathogens.

  • 9.
    Ahlm, Kristoffer
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Prey specialization and diet of frogs in Borneo2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Earlier studies of the diet of frogs indicate that most adult frogs are mainly insectivorous. Overall, frogs are viewed more as generalists than specialists in terms of their diet. However, despite earlier studies, there are still gaps in our knowledge regarding what frogs tend to eat and the degree of specialization. The aim of this study was to investigate the diet choice of frogs in a tropical ecosystem. The present study was conducted in a well-known hotspot for frogs with 66 of the 156 known frog species in Borneo found in a protected area comprising of primary rainforest.

     

    Frogs were caught in the field and their stomachs were flushed. The stomach content was retrieved, sorted to prey categories, and the diet analysed. In addition, the frogs were identified to species level. The frogs belonged to five families: Bufonidae, Dicroglossidae, Megophryidae, Microhylidae and Ranidae. My results show that the most common food source was ants, which constituted 63.7 % of the total food for all studied frog families. Termites, beetles and spiders made up 11.7 %, 4.2 % and 2.8 % of the total prey, respectively. The results from the analysis of Shannon’s diversity index supported two diet specialist families, the Bufonidae and Megophridae, which had a significantly lower mean diversity index compared to the generalist Dicroglossidae. To better reveal differences in frog’s diet in this ecosystem, further studies using larger sample size are needed.

     

     

     

  • 10.
    Ahonen, Jani
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Korttidsregleringsmönster i Ångermanälvens avrinningsområde: Har elmarknadens avreglering påverkat regleringsintensiteten?2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The effects of the deregulation of the electricity market 1996 in Sweden on short-term hydropower regulation are unknown. This report investigates patterns in subdaily regulation in the Ångerman River Basin during the period 1993-2011. Differences in subdaily flows and zero flow events between the periods 1993-1995 and 1996-2011 were studied by analyzing hourly data from 8 regulated and 8 unregulated locations with four subdaily flow variation indices. No correlations between the market deregulation and the regulation intensity in the Ångerman River basin were detected. The number of days natural ranges of variability were exceeded and the magnitude of subdaily variation were significantly higher at regulated locations. Zero flow events increased substantially when the periods 1993-2007 and 2008-2011 were compared. Significant correlations were detected in the summer periods between dry years and high magnitudes for the indices that measured variation in volume and low magnitudes for subdaily flow reversals. Zero flow events in the summer periods increased during dry years if the period 2008-2011 were excluded. The major conclusions are that the deregulation of the electricity market has not affected the subdaily regulation of the Ångerman River and that the regulated sites show highly unnatural subdaily variations. Regulation intensity and zero flows events increases during summertime in dry years and the latter also increased substantially after 2007. The current regulation regime is considered harmful for riverine ecosystems and the high and increasing levels of subdaily flow alteration shows the urgent need of national directives for subdaily hydropower operation.

  • 11.
    Alapää, Pär
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Soil geochemical mapping of manganese in Norrbotten: Delineation of the spatial and statistical distribution of manganese and correlated elements in glacial tills2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Information from soil geochemical mapping programmes is useful within a number of different fields including for example mineral exploration and environmental research. The purpose of this thesis was to investigate the relationship between soil metal concentrations and geological factors such as bedrock lithology, structural geology, mineralizations etc. The study used data acquired in association with a nationwide soil geochemical mapping programme conducted by the Geological Survey of Sweden, SGU. These data contained both total element concentrations measured via X-ray fluorescence spectroscopy and acid leached concentrations measured with plasma technique. Basic statistical compilations were made, including classification of element concentrations into percentiles according to SGU standards, calculation of leachability and correlation analyses. Spatial analyses were also done, using GIS-software. The results showed that all investigated elements except zinc had elevated median values for total concentrations in the project area compared to the natural median values. The strongest correlation for total element concentrations was that between iron and cobalt with Spearman ρ=0.88. Furthermore, the results of this study indicated that sampling sites superimposing volcanic rocks contained the highest total concentrations of manganese. The results also suggested that manganese content increased with increasing age of the underlying bedrock. The highest median concentration of 0.80 g/kg was found in Archean rocks. Known mineralizations were often reflected in the form of positive element anomalies in the till geochemistry. The obtained results were also consistent with the average composition of the bedrock. No clear connections with any of the other investigated geological factors could be made.

  • 12. Albrectsen, B R
    et al.
    Gardfjell, H
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Ekologi, miljö och geovetenskap.
    Orians, C M
    Murray, B
    FRitz, R S
    Slugs, willow seedlings and nutrient fertilization: intrinsic vigor inversely affects palatability2004Inngår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 105, 268-278 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 13.
    Albrectsen, Benedicte R.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Björkén, Lars
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Varad, Akkamahadevi
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Hagner, Åsa
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wedin, Mats
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Jansson, Stefan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Endophytic fungi in European aspen (Populus tremula) leaves - diversity, detection, and a suggested correlation with herbivory resistance2010Inngår i: Fungal diversity, ISSN 1560-2745, E-ISSN 1878-9129, Vol. 41, nr 1, 17-28 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    According to the geographic mosaic theory of coevolution (GMTC), clines of traits reflecting local co-adaptation (including resistance genes) should be common between a host and its parasite and should persist across time. To test the GMTC-assumption of persistent clinal patterns we compared the natural prevalence of two parasites on aspen Populus tremula trees: mining moths of the genus Phyllocnistis and leaf rust Melampsora spp. Damage data were collated from the Swedish National Forest Damage Inventory (2004–2006). In addition, occurrence of the parasites was scored in field conditions in two common gardens in the north and south of Sweden over five growing seasons (2004–2008), then related to biomass (stem height and diameter) and to concentrations of eleven leaf phenolics. Phyllocnistis mainly occurred in the northern garden, a distribution range which was confirmed by the countrywide inventory, although Phyllocnistis was more abundant on southern clones, providing evidence for possible local maladaptation. Melampsora occurred all over the country and in both gardens, but built up more quickly on northern clones, which suggests a centre of local clone maladaptation in the north. Stem growth also followed a clinal pattern as did the concentration of three phenolic compounds: benzoic acid, catechin and cinnamic acid. However, only benzoic acid was related to parasite presence: negatively to Phyllocnistis and positively to Melampsora and it could thus be a potential trait under selection.

    In conclusion, clines of Phyllocnistis were stronger and more persistent compared to Melampsora, which showed contrasting clines of varying strength. Our data thus support the assumption of the GMTC model that clines exist in the border between hot and cold spots and that they may be less persistent for parasites with an elevated gene flow, and/or for parasites which cover relatively larger hot spots surrounded by fewer cold spots.

  • 14.
    Albrectsen, Benedicte R.
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Ericson, Lars
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Lundberg, Per
    Nutrient addition extends flowering display, which gets tracked by seed predators, but not by their parasitoids2008Inngår i: Oikos, Vol. 117, 473-480 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Although phenological matching between two and three trophic interactions has received some attention, it has largely been disregarded in explaining the lack of strong cascade dynamics in terrestrial systems. We studied the response of the specialist seed predator, Paroxyna plantaginis (Tephritidae) and associated generalist parasitoids (Chalcidoidea) to controlled fertilisation of individuals of naturally growing Tripolium vulgare (Asteraceae) on four island populations (Skeppsvik Archipelago, Sweden). We consistently found evidence of nutrient limitation: fertilised plants increased their biomass, produced more capitula (the oviposition units for tephritid flies), were more at risk of attack by the tephritids, and puparia were heavier in fertilised plants. During some parts of the season tephritids became more heavily parasitized, supporting the presence of cascade dynamics, however net parasitism over season decreased in response to nutrient addition. We found no evidence that capitulum size complicated parasitoid access to the tephritids, however the extended bud production prolonged the flowering season. Thus, tephritids utilized the surplus production of capitula throughout the entire season, while parasitoids did not expand their oviposition time window accordingly. Implications for top down regulation and cascade dynamics in the system are discussed.

  • 15.
    Alewell, C
    et al.
    Institute of Environmental Geosciences, University of Basel, Switzerland.
    Giesler, Reiner
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Klaminder, Jonatan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Leifeld, J
    Agroscope Reckenholz-Tanikon Research Station ART, Switzerland.
    Rollog, M
    Institute of Environmental Geosciences, University of Basel, Switzerland.
    Stable carbon isotopes as indicators for environmental change inpalsa peats2011Inngår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 8, 1769-1778 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Palsa peats are unique northern ecosystems formed under an arctic climate and characterized by a high biodiversity and sensitive ecology. The stability of the palsas are seriously threatened by climate warming which will change the permafrost dynamic and induce a degradation of the mires.

    We used stable carbon isotope depth profiles in two palsa mires of Northern Sweden to track environmental change during the formation of the mires. Soils dominated by aerobic degradation can be expected to have a clear increase of carbon isotopes (δ13C) with depth, due to preferential release of 12C during aerobic mineralization. In soils with suppressed degradation due to anoxic conditions, stable carbon isotope depth profiles are either more or less uniform indicating no or very low degradation or depth profiles turn to lighter values due to an enrichment of recalcitrant organic substances during anaerobic mineralisation which are depleted in 13C.

    The isotope depth profile of the peat in the water saturated depressions (hollows) at the yet undisturbed mire Storflaket indicated very low to no degradation but increased rates of anaerobic degradation at the Stordalen site. The latter might be induced by degradation of the permafrost cores in the uplifted areas (hummocks) and subsequent breaking and submerging of the hummock peat into the hollows due to climate warming. Carbon isotope depth profiles of hummocks indicated a turn from aerobic mineralisation to anaerobic degradation at a peat depth between 4 and 25 cm. The age of these turning points was 14C dated between 150 and 670 yr and could thus not be caused by anthropogenically induced climate change. We found the uplifting of the hummocks due to permafrost heave the most likely explanation for our findings. We thus concluded that differences in carbon isotope profiles of the hollows might point to the disturbance of the mires due to climate warming or due to differences in hydrology. The characteristic profiles of the hummocks are indicators for micro-geomorphic change during permafrost up heaving.

  • 16.
    Alewell, C
    et al.
    Institute of Environmental Geosciences, University of Basel, Switzerland.
    Giesler, Reiner
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Klaminder, Jonatan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Leifeld, J
    Agroscope Reckenholz-Tänikon Research Station ART, Switzerland.
    Rollog, M
    Institute of Environmental Geosciences, University of Basel, Switzerland.
    Stable carbon isotopes as indicators for micro-geomorphic changes in palsa peats2011Inngår i: Biogeoscience Discussions, ISSN 1810-6277, Vol. 8, nr 1, 527-548 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Palsa peats are unique northern ecosystems formed under an arctic climate and characterizedby an unique biodiversity and ecology. The stability of the palsas are seriouslythreatened by climate warming which will change the permafrost dynamic and5 results in degradation of the mires. We used stable carbon isotope depth profiles intwo palsa mires of Northern Sweden to track environmental change during the formationof the mires. Carbon isotope (13C) depth profile of the yet undisturbed mireStorflaket indicated very low to no degradation of the peat in the water saturated depressions(hollows) but increased rates of anaerobic degradation at the Stordalen site.10 The latter might be induced by degradation of the permafrost cores in the uplifted areas(hummocks) and subsequent braking and submerging of the hummock peat intothe hollows due to climate warming. Carbon isotope depth profiles of hummocks indicateda turn from aerobic mineralisation to anaerobic degradation at a peat depthbetween 4 to 25 cm. The age of these turning point was 14C dated between 150 and15 670 years and could thus not be caused by anthropogenically induced climate change.We found the uplifting of the hummocks due to permafrost heave the most likely explanationfor our findings. We thus concluded that differences in carbon isotope profiles ofthe hollows might point to the disturbance of the mires due to climate warming or dueto differences in hydrology. The characteristic profiles of the hummocks are indicators20 for micro-geomorphic change during permafrost up heaving.

  • 17.
    Algesten, Grete
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Brydsten, Lars
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jonsson, Per
    Institute of Applied Environmental Research, Stockholm University, Stockholm, Sweden.
    Kortelainen, Pirkko
    Finnish Environment Institute, P.O. Box 140, FIN-00251, Helsinki, Finland.
    Löfgren, Stefan
    Department of Environmental Assessment, SLU, P.O. Box 7050, Uppsala, Sweden.
    Rahm, Lars
    Department of Water and Environmental Studies, Linköping University, SE-58183 Linköping, Sweden.
    Räike, Antti
    Finnish Environment Institute, P.O. Box 140, FIN-00251, Helsinki, Finland.
    Sobek, Sebastian
    Institute for Aquatic Sciences and Water Pollution Control, Swiss Federal Institute of Technology Zurich (ETH), Universitätsstr. 16, CH-8092 Zurich, Switzerland.
    Tranvik, Lars
    Department of Ecology and Evolution, EBC, Uppsala University, SE-752 36 Uppsala, Sweden.
    Wikner, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Jansson, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Organic carbon budget for the Gulf of Bothnia2006Inngår i: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 63, nr 3-4, 155-161 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We calculated input of organic carbon to the unproductive, brackish water basin of the Gulf of Bothnia from rivers, point sources and the atmosphere. We also calculated the net exchange of organic carbon between the Gulf of Bothnia and the adjacent marine system, the Baltic Proper. We compared the input with sinks for organic carbon; permanent incorporation in sediments and mineralization and subsequent evasion of CO2 to the atmosphere. The major fluxes were riverine input (1500 Gg C year− 1), exchange with the Baltic Proper (depending on which of several possible DOC concentration differences between the basins that was used in the calculation, the flux varied between an outflow of 466 and an input of 950 Gg C year 1), sediment burial (1100 Gg C year− 1) and evasion to the atmosphere (3610 Gg C year− 1). The largest single net flux was the emission of CO2 to the atmosphere, mainly caused by bacterial mineralization of organic carbon. Input and output did not match in our budget which we ascribe uncertainties in the calculation of the exchange of organic carbon between the Gulf of Bothnia and the Baltic Proper, and the fact that CO2 emission, which in our calculation represented 1 year (2002) may have been overestimated in comparison with long-term means. We conclude that net heterotrophy of the Gulf of Bothnia was due to input of organic carbon from both the catchment and from the Baltic Proper and that the future degree of net heterotrophy will be sensible to both catchment export of organic carbon and to the ongoing eutrophication of the Baltic Proper.

  • 18.
    Algesten, Grete
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Sobek, Sebastian
    Bergström, Ann-Kristin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Jonsson, Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Tranvik, Lars J
    Jansson, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Contribution of sediment respiration to summer CO2 emission from boreal and subarctic lakes2005Inngår i: Microbial Ecology, ISSN 0095-3628, E-ISSN 1432-184X, Vol. 50, nr 4, 529-535 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We measured sediment production of carbon dioxide (CO(2)) and methane (CH(4)) and the net flux of CO(2) across the surfaces of 15 boreal and subarctic lakes of different humic contents. Sediment respiration measurements were made in situ under ambient light conditions. The flux of CO(2) between sediment and water varied between an uptake of 53 and an efflux of 182 mg C m(-2) day(-1) from the sediments. The mean respiration rate for sediments in contact with the upper mixed layer (SedR) was positively correlated to dissolved organic carbon (DOC) concentration in the water (r(2) = 0.61). The net flux of CO(2) across the lake surface [net ecosystem exchange (NEE)] was also closely correlated to DOC concentration in the upper mixed layer (r(2) = 0.73). The respiration in the water column was generally 10-fold higher per unit lake area compared to sediment respiration. Lakes with DOC concentrations <5.6 mg L(-1) had net consumption of CO(2) in the sediments, which we ascribe to benthic primary production. Only lakes with very low DOC concentrations were net autotrophic (<2.6 mg L(-1)) due to the dominance of dissolved allochthonous organic carbon in the water as an energy source for aquatic organisms. In addition to previous findings of allochthonous organic matter as an important driver of heterotrophic metabolism in the water column of lakes, this study suggests that sediment metabolism is also highly dependent on allochthonous carbon sources.

  • 19.
    Algesten, Grete
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Sobek, Sebastian
    Bergström, Ann-Kristin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ågren, Anneli
    Tranvik, Lars J
    Jansson, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Role of lakes for organic carbon cycling in the boreal zone2004Inngår i: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 10, nr 1, 141-147 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We calculated the carbon loss (mineralization plus sedimentation) and net CO2 escape to the atmosphere for 79 536 lakes and total running water in 21 major Scandinavian catchments (size range 437–48 263 km2). Between 30% and 80% of the total organic carbon that entered the freshwater ecosystems was lost in lakes. Mineralization in lakes and subsequent CO2 emission to the atmosphere was by far the most important carbon loss process. The withdrawal capacity of lakes on the catchment scale was closely correlated to the mean residence time of surface water in the catchment, and to some extent to the annual mean temperature represented by latitude. This result implies that variation of the hydrology can be a more important determinant of CO2 emission from lakes than temperature fluctuations. Mineralization of terrestrially derived organic carbon in lakes is an important regulator of organic carbon export to the sea and may affect the net exchange of CO2 between the atmosphere and the boreal landscape.

  • 20.
    Algesten, Grete
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wikner, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Sobek, Sobek
    Department of Limnology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden .
    Tranvik, Lars T.
    Department of Limnology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden .
    Jansson, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Seasonal variation of CO2 saturation in the Gulf of Bothnia: Indications of marine net heterotrophy2004Inngår i: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 18, 4021-4028 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Seasonal variation of pCO2 and primary and bacterioplankton production were measured in the Gulf of Bothnia during an annual cycle. Surface water was supersaturated with CO2 on an annual basis, indicating net heterotrophy and a source of CO2 to the atmosphere. However, the Gulf of Bothnia oscillated between being a sink and a source of CO2 over the studied period, largely decided by temporal variation in bacterial respiration (BR) and primary production (PP) in the water column above the pycnocline. The calculated annual respiration-production balance (BR-PP) was very similar to the estimated CO2 emission from the Gulf of Bothnia, which indicates that these processes were major determinants of the exchange of CO2 between water and atmosphere. The southern basin (the Bothnian Sea) had a lower net release of CO2 to the atmosphere than the northern Bothnian Bay (7.1 and 9.7 mmol C m−2 d−1, respectively), due to higher primary production, which to a larger extent balanced respiration in this basin.

  • 21. Aljetlawi, A A
    et al.
    Sparrevik, E
    Leonardsson, K
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Ekologi, miljö och geovetenskap.
    Prey-predator size-dependent functional response: derivation and rescaling to the real world2004Inngår i: J. Animal Ecology, Vol. 73, 239-252 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 22. Allan, Mohammed
    et al.
    Le Roux, Gael
    De Vleeschouwer, Francois
    Bindler, Richard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Blaauw, Maarten
    Piotrowska, Natalia
    Sikorski, Jaroslaw
    Fagel, Nathalie
    High-resolution reconstruction of atmospheric deposition of trace metals and metalloids since AD 1400 recorded by ombrotrophic peat cores in Hautes-Fagnes, Belgium2013Inngår i: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 178, 381-394 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The objective of our study was to determine the trace metal accumulation rates in the Misten bog, Hautes-Fagnes, Belgium, and assess these in relation to established histories of atmospheric emissions from anthropogenic sources. To address these aims we analyzed trace metals and metalloids (Pb, Cu, Ni, As, Sb, Cr, Co, V, Cd and Zn), as well as Pb isotopes, using XRF, Q-ICP-MS and MC-ICP-MS, respectively in two 40-cm peat sections, spanning the last 600 yr. The temporal increase of metal fluxes from the inception of the Industrial Revolution to the present varies by a factor of 5-50, with peak values found between AD 1930 and 1990. A cluster analysis combined with Pb isotopic composition allows the identification of the main sources of Pb and by inference of the other metals, which indicates that coal consumption and metallurgical activities were the predominant sources of pollution during the last 600 years.

    (c) 2013 Elsevier Ltd. All rights reserved.

  • 23.
    Almfelt, Josephine
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Ekologi, miljö och geovetenskap.
    Plastic acceleration of metamorphosis in the common frog (Rana temporaria) in response to pool drying: the effect of geographical isolationOppgave
  • 24. Almroth, B.C.
    et al.
    Sturve, J.
    Berglund, A.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Ekologi, miljö och geovetenskap.
    Forlin, L.
    Protein carbonyl's and tbars as biomarkers for oxidative damage in eelpout (Zoacers vivaparus)2006Inngår i: Marine Environmental Research, ISSN 0141-1136, E-ISSN 1879-0291, Vol. 62, nr Suppl. 1Artikkel i tidsskrift (Fagfellevurdert)
  • 25. Alonso, Carlos
    et al.
    Roman, Alfonso
    Bejarano, Maria Dolores
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Garcia de Jalon, Diego
    Carolli, Mauro
    A graphical approach to characterize sub-daily flow regimes and evaluate its alterations due to hydropeaking2017Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 574, 532-543 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Most flow regime characterizations focus on long time scale flow patterns, which are not precise enough to capture key components of short-term flow fluctuations. Recent proposed methods describing sub-daily flow fluctuations are focused on limited components of the flow regime being unable to fully represent it, or on the identification of peaking events based on subjectively defined thresholds, being unsuitable for evaluations of short-term flow regime alterations through comparisons between regulated and free-flowing rivers. This study aims to launch an innovative approach based on the visual display of quantitative information to address the challenge of the short-term hydrologic characterization and evaluation of alteration resulting from hydropeaking. We propose a graphical method to represent a discrete set of ecologically relevant indices that characterize and evaluate the alteration of sub-daily flow regimes. The frequency of occurrence of classified values of a descriptive hydrological variable is represented in a map-like graph where longitude, latitude and altitude represent the Julian day, the value of the variable and the frequency of occurrence, respectively. Subsequently, we tested the method on several rivers, both free-flowing and subjected to hydropower production. The advantages of our approach compared to other analytical methods are: (i) it displays a great amount of information without oversimplification; (ii) it takes into account changes in the intensity, timing and frequency of the sub-daily flows, without needing a priori defined thresholds to identify hydropeaking events; and (iii) it supports the Water Framework Directive goal. Specifically, results from applications of our graphical method agree with Sauterleute and Charmasson (2014) analytical method.

  • 26. Ampel, Linda
    et al.
    Bigler, Christian
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wohlfarth, Barbara
    Risberg, Jan
    Lotter, André F
    Veres, Daniel
    Modest summer temperature variability during DO cycles in western Europe2010Inngår i: Quaternary Science Reviews, ISSN 0277-3791, E-ISSN 1873-457X, Vol. 29, nr 11/12, 1322-1327 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Abrupt climatic shifts between cold stadials and warm interstadials, termed Dansgaard-Oeschger (DO) cycles, occurred frequently during the Last Glacial. Their imprint is registered in paleorecords worldwide, but little is known about the actual temperature change both annually and seasonally in different regions. A recent hypothesis based on modelling studies, suggests that DO cycles were characterised by distinct changes in seasonality in the Northern Hemisphere. The largest temperature change between stadial and interstadial phases would have occurred during the winter and spring seasons, whereas the summer seasons would have experienced a rather muted temperature shift. Here we present a temporally high-resolved reconstruction of summer temperatures for eastern France during a sequence of DO cycles between 36 and 18 thousand years before present. The reconstruction is based on fossil diatom assemblages from the paleolake Les Echets and indicates summer temperature changes of ca 0.5–2 °C between stadials and interstadials. This study is the first to reconstruct temperatures with a sufficient time resolution to investigate DO climate variability in continental Europe. It is therefore also the first proxy record that can test and support the hypothesis that temperature changes during DO cycles were modest during the summer season.

  • 27.
    Amundsson, Katharina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Control of marine plankton respiration: High temperature sensitivity at low temperatures influenced by substrate availability2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Temperature dependence of marine plankton respiration is an important factor in understanding the function and changes in the ecosystem of the ocean. The aim of this study is to test the temperature sensitivity (Q10) of plankton respiration. The oxygen optode method was used to measure plankton respiration. Natural water samples from the Baltic Sea was incubated at short (in situ +1, +2, +3°C) and long (in situ +5, +10, +20°C) temperature intervals with influence of dissolved organic matter (DOC). The Arrhenius equation and Q10-model was used to determine the temperature dependence (Q10) of respiration at different temperatures. There was a significant difference in Q10 between short temperature intervals at low temperatures (p=0,008) and long temperature intervals at higher temperatures. There was no significant difference between long and short temperature intervals when DOC was added (p=0,094). A significant effect could be seen with the DOC enrichment at low temperatures, where the Q10-values became significantly lower (p=0,002) after DOC addition. This effect could, however, not be seen at higher temperatures (p=0,117). Together with results from earlier studies it was concluded that the difference in temperature depends on the actual temperature and not the length of the interval. Lowered temperature dependence at raised DOC concentration, was the opposite of what was expected. The results suggest that the importance of temperature for CO2 emissions and development of hypoxia in the sea may have been underestimated.

  • 28. Anderson, K. E.
    et al.
    Nisbet, R. M.
    Diehl, S.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Ekologi, miljö och geovetenskap.
    Spatial scaling of consumer-resource interactions in advection-dominated systems2006Inngår i: American Naturalist, Vol. 168, nr 3, 358-372 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ecologists studying consumer-resource interactions in advection-dominated systems such as streams and rivers frequently seek to link the results of small-scale experiments with larger-scale patterns of distribution and abundance. Accomplishing this goal requires determining the characteristic scale, termed the response length, at which there is a shift from local dynamics dominated by advective dispersal to larger-scale dynamics dominated by births and deaths. Here, we model the dynamics of consumer-resource systems in a spatially variable, advective environment and show how consumer-resource interactions alter the response length relative to its single-species value. For one case involving a grazer that emigrates in response to high predator density, we quantify the changes using published data from small-scale experiments on aquatic invertebrates. Using Fourier analysis, we describe the responses of advection-dominated consumer-resource systems to spatially extended environmental variability in a way that involves explicit consideration of the response length. The patterns we derive for different consumer-resource systems exhibit important similarities in how component populations respond to spatial environmental variability affecting dispersal as opposed to demographic parameters.

  • 29. Anderson, K. E.
    et al.
    Nisbet, R. M.
    Diehl, S.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Ekologi, miljö och geovetenskap.
    Cooper, S. D.
    Scaling population responses to spatial environmental variability in advection-dominated systems2005Inngår i: Ecology Letters, Vol. 8, nr 9, 933-943 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We model the spatial dynamics of an open population of organisms that disperse solely through advection in order to understand responses to multiscale environmental variability. We show that the distance over which a population responds to a localized perturbation, called the response length, can be characterized as an organisms average lifetime dispersal distance, unless there is strong density-dependence in demographic or dispersal rates. Continuous spatial fluctuations in demographic rates at scales smaller than the response length will be largely averaged in the population distribution, whereas those in per capita emigration rates will be strongly tracked. We illustrate these results using a parameterized example to show how responses to environmental variability may differ in streams with different average current velocities. Our model suggests an approach to linking local dynamics dominated by dispersal processes to larger-scale dynamics dominated by births and deaths.

  • 30. Anderson, N. John
    et al.
    Saros, Jasmine E.
    Bullard, Joanna E.
    Cahoon, Sean M. P.
    Mcgowan, Suzanne
    Bagshaw, Elizabeth A.
    Barry, Christopher D.
    Bindler, Richard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Burpee, Benjamin T.
    Carrivick, Jonathan L.
    Fowler, Rachel A.
    Fox, Anthony D.
    Fritz, Sherilyn C.
    Giles, Madeleine E.
    Hamerlik, Ladislav
    Ingeman-Nielsen, Thomas
    Law, Antonia C.
    Mernild, Sebastian H.
    Northington, Robert M.
    Osburn, Christopher L.
    Pla-Rabes, Sergi
    Post, Eric
    Telling, Jon
    Stroud, David A.
    Whiteford, Erika J.
    Yallop, Marian L.
    Yde, Jacob C.
    The Arctic in the Twenty-First Century: Changing Biogeochemical Linkages across a Paraglacial Landscape of Greenland2017Inngår i: BioScience, ISSN 0006-3568, E-ISSN 1525-3244, Vol. 67, nr 2, 118-133 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Kangerlussuaq area of southwest Greenland encompasses diverse ecological, geomorphic, and climate gradients that function over a range of spatial and temporal scales. Ecosystems range from the microbial communities on the ice sheet and moisture-stressed terrestrial vegetation (and their associated herbivores) to freshwater and oligosaline lakes. These ecosystems are linked by a dynamic glacio-fluvial-aeolian geomorphic system that transports water, geological material, organic carbon and nutrients from the glacier surface to adjacent terrestrial and aquatic systems. This paraglacial system is now subject to substantial change because of rapid regional warming since 2000. Here, we describe changes in the eco-and geomorphic systems at a range of timescales and explore rapid future change in the links that integrate these systems. We highlight the importance of cross-system subsidies at the landscape scale and, importantly, how these might change in the near future as the Arctic is expected to continue to warm.

  • 31. Andersson , R.
    et al.
    Östlund, L.
    Törnlund, Erik
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Ekologi, miljö och geovetenskap.
    The last European landscape to be colonised: A case study of land-use change in the far north of Sweden 1850-19302005Inngår i: Environment and History, ISSN 0967-3407, E-ISSN 1752-7023, Vol. 11, nr 3, 293-318 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The agricultural colonisation of the interior of northern Sweden in the eighteenth and nineteenth centuries can be regarded as Europe's last colonising venture supported by an economy based on self-sufficiency. Nevertheless, nomadic Sami people have practised basic economic approaches to resources and environment in this region for thousands of years. The aim of this study was to analyse the swift land-use transition, from nomadic to agricultural, in the last colonised landscape of northern Sweden. Using historical documents and maps together with modern maps and a field survey, we wanted to link land-use patterns as strongly as possible to landscape features and ecosystems. Resource use of farmers and the native Samis showed many similarities with some important exceptions. Some obvious disparities seem to have evolved, mainly connected to the animal species that were domesticated. With the Sami people involved and interfering with the colonisation process, their use of resources contributed significantly to local economy and land use therefore became intensified. Interestingly, in the studied area the main driving force for establishment of new settlements was commercial forestry. However, in the last colonised landscape, forestry reached its physical limits, leaving mountain birch forests with evidence of traditional Sami land use and Sami historical traces.

  • 32.
    Andersson, Agneta
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Ett ekosystem i ständig förändring2014Inngår i: Havsutsikt Tema Hav och Klimat, nr 2, 9-11 s.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 33.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Ahlinder, Jon
    Division of CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE-901 82 Umeå, Sweden.
    Mathisen, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Bäckman, Stina
    Division of CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE-901 82 Umeå, Sweden.
    Nilsson, Elin
    Division of CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE-901 82 Umeå, Sweden.
    Hammarström, Moa
    Division of CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE-901 82 Umeå, Sweden.
    Sjödin, Andreas
    Division of CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE-901 82 Umeå, Sweden.
    Thelaus, Johanna
    Division of CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE-901 82 Umeå, Sweden.
    Aquatic ecosystems at risk for occurrence of pathogenic bacteriaManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    Pathogenic bacteria occur naturally in aquatic systems. Co-existence of bacteria and protozoa has led to development of predation resistance strategies, which is suggested to serve as a driver for evolution of pathogenic bacteria. However, the ecological mechanisms for selection for different types of predation resistant and pathogenic bacteria are poorly known. To disentangle effects from nutrient availability and protozoan predation pressure on the occurrence of varying predation resistant bacterial genera, an enrichment-dilution experiment was performed where an aquatic bacterial community was exposed to protozoa. Operational taxonomical units, specific for three predation resistant bacterial genera were identified; Pseudomonas, Rickettsia and Mycobacterium. These genera are also known to harbor species that are potentially pathogenic to mammals. Rickettsia and Mycobacterium were promoted where protozoa were abundant and the predation pressure high, while Pseudomonas dominated the bacterial community at the highest nutrient level where the predation pressure on bacteria were low. Our study thus indicates that waters of all nutrient states can harbor pathogenic bacteria, but that bacteria with different ecological strategies occur depending on nutrient level and perturbation. The generative model approach presented here provide a possibility to integrate environmental data in prediction models of pathogens in complex environments.

  • 34.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Hansen, W
    Wänstrand, I
    Huseby, S
    Wikner, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Strategi för kontrollerande övervakning av kustvatten i Bottenhavets vattendistrikt2008Rapport (Fagfellevurdert)
  • 35.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Hansen, Wenche
    Länsstyrelsen Västernorrland.
    Wänstrand, Ingrid
    Länsstyrelsen Gävleborg.
    Huseby, Siv
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Wikner, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Strategi för kontrollerande övervakning av Bottenhavets vattendistrikt2008Rapport (Annet vitenskapelig)
    Abstract [sv]

    Ett pelagialprogram har tagits fram för övervakning i relativt opåverkade referensområden i kustvattentyperna 16 t.o.m.19 i Bottemhavet. Programmet bör kunna ligga till grund för uppföljning av internationella, nationella och regionala miljömål samt följa upp ekologisk status. Den rumsliga variationen samt mellanårsvariationen hos pelagiala variabler i Bottenhavsområdet har använts som utgångspunkt för att beräkna provtagningsbehovet. Det föreslagna programmet innebär att mellan 48 och 60 provtagningar årsperiod, varefter ekologisk status kan bedömas. Designen gör det möjligt att med 80 % säkerhet bedöma ekologisk status med mätdata som ligger minst 20 % från klassgränserna. Mätprogrammet är designat för provtagningar -årsperiod. Stationer har slumpats ut i de olika typerna, och förslag på årliga provtagningslokaler anges i rapporten. Eftersom djupet vid de olika stationerna varierar, bör de flesta pelagiala variablerna provtas vid ett diskret djup i övre delen av vattenmassan, t.ex. 1 m djup. Av vetenskapliga och ekonomiska skäl är det viktigt att pelagialprogrammet samordnas för hela Bottenhavet.

    För mjukbottenfauna bedöms det befintliga integrerade programmet för trendanalys i Bottenhavet kunna tillgodose Vattendirektivets behov för kontrollerande övervakning i distriktet. Detta under förutsättning att Sundsvallsbuktens program fortsätter och att de nya nationella och regionala provtagningsområdena i södra Bottenhavet (Gräsö) etableras och drivs. Dimensioneringen av nuvarande nationellt och regionalt bottenfaunaprogram och områdesövervakning men har även visat sig vara väl anpassat för bedömningar inom ramen för Vattendirektivet. Enligt bedömningsgrunden bör minst 5 stationer användas för klassning av ekologisk status. Dessa stationer måste dock inte ligga inom samma vattenförekomst, utan kan vara lokaliserade i angränsande vattenförekomster. Den ekologiska statusen för mjukbottenfauna i enskilda vattenförekomster klassas genom extrapolering med hjälp av data från närbelägna områden med liknande bottenmiljö och påverkansgrad.

    Befintlig fiskebeståndsövervakning föreslås fortlöpa för att möjliggöra uppföljning av förändringar. En utökning av antalet övervakningsområden föreslås dock för att upprätta minst ett referensområde per inre och yttre kustvattentyp. En kombination av stratifierad och slumpmässig övervakning av fiskebestånden enligt nuvarande strategi föreslås, där djupintervallen stratifieras medan stationerna slumpas ut i respektive djupintervall.

    Provfiske och provtagning för miljögiftsanalys av fisk bör samordnas till samma provtagningstillfälle. Vidare bör den modell för samfinansiering och samordning som idag tillämpas av kustlänen i Bottniska viken för övervakning av fiskbestånd, samt och miljögiftsövervakning av fisk, fortlöpa även framöver.

    De ämnen som ingår i det pågående nationella programmet för miljögifter i fisk bör mätas även i de nya föreslagna områdena. När EU:s dotterdirektiv för prioriterade ämnen är beslutat och Vattenmyndigheterna fastställt miljökvalitetsnormer för särskilda förorenande ämnen, bör en översyn göras och ytterligare ämnen som är aktuella för Bottenhavet införlivas i övervakningsprogrammet. Miljögiftsövervakning i fisk bedöms kunna mätas med ett maximalt avstånd på 75 km mellan stationsområdena. Bedömning och extrapolera mätvärdena.

    För samtliga delprogram har en grova uppskattningar av kostnader för genomförandet gjorts.

  • 36.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Höglander, Helena
    Karlsson, Chatarina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Huseby, Siv
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Key role of phosphorus and nitrogen in regulating cyanobacterial community composition in the northern Baltic Sea2015Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 164, 161-171 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite cyanobacteria being a key phytoplankton group in the Baltic Sea, the factors governing their community structure are still poorly understood. Here, we studied the occurrence of the orders Chroococcales, Oscillatoriales and Nostocales, and potentially explanatory variables at five locations in the northern Baltic Sea from June–September, 1998–2012. Cyanobacteria constituted 1–36% of the total phytoplankton biomass along the north–south gradient. In the Bothnian Bay, Chroococcales and Oscillatoriales dominated the cyanobacterial community, whereas in the Bothnian Sea and northern Baltic Proper, Nostocales was the dominant group. The dominance of Chroococcales was coupled to low salinity and low total phosphorus, whereas Oscillatoriales correlated with high total nitrogen and low salinity. Nostocales correlated to high total phosphorus, inorganic phosphorus and salinity. Chroococcales showed an increase over time in the offshore Bothnian Bay, whereas Nostocales increased in the coastal Bothnian Sea and coastal Baltic Proper. The increase of Nostocales in the coastal Bothnian Sea was explained by a rise in total phosphorus and decrease in dissolved inorganic nitrogen compared to an increase of total nitrogen and phosphorus in the coastal Baltic Proper. No significant trends were observed in the cyanobacterial community in the offshore Bothnian Sea and the offshore northern Baltic Proper. We concluded that Chroococcales may be a useful indicator for increased phosphorus levels in waters with low phosphorus concentrations, whereas Nostocales could be used as a quality indicator for increasing phosphorus concentrations in waters with low inorganic N/P ratios (&lt;20), such as in the coastal Bothnian Sea and Baltic Proper.

  • 37.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Joanna, Paczkowska
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Brugel, Sonia
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Rowe, Owen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Figueroa, Daniela
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Kratzer, Susanne
    Stockholm University Institutionen för ekologi miljö och botanik 106 91 Stockholm.
    Marked impact of allochthonous dissolved organic matter on estuarine primary and bacterial productionManuskript (preprint) (Annet vitenskapelig)
  • 38.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Jurgensone, Iveta
    Rowe, Owen F.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Simonelli, Paolo
    Bignert, Anders
    Lundberg, Erik
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Karlsson, Jan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Can Humic Water Discharge Counteract Eutrophication in Coastal Waters?2013Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, nr 4, e61293- s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A common and established view is that increased inputs of nutrients to the sea, for example via river flooding, will cause eutrophication and phytoplankton blooms in coastal areas. We here show that this concept may be questioned in certain scenarios. Climate change has been predicted to cause increased inflow of freshwater to coastal areas in northern Europe. River waters in these areas are often brown from the presence of high concentrations of allochthonous dissolved organic carbon ( humic carbon), in addition to nitrogen and phosphorus. In this study we investigated whether increased inputs of humic carbon can change the structure and production of the pelagic food web in the recipient seawater. In a mesocosm experiment unfiltered seawater from the northern Baltic Sea was fertilized with inorganic nutrients and humic carbon (CNP), and only with inorganic nutrients (NP). The system responded differently to the humic carbon addition. In NP treatments bacterial, phytoplankton and zooplankton production increased and the systems turned net autotrophic, whereas the CNP-treatment only bacterial and zooplankton production increased driving the system to net heterotrophy. The size-structure of the food web showed large variations in the different treatments. In the enriched NP treatments the phytoplankton community was dominated by filamentous >20 mu m algae, while in the CNP treatments the phytoplankton was dominated by picocyanobacteria <5 mu m. Our results suggest that climate change scenarios, resulting in increased humic-rich river inflow, may counteract eutrophication in coastal waters, leading to a promotion of the microbial food web and other heterotrophic organisms, driving the recipient coastal waters to net-heterotrophy.

  • 39.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Karlsson, C
    Hajdu, S
    Höglander, H
    Skjevik, A-T
    Pelagial biologi / växtplankton2010Inngår i: Havet: Om miljötillståndet i svenska havsområden, Stockholm: Naturvårdsverket, 2010, 32-33 s.Kapittel i bok, del av antologi (Fagfellevurdert)
  • 40.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Karlsson, K
    Huseby, S
    Höglander, H
    Mer fosfor ger mer cyanobakterier i norra Östersjön.2013Inngår i: HavetArtikkel, forskningsoversikt (Fagfellevurdert)
  • 41.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Meier, H.E. Markus
    Ripszam, Matyas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Rowe, Owen
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Wikner, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Haglund, Peter
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Eilola, Kari
    Legrand, Catherine
    Figueroa, Daniela
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Paczkowska, Joanna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Lindehoff, Elin
    Tysklind, Mats
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Elmgren, Ragnar
    Projected future climate change and Baltic Sea ecosystem management2015Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 44, nr Suppl 3, S345-S356 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Climate change is likely to have large effectson the Baltic Sea ecosystem. Simulations indicate 2–4 Cwarming and 50–80 % decrease in ice cover by 2100.Precipitation may increase *30 % in the north, causingincreased land runoff of allochthonous organic matter(AOM) and organic pollutants and decreased salinity.Coupled physical–biogeochemical models indicate that, inthe south, bottom-water anoxia may spread, reducing codrecruitment and increasing sediment phosphorus release,thus promoting cyanobacterial blooms. In the north,heterotrophic bacteria will be favored by AOM, whilephytoplankton production may be reduced. Extra trophiclevels in the food web may increase energy losses andconsequently reduce fish production. Future managementof the Baltic Sea must consider the effects of climatechange on the ecosystem dynamics and functions, as wellas the effects of anthropogenic nutrient and pollutant load.Monitoring should have a holistic approach, encompassingboth autotrophic (phytoplankton) and heterotrophic (e.g.,bacterial) processes.

  • 42.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Meier, M
    Hur påverkas östersjön?2010Inngår i: Sverige i nytt klimat – våtvarm utmaning, Stockholm: Forskningsrådet Formas, 2010, 117-132 s.Kapittel i bok, del av antologi (Fagfellevurdert)
  • 43.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Samuelsson, K
    Haecky, P
    Albertsson, J
    Changes in the pelagic microbial food web due to artificial eutrophication2006Inngår i: Aquat Ecol, Vol. 40, 299-313 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 44.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF). Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Selstam, Eva
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysiologisk botanik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå Plant Science Centre (UPSC).
    Hagström, Åke
    Vertical transport of lipid in seawater1993Inngår i: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 98, nr 1-2, 149-155 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lipids in seawater act as solvents and transporters of lipophilic organic pollutants. To investigate a possible transport route of lipophilic pollutants, the vertical flux of lipid was quantified during an annual cycle in the northern Baltic Sea. The lipid content in both sedimenting material and different size fractions of seawater was analyzed. During the year, 8 g lipid m-2 sedimented out from the photic zone to the benthic system. The sedimentation of lipid accounted for 300 to 400 % of the average standing stock of pelagic lipid and was concentrated in the spring bloom period (April-June) when 70 % of the total lipid sedimentation occurred. About 30 % of the produced pelagic lipid settled out from the system. In seawater the lipid maximum occurred at the end of the spring bloom, shortly after nutrient depletion, indicating a stress response in the algae. Since lipid sedimentation is concentrated in the spring bloom, removal of lipophilic organic pollutants may be important during this period.

  • 45.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Tamminen, Timo
    Lehtinen, Sirpa
    Jürgens, Klaus
    Labrenz, Matthias
    Viitasalo, Markku
    The pelagic food web2017Inngår i: Biological oceanography of the Baltic sea / [ed] Pauline Snoeijs, Hendrik Schubert, Teresa Radziejewska, Dordrecht: Springer Netherlands, 2017, 281-332 s.Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]
    1. Environmental drivers and food web structure in the pelagic zone vary from south to north in the Baltic Sea. 
    2. While nitrogen is generally the limiting nutrient for primary production in the Baltic Sea, phosphorus is the limiting nutrient in the Bothnian Bay. 
    3. In the Gulf of Bothnia the food web is to a large extent driven by terrestrial allochthonous material, while autochthonous production dominates in the other parts of the Baltic Sea. 
    4. Changes in bacterioplankton, protist and zooplankton community composition from south to north are mainly driven by salinity. 
    5. Bacteria are crucial constituents of the pelagic food web (microbial loop) and in oxygen-poor and anoxic bottom waters where they mediate element transformations. 
    6. Diatoms and dinoflagellates are the major primary producers in the pelagic zone. Summer blooms of diazotrophic (nitrogen-fixing) filamentous cyanobacteria are typical of the Baltic Sea, especially in the Baltic Sea proper and the Gulf of Finland. 
    7. The mesozooplankton (mainly copepods and cladocerans) channel energy from primary producers and the microbial food web to fish and finally to the top predators in the pelagic system (waterbirds and mammals). 
    8. Herring and sprat populations are affected by the foraging intensity of their main predator (cod), and therefore the environmental conditions that affect cod may also influence mesozooplankton due to food web effects "cascading down the food web". 
    9. Anthropogenic pressures, such as overexploitation of fish stocks, eutrophication, climate change, introduction of non-indigenous species and contamination of top predators by hazardous substances, cause changes in the pelagic food web that may have consequences for the balance and stability of the whole ecosystem.
  • 46.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Wikner, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Klimatförändringar kan leda till mindre fisk i havet2016Inngår i: Havet: om miljötillståndet i i svenska havsområden. 2015/2016, Göteborg: Havs- och vattenmyndigheten , 2016, 25-28 s.Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 47.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Wikner, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Pelagisk biologi2004Inngår i: Bottniska viken: årsrapport från den marina miljöövervakningen. 2003, Skydd av havsområden gagnar fisken, Hörnefors: Umeå marina forskningscentrum (UMF) , 2004, 11-13 s.Kapittel i bok, del av antologi (Fagfellevurdert)
  • 48.
    Andersson, Amanda
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Hållbar utveckling i kommuner: En studie om hur kommunerna i Norr- och Västerbotten arbetar med folkhälsomål och miljökvalitetsmål2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The purpose of this study was to investigate if the municipalities in Norrbotten and Västerbotten integrate the national environmental objectives and public health objectives in their work to achieve a sustainable development. Furthermore the purpose was to suggest different methods and tools to develop an integrated way of working with the objectives. Methods used were a literature study and a questionnaire, which was sent to people responsible for the objectives in each municipality. The result of this study indicates that most of the municipalities in Norrbotten and Västerbotten work extensively with environmental and public health objectives, but not in an integrated way. Methods like information in schools, closures and projects are used to implement the objectives in different municipal units. The result also indicates that public health is more considered in the municipalities than the environmental objectives. However, there was a will to expand the local work with the environmental objectives in the future. The conclusion of this study is that improvements can be done to develop and integrate public health and environmental issues in the municipalities in Norrbotten and Västerbotten. An integrated way of working with the objectives could include usage of indicators, such as unemployment or air particles, to measure the development and prioritize actions. It could also include participation in different networks to exchange experience within or between municipalities.

  • 49.
    Andersson, Anna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Övervakning och uppföljning av utter i Västerbottens län2005Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
  • 50.
    Andersson, Bea Angelica
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
    Analysis of Selection and Genetic Drift in a Dioecious Plant: Spatial Genetic Structure and Selection in Phenotypic Traits in a Young Island Population of Silene dioica2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Selection and genetic drift are often competing forces in shaping genetic structure in populations. Genetic drift will often effectively cancel out the effect of selection when population sizes are small, such as in colonizing island populations. On a small island in the Skeppsvik Archipelago in northern Sweden, a newly founded population of Silene dioica has been monitored since it first established around 1993. Though inhabiting an area of merely 173 m2, the population has been shown to exhibit a genetically differentiated patch structure where closely related individuals are tightly grouped, distanced from other family groups. In this study, the effect of selection was evaluated as compared to that of genetic drift. Variation in phenotypic traits in flowers, leaves and stalks were compared to that of neutral markers, in the form of PST and FST measures, to assess a measure of what proportion of differentiation among patches in phenotypic traits could not be attributed to genetic drift. Males and females were analysed separately to obtain measures of sex specific selection. Signs of divergent and stabilizing selection were found in several traits in both males and females despite the small spatial scale and short time since colonization. Further analysis is needed to assess explanations for trait divergence among patches and direction of selection.

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