hkr.sePublikasjoner
Endre søk
Begrens søket
12 1 - 50 of 92
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Alho, Jussi S.
    et al.
    Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki.
    Herczeg, Gábor
    Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki.
    Söderman, Fredrik
    Population and Conservation Biology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University.
    Laurilla, Anssi
    Population and Conservation Biology, Department of Ecology and Evolution, Evolutionary Biology Centre, Uppsala University.
    Jönsson, K. Ingemar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Merilä, Juha
    Ecological Genetics Research Unit, Department of Biosciences, University of Helsinki.
    Increasing melanism along a latitudinal gradient in a widespread amphibian: local adaptation, ontogenic or environmental plasticity?2010Inngår i: BMC Evolutionary Biology, ISSN 1471-2148, E-ISSN 1471-2148, Vol. 10, 317- s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BackgroundThe thermal benefits of melanism in ectothermic animals are widely recognized, but relatively little is known about population differentiation in the degree of melanism along thermal gradients, and the relative contributions of genetic vs. environmental components into the level of melanism expressed. We investigated variation in the degree of melanism in the common frog (Rana temporaria; an active heliotherm thermoregulator) by comparing the degree of melanism (i) among twelve populations spanning over 1500 km long latitudinal gradient across the Scandinavian Peninsula and (ii) between two populations from latitudinal extremes subjected to larval temperature treatments in a common garden experiment.

    ResultsWe found that the degree of melanism increased steeply in the wild as a function of latitude. Comparison of the degree of population differentiation in melanism (PST) and neutral marker loci (FST) revealed that the PST > FST, indicating that the differences cannot be explained by random genetic drift alone. However, the latitudinal trend observed in the wild was not present in the common garden data, suggesting that the cline in nature is not attributable to direct genetic differences.

    ConclusionsAs straightforward local adaptation can be ruled out, the observed trend is likely to result from environment-driven phenotypic plasticity or ontogenetic plasticity coupled with population differences in age structure. In general, our results provide an example how phenotypic plasticity or even plain ontogeny can drive latitudinal clines and result in patterns perfectly matching the genetic differences expected under adaptive hypotheses. 

  • 2.
    Arvidsson, Fredrik
    et al.
    Lund University.
    Jonsson, Lars J.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Birkhofer, Klaus
    Lund University.
    Geographic location, not forest type, affects the diversity of spider communities sampled with malaise traps in Sweden2016Inngår i: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 53, nr 3-4, 215-227 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The latitudinal diversity gradient predicts higher species richness at lower latitudes. Here, we utilize the data from a long-term monitoring with malaise traps to analyse if spider communities in Sweden are affected by geographic gradients and if these effects hold independent of forest type. The species richness and the effective number of species in spider communities were not significantly related to the latitudinal gradient. The effective number of species and the taxonomic distinctness of spider communities were related to longitude, with a higher number, but fewer related species in western parts of Sweden. The species and family composition were significantly related to latitude independent of forest type, with a dominance of Linyphiidae individuals and species in the north. Our study demonstrates the suitability of malaise trap sampling to contribute to a better understanding of local spider communities, as several rare and locally new species were recorded in this study.

  • 3.
    Arzel, Céline
    et al.
    University of Turku.
    Dessborn, Lisa
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Pöysä, Hannu
    Joensuu Game and Fisheries Research.
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Nummi, Petri
    University of Helsinki.
    Sjöberg, Kjell
    Swedish University of Agricultural Sciences, Umeå.
    Early springs and breeding performance in two sympatric duck species with different migration strategies2014Inngår i: Ibis, ISSN 0019-1019, E-ISSN 1474-919X, Vol. 156, nr 2, 288-298 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The capacity of migratory species to adapt to climate change may depend on their migratory and reproductive strategies. For example, reproductive output is likely to be influenced by how well migration and nesting are timed to temporal patterns of food abundance, or by temperature variations during the brood rearing phase. Based on two decades (1988–2009) of waterfowl counts from a boreal catchment in southern Finland we assessed how variation in ice break-up date affected nesting phenology and breeding success in two sympatric duck species, Mallard Anas platyrhynchos and Eurasian Teal Anas crecca. In Fennoscandia these species have similar breeding habitat requirements but differ in migration distance; Teal migrate roughly seven times as far as do Mallard. Annual ice break-up date was used as a proxy of spring ‘earliness’ to test the potential effect of climate change on hatching timing and breeding performance. Both species were capable of adapting their nesting phenology, and bred earlier in years when spring was early. However, the interval from ice break-up to hatching tended to be longer in early springs in both species, so that broods hatched relatively later than in late springs. Ice break-up date did not appear to influence annual number of broods per pair or annual mean brood size in either species. Our study therefore does not suggest that breeding performance in Teal and Mallard is negatively affected by advancement of ice break-up at the population level. However, both species showed a within-season decline in brood size with increasing interval between ice break-up and hatching. Our study therefore highlights a disparity between individuals in their capacity to adjust to ice break-up date, late breeders having a lower breeding success than early breeders. We speculate that breeding success of both species may therefore decline should a consistent trend towards earlier springs occur.

  • 4. Back, C
    et al.
    Boisvert, J
    Lacoursière, Jean O.
    Charpentier, G
    High-dosage treatment of a Quebec stream with Bacillus thuringiensis serovar. israelensis: efficacy against black fly larvae (Diptera, Simuliidae) and impact on nontarget insects1985Inngår i: Canadian Entomologist, ISSN 0008-347X, E-ISSN 1918-3240, Vol. 117, nr 12, 1523-1534 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A typical lake outlet of the Canadian Shield was treated for 15 min with a high dose (5.28 g/L s−1 of discharge) of Teknar®, a commercial formulation of Bacillus thuringiensis serovar. israelensis. Efficacy on Simuliidae larvae and impact on non-target aquatic insects of this stream were monitored using drift nets, counting plates, and artificial turf substrates along a 1000-m section downstream of the site of application. Compared with a 4-day pre-treatment average for 12-h sampling periods, drift of Simuliidae increased from 64 to 92 ×, with shorter peaks of 133–184 ×, 2–6 h after treatment. There was no evident drift increase in larvae of Ephemeroptera, Plecoptera, Trichoptera, Chironomidae, or dipterous pupae, but larvae of Blephariceridae (Diptera) were severely affected as their drift was increased by up to 50 × and remained high for 3 days. After 30 h the mortality of Simuliidae on counting plates ranged from 95 to 82% in the first 300 m, with detachment rates of 78.5–46.5%. Densities of non-target insect larvae were not reduced on the artificial substrates, except for 2 genera of Chironomidae (Eukiefferella and Polypedilum) which were reduced 26 to 39% of their original density. Drifting larvae of 1 chironomid genus (Phaenopsectra) also showed symptoms of toxemia by B.t.i. The main impact of the treatment was thus seen in 2 Nematocera families (Chironomidae and Blephariceridae) which were mainly exposed to B.t.i. sedimented on the bottom of the stream or attached to periphyton growing on rocks.

  • 5.
    Bengtsson, Daniel
    et al.
    Linnaeus University.
    Avril, Alexis
    Linnaeus University.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Söderquist, Pär
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Norevik, Gabriel
    Ottenby Bird Observatory.
    Tolf, Conny
    Linnaeus University.
    Safi, Kamran
    Max Planck Institute for Ornithology.
    Fiedler, Wolfgang
    Max Planck Institute for Ornithology.
    Wikelski, Martin
    Max Planck Institute for Ornithology.
    Olsen, Bjorn
    Uppsala University.
    Waldenstrom, Jonas
    Linnaeus University.
    Movements, home-range size and habitat selection of mallards during autumn migration2014Inngår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, nr 6, e100764- s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mallard (Anas platyrhynchos) is a focal species in game management, epidemiology and ornithology, but comparably little research has focused on the ecology of the migration seasons. We studied habitat use, time-budgets, home-range sizes, habitat selection, and movements based on spatial data collected with GPS devices attached to wild mallards trapped at an autumn stopover site in the Northwest European flyway. Sixteen individuals (13 males, 3 females) were followed for 15-38 days in October to December 2010. Forty-nine percent (SD = 8.4%) of the ducks' total time, and 85% of the day-time (SD = 28.3%), was spent at sheltered reefs and bays on the coast. Two ducks used ponds, rather than coast, as day-roosts instead. Mallards spent most of the night (76% of total time, SD = 15.8%) on wetlands, mainly on alvar steppe, or in various flooded areas (e.g. coastal meadows). Crop fields with maize were also selectively utilized. Movements between roosting and foraging areas mainly took place at dawn and dusk, and the home-ranges observed in our study are among the largest ever documented for mallards (mean = 6,859 ha; SD = 5,872 ha). This study provides insights into relatively unknown aspects of mallard ecology. The fact that autumn-staging migratory mallards have a well-developed diel activity pattern tightly linked to the use of specific habitats has implications for wetland management, hunting and conservation, as well as for the epidemiology of diseases shared between wildlife and domestic animals.

  • 6.
    Bengtsson, Daniel
    et al.
    Linnaeus University.
    Safi, Kamran
    Tyskland.
    Avril, Alexis
    Linnaeus University.
    Fiedler, Wolfgang
    Tyskland.
    Wikelski, Martin
    Tyskland.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Tolf, Conny
    Linnaeus University.
    Olsen, Björn
    Uppsala University.
    Waldenström, Jonas
    Linnaeus University.
    Does influenza A virus infection affect movement behaviour during stopover in its wild reservoir host?2016Inngår i: Royal Society Open Science, E-ISSN 2054-5703, Vol. 3, nr 2, 150633Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The last decade has seen a surge in research on avian influenza A viruses (IAVs), in part fuelled by the emergence, spread and potential zoonotic importance of highly pathogenic virus subtypes. The mallard (Anas platyrhynchos) is the most numerous and widespread dabbling duck in the world, and one of the most important natural hosts for studying IAV transmission dynamics. In order to predict the likelihood of IAV transmission between individual ducks and to other hosts, as well as between geographical regions, it is important to understand how IAV infection affects the host. In this study, we analysed the movements of 40 mallards equipped with GPS transmitters and three-dimensional accelerometers, of which 20 were naturally infected with low pathogenic avian influenza virus (LPAIV), at a major stopover site in the Northwest European flyway. Movements differed substantially between day and night, as well as between mallards returning to the capture site and those feeding in natural habitats. However, movement patterns did not differ between LPAIV infected and uninfected birds. Hence, LPAIV infection probably does not affect mallard movements during stopover, with high possibility of virus spread along the migration route as a consequence.

  • 7. Bengtsson, Daniel
    et al.
    Waldenström, Jonas
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Änders rörelser kartlagda2014Inngår i: Vår fågelvärld, ISSN 0042-2649, Vol. 73, nr 5, 46-48 s.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 8.
    Bertolani, Roberto
    et al.
    Italien.
    Guidetti, Roberto
    Italien.
    Jönsson, K. Ingemar
    Lund University.
    Altiero, Tiziana
    Italien.
    Boschini, Deborah
    Rebecchi, Lorena
    Italien.
    Experiences with dormancy in tardigrades2004Inngår i: Journal of limnology, ISSN 1129-5767, E-ISSN 1723-8633, Vol. 63, nr Suppl. 1, 16-25 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Tardigrades often colonise extreme habitats, in which they survive using both types of dormancy: quiescence and diapause. Together with nematodes and bdelloid rotifers, tardigrades are known to enter quiescence (with several forms of cryptobiosis: anhydrobiosis, cryobiosis, anoxybiosis, osmobiosis) at any stage of their life cycle, from egg to adult. Entering anhydrobiosis, tardigrades contract their body into a so-called tun, loosing most of their free and bound water (>95%), synthesizing cell protectants (e.g., trehalose, glycerol, heat shock proteins) and strongly reducing or suspending their metabolism. Our research on cryptobiosis focused on some ecological and evolutionary aspects. We evaluated: i) the long-term anhydrobiotic survival by comparing quantitative data on recovery from naturally induced desiccation in several species of tardigrades; ii) differences in survival patterns between species and populations by experimentally inducing anhydrobiosis and cryobiosis; iii) phenotypic factors affecting anhydrobiotic survival. As regards diapause, we considered encystment and eggs. Encystment involves at least the synthesis of new cuticular structures. Morphological changes during cyst formation are more complex than those involved in tun formation. We analyzed more in detail encystment processes, comparing a semiterrestrial with a limnic species. Several inter-specific differences have been identified, other than the production of two types of cysts in the semiterrestrial species. Our analysis of life history traits of a laboratory reared strain of a soil tardigrade revealed a particular hatching phenology that involved the production of both subitaneous and resting eggs. The latter need a cue to hatch (dehydration followed by re-hydration). In addition, the evolutionary meaning of dormancy in tardigrades is discussed

  • 9.
    Biederstädt, Jana
    Högskolan Kristianstad, Sektionen för lärande och miljö.
    Landskapsförändringar och deras påverkan på dagens biodiversitetsmönster hos kärlväxter i ett skånskt jordbrukslandskap2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I detta arbete studerades landskapsförändringar, i synnerhet olika typer av gräsmarkshabitat i fråga om artinnehåll och rikedom samt hur dagens diversitetsmönster har påverkats av den historiska markanvändningen. Undersökningsområdet har en area av ca 143 ha och är beläget i nordöstra Skåne. Resultatet visade att områdets areal av naturliga gräsmarker var mest omfattande kring 1783/98 och minst 1926-23. De naturliga gräsmarkernas omfattning har nästan halverats från slutet av 1700-talet till idag. Andelen betesmark som har hävdats från 1700-talets slut till 2014 utgör dock inte mer än 11 % av betesmarkernas totala areal. Väg- och dikesren uppvisade störst andel arter som var gemensamma med naturbetesmarkernas; minst var andelen i kultiverad gräsmark. Artrikedomen var minst lika hög i vägren, dikesren och skogsbryn som i naturbetesmarken medan den var lägre i kuliverad gräsmark. Artrikedomen var högst på vägrenen.

  • 10.
    Brodin, Anders
    et al.
    Lund University.
    Jönsson, K. Ingemar
    Lund University.
    Holmgren, Noél
    University of Skövde.
    Optimal energy allocation and behaviour in female raptorial birds during the nestling period2003Inngår i: Ecoscience, ISSN 1195-6860, Vol. 10, nr 2, 140-150 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In many raptors and owls the male is the main provider of food in the early phase of the nestling period while the female incubates the eggs and broods the young. In the nestling period the female often helps the male to feed the young, but the factors affecting whether and when she leaves the brood to hunt have not been investigated in detail. We present a dynamic state variable model that analyses female behaviour and fat storage dynamics over the nestling period. The results show that in the first half of the nestling period the female faces a conflict between the need to brood the young and the need to hunt to provision them with food. This conflict arises because the energy needs of the young peak early in the nestling period, at a time when they still cannot thermoregulate and therefore need brooding from the female. The most critical period is the second nestling week, when both female and nestling fat reserves will decrease to low levels. Large female fat reserves in the early nestling period provide a solution to this conflict and are essential for successful breeding. Stochasticity in male provisioning is thus not needed to explain why females should be fat when the eggs hatch. Under normal circumstances, the female broods during the first two weeks and leaves the young only if hunting is absolutely necessary. After the second week the energy requirements are relaxed, and whether the female assists the male in hunting or not depends on factors such as male hunting success, environmental stochasticity, and energy requirements of the young. Our model provides a framework for empirical investigations on female behaviour during breeding in raptors, owls, and other birds with marked division of labour.

  • 11. Callaghan, Terry V.
    et al.
    Tweedie, Craig E.
    Akerman, Jonas
    Andrews, Christopher
    Bergstedt, Johan
    Butler, Malcolm G.
    Christensen, Torben R.
    Cooley, Dorothy
    Dahlberg, Ulrika
    Danby, Ryan K.
    Daniels, Fred J. A.
    de Molenaar, Johannes G.
    Dick, Jan
    Mortensen, Christian Ebbe
    Ebert-May, Diane
    Emanuelsson, Urban
    Swedish Biodiversity Centre, Uppsala.
    Eriksson, Hakan
    Hedenas, Henrik
    Henry, Greg. H. R.
    Hik, David S.
    Hobbie, John E.
    Jantze, Elin J.
    Jaspers, Cornelia
    Johansson, Cecilia
    Johansson, Margareta
    Johnson, David R.
    Johnstone, Jill F.
    Jonasson, Christer
    Kennedy, Catherine
    Kenney, Alice J.
    Keuper, Frida
    Koh, Saewan
    Krebs, Charles J.
    Lantuit, Hugues
    Lara, Mark J.
    Lin, David
    Lougheed, Vanessa L.
    Madsen, Jesper
    Matveyeva, Nadya
    McEwen, Daniel C.
    Myers-Smith, Isla H.
    Narozhniy, Yuriy K.
    Olsson, Håkan
    Pohjola, Veijo A.
    Price, Larry W.
    Riget, Frank
    Rundqvist, Sara
    Sandstroem, Anneli
    Tamstorf, Mikkel
    Van Bogaert, Rik
    Villarreal, Sandra
    Webber, Patrick J.
    Zemtsov, Valeriy A.
    Multi-Decadal Changes in Tundra Environments and Ecosystems: Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF)2011Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, nr 6, 705-716 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in sub-arctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies.

  • 12.
    Carlsson, Nils O L
    et al.
    Lunds universitet.
    Lacoursière, Jean O.
    Lunds universitet.
    Herbivory on aquatic vascular plants by the introduced golden apple snail (Pomacea canaliculata) in Lao PDR2005Inngår i: Biological Invasions, ISSN 1387-3547, E-ISSN 1573-1464, Vol. 7, nr 2, 233-241 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effect of naturally found densities of the exotic and herbivorous golden apple snail (Pomacea canaliculata) on three dominant aquatic plants – duckweed (Lemna minor), water hyacinth (Eichhornia crassipes) and morning glory (Ipomoea aquatica) – was assessed in a wetland survey and quantified in a field experiment in Laos in southeast Asia. Snail grazing reduced plant biomass, but plant species were differently affected by grazing. Duckweed had almost disappeared after 6 and water hyacinth after 21 days, whereas morning glory remained at 80% of initial biomass after 32 days. Snail growth was lowest on morning glory and, when all plant species were simultaneously presented to snails, this plant was not preferred. We suggest that the negative effect the golden apple snail had on the growth of these plant species in field enclosures is present in the natural environment as well. This new and intense herbivory could have serious negative effects on invaded freshwater ecosystems in this region.

  • 13.
    Chauvet, Eric
    et al.
    Frankrike.
    Ferreira, V.
    Portugal.
    Giller, P. S.
    Irland.
    McKie, B. G.
    SLU, Uppsala.
    Tiegs, S. D.
    USA.
    Woodward, G.
    Storbritannien.
    Elosegi, A.
    Spanien.
    Dobson, M.
    Storbritannien.
    Fleituch, T.
    Polen.
    Graca, M. A. S.
    Portugal.
    Gulis, V.
    USA.
    Hladyz, S.
    Australien.
    Lacoursière, Jean O.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Lecerf, A.
    Frankrike.
    Pozo, J.
    Spanien.
    Preda, E.
    Rumänien.
    Riipinen, M.
    Storbritannien.
    RisŸnoveanu, G.
    Rumänien.
    Vadineanu, A.
    Rumänien.
    Vought, Lena B. M.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Gessner, M. O.
    Tyskland.
    Litter decomposition as an indicator of stream ecosystem functioning at local-to-continental scales: insights from the European RivFunction project2016Inngår i: Large-scale ecology: model systems to global perspectives / [ed] Alex J. Dumbrell, Rebecca L. Kordas; Woodward, Guy, London: Academic Press , 2016, Vol. 55, 99-182 s.Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    RivFunction is a pan-European initiative that started in 2002 and was aimed at establishing a novel functional-based approach to assessing the ecological status of rivers. Litter decomposition was chosen as the focal process because it plays a central role in stream ecosystems and is easy to study in the field. Impacts of two stressors that occur across the continent, nutrient pollution and modified riparian vegetation, were examined at > 200 paired sites in nine European ecoregions. In response to the former, decomposition was dramatically slowed at both extremes of a 1000-fold nutrient gradient, indicating nutrient limitation in unpolluted sites, highly variable responses across Europe in moderately impacted streams, and inhibition via associated toxic and additional stressors in highly polluted streams. Riparian forest modification by clear cutting or replacement of natural vegetation by plantations (e.g. conifers, eucalyptus) or pasture produced similarly complex responses. Clear effects caused by specific riparian disturbances were observed in regionally focused studies, but general trends across different types of riparian modifications were not apparent, in part possibly because of important indirect effects. Complementary field and laboratory experiments were undertaken to tease apart the mechanistic drivers of the continental scale field bioassays by addressing the influence of litter, fungal and detritivore diversity. These revealed generally weak and context-dependent effects on decomposition, suggesting high levels of redundancy (and hence potential insurance mechanisms that can mitigate a degree of species loss) within the food web. Reduced species richness consistently increased decomposition variability, if not the absolute rate. Further field studies were aimed at identifying important sources of this variability (e.g. litter quality, temporal variability) to help constrain ranges of predicted decomposition rates in different field situations. Thus, although many details still need to be resolved, litter decomposition holds considerable potential in some circumstances to capture impairment of stream ecosystem functioning. For instance, species traits associated with the body size and metabolic capacity of the consumers were often the main driver at local scales, and these were often translated into important determinants of otherwise apparently contingent effects at larger scales. Key insights gained from conducting continental scale studies included resolving the apparent paradox of inconsistent relationships between nutrients and decomposition rates, as the full complex multidimensional picture emerged from the large-scale dataset, of which only seemingly contradictory fragments had been seen previously.

  • 14.
    Cifuentes de Gramajo, Luisa
    Högskolan Kristianstad, Sektionen för lärande och miljö.
    Nejayote produced at household level by Mayan women in Guatemala: is it a threat to aquatic ecosystems or a resource for food security?2011Independent thesis Advanced level (degree of Master (Two Years)), 10 poäng / 15 hpOppgave
    Abstract [en]

    The aim of this study was to find out if nejayote produced at household level in Guatemala represents a threat to aquatic ecosystems and, if so, propose sustainable processing, reuse and disposal methods. First, all aspects related to nejayote production were explored. This study presents combined results from literature study on corn consumption and Guatemalan demography, a survey to Guatemalan women of all ethnical groups, nixtamalization replica and solids removal experiments and laboratory analysis. Findings indicate that the source of nejayote are approximate 600 000 tones of corn nixtamalized yearly by Mayan women from the rural areas of Guatemala to prepare tortillas for a population of about 5 000 000. From this activity approximately 300 000 tones of concentrated nejayote are produced and 800 000 tones of water are polluted yearly. Approximate 63% of these volumes are discharged into water ecosystems without treatment due to lack of knowledge of its potential negative impact or reuse properties. The study was done on nejayote produced at national level, but the isolation of the Mayan population within less than 20% of the national territory, suggests higher punctuality of nejayote discharges. Chemical and physical analyses made to samples from the nixtamalization replica confirmed its similarity to industrial nejayote, which has proven to be highly pollutant due to high content of organic matter from corn grain pericarp and germ. Concentrations ranges from 200 to 300 ppm of nitrogen, 160 to 190 ppm of phosphorus and 25 000 to 28 000 ppm of organic matter make it a potential fertilizer or soil conditioner. Studies indicate that it can be safely reused as supplementary food for chickens and pigs, to prepare additional corn based foods for humans or it could be safely discharged into ponds, wetlands or pits to minimize any environmental impact. Although findings point to nejayote as a potential aquatic ecosystem pollutant, this depends on the capacity of the specific recipient aquatic ecosystem to adsorb and process the nutrients and on the volumes and concentration of nutrients of the nejayote discharged that might vary from household to household. However, the nutrient rich nejayote can be seen as a potential resource, instead of a pollutant, to improve the nutritional, social and economical conditions of the Mayan populations. Specially women, an isolated segment of society that lacks opportunities and who, according to findings of this study, start processing corn into tortillas from early childhood and continue throughout all their lifetime without any benefit on return.

  • 15.
    Dessborn, Lisa
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Hessel, Rebecca
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Geese as vectors of nitrogen and phosphorus to freshwater systems2016Inngår i: INLAND WATERS, ISSN 2044-2041, E-ISSN 2044-205X, Vol. 6, nr 1, 111-122 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many goose populations have increased dramatically over the past decades, which may influence inland waters used as roost sites. We reviewed the role of geese in the influx of nitrogen and phosphorus to freshwater systems. Several methods have been used to estimate guanotrophication impacts of geese. Water and sediment analysis have been conducted in areas of high and low geese presence; however, productive wetlands tend to attract more birds, and the causality is therefore ambiguous. Faecal addition experiments have attempted to estimate the impacts of droppings on water chemistry, sediments, algal growth, or invertebrate densities. The most common method of estimating goose guanotrophication is by extrapolation, usually based on multiplication of faecal production and its nutrient content. Based on such studies and those including information about daily migration patterns, we developed an approach to improve estimates of the nutrient contribution of geese. The relative role of geese in wetland eutrophication is also affected by the influx from alternative sources. The greatest guanotrophication impacts are likely found in areas with few alternative nutrient sources and with large goose flocks. Limited inflow and outflow of a freshwater system or a scarcity of wetland roosts may also increase problems at a local scale. Although several studies have looked at the impacts of geese on, for example, water chemistry or soil sediments, the effects are often smaller than expected, in part because no study to date has assessed the ecosystem response by including impacts on all levels, including water nutrient levels, nutrient sedimentation, chlorophyll content, and zooplankton response.

  • 16.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Density-dependent nest predation in mallards Anas platyhynchos: patterns and implications2006Konferansepaper (Fagfellevurdert)
  • 17.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö.
    Konstgjorda reden ger riktiga svar2011Inngår i: Svensk Jakt, Vol. 1, 92-94 s.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Häckningen är en känslig och farlig fas i fåglarnas årliga cykel. Många rovdjur utgör ett hot mot ägg och ungar. Viltforskare vid Högskolan Kristianstad berättar här om nya rön om samspelet mellan gräsänder och de rovdjur som rövar deras bon.

  • 18.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Nummi, Petri
    Finland.
    Pöysä, Hannu
    Finland.
    Sjöberg, Kjell
    SLU.
    Density dependent breeding success in mallards2003Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Breeding success in wild mallards was studied on small eutrophic nemoral lakes in a two-year cross-over experiment in which wing-clipped conspecifics were added to increase pair density. The number of wild mallards that came to the lakes to nest (prior to introductions) did not differ between years. Introduction treatment led to a significant reduction in brood number in wild mallards, but it did not alter the number of stage 2+ ducklings finally produced on a lake. Introduction had no effect on lake utilization by broods, ducklings and non-breeding adults (cumulative days over the entire breeding season). Abundance of invertebrate prey differed greatly among lakes, but it did not correlate with breeding success. Breeding success was thus subject to sequential density-dependence; i.e. a lower number of broods still produced the same number of 2+ ducklings. We speculate that predation is the most likely process behind both patterns. We conclude that late and snapshot measures of duckling productivity may mask density dependent population processes of fundamental importance to regulation and harvest policy.

  • 19.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Nummi, Petri
    Pöysä, Hannu
    Sjöberg, Kjell
    Farligt att vara andägg2002Inngår i: Svensk jakt, ISSN 0039-6583, Vol. 140, nr 10, 18-20 s.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 20.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Pöysä, Hannu
    Finska vilt- & fiskeriforskningsinstitutet, Joensuu.
    Nummi, Petri
    Helsingfors universitet.
    Sjöberg, Kjell
    Sveriges lantbruksuniversitet, Umeå.
    Hur många får ligga i orubbat bo?2003Inngår i: Vår fågelvärld, ISSN 0042-2649, nr 3, 28-29 s.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 21.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Sjöberg, Kjell
    Nummi, Petri
    Pöysä, Hannu
    Finns det mer andrum?2005Inngår i: Svensk jakt, ISSN 0039-6583, Vol. 143, nr 8, 80-82 s.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 22.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Hessel, Rebecca
    Fox, Anthony David
    Department of Bioscience, Aarhus University.
    Dalby, Lars
    Department of Bioscience, Aarhus University.
    Interpreting seasonal range shifts in migratory birds: a critical assessment of 'short-stopping' and a suggested terminology2014Inngår i: Journal of Ornithology = Journal fur Ornithologie, ISSN 0021-8375, E-ISSN 1439-0361, Vol. 155, nr 3, 571-579 s.Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The term 'short-stopping' is increasingly used in ecology to describe spatio-temporal changes in occurrence of migratory species. Spurred by the insight that it has been used in a variety of contexts, we reviewed its use in avian ecology. A literature search yielded 59 papers explicitly treating short-stopping in birds, most of them in peer-reviewed journals. The term was first used in 1967 to describe a northward shift in wintering Canada Geese in North America and has been used with increasing frequency to the present day. Geese dominate the short-stopping literature, which is confined to the northern hemisphere. Short-stopping has been used to describe (1) a shortened autumn migration that results in a wintering distribution closer to breeding areas, (2) a shortened spring migration that results in a breeding distribution closer to wintering areas, and (3) a delay in autumn migration that leads to a perceived reduced abundance in some part of the winter range. We advocate that short-stopping should be used only to describe (1) range shifts that involve shortening of the migratory corridor, and that they are qualified explicitly by season (i.e. breeding/winter) and degree (i.e. full or partial range shift). In other cases of breeding, wintering or entire range shifts where the migratory corridor is elongated or remains the same, we recommend using the term 'range shift', qualified by season, geography and orientation (i.e. the direction of the range shift). We also discuss the need for spatially explicit avian count monitoring mechanisms (rather than capture-recapture or hunting bag data) designed specifically to track such changes in distribution in the future.

  • 23.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Nummi, Petri
    Pöysä, Hannu
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Sjöberg, Kjell
    Krickan - okänd kändis som vet att välja rätt sjö2005Inngår i: Vår fågelvärld, ISSN 0042-2649, Vol. 64, nr 3, 32-33 s.Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 24.
    Elmberg, Johan
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Söderquist, Pär
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Thulin, Carl-Gustaf
    SLU, Umeå.
    Champagnon, Jocelyn
    Frankrike.
    Guillemain, Matthieu
    Frankrike.
    Kreisinger, Jakub
    Tjeckien.
    Prins, H. H. T.
    Nederländerna.
    Crooijmans, R. P. M. A.
    Nederländerna.
    Kraus, R. H. S.
    Tyskland.
    Farmed European mallards are genetically different and cause introgression in the wild population following releases2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The practice of restocking already viable populations to increase harvest potential has since long been common in forestry, fisheries and wildlife management. The potential risks of restocking native species have long been overshadowed by the related issue of invasive alien species. However, during the last decade releases of native species with potentially non-native genome have received more attention. A suitable model to study genetic effects of large-scale releases of native species is the Mallard Anas platyrhynchos, being the most widespread duck in the world, largely migratory, and an important quarry species. More than 3 million unfledged hatchlings are released each year around Europe to increase local harvest. The aims of this study were to determine if wild and released farmed Mallards differ genetically, if there are signs of previous or ongoing introgression between wild and farmed birds, and if the genetic structure of the wild Mallard population has changed since large-scale releases started in Europe in the 1970s. Using 360 Single Nucleotide Polymorphisms (SNPs) we found that the genetic structure differed among historical wild, present-day wild, and farmed Mallards in Europe. We also found signs of introgression in the wild Mallard population, that is, individuals with a genetic background of farmed stock are part of the present free-living population. Although only a small proportion of the released Mallards appears to survive to merge with the free-living breeding population, their numbers are still so large that the genetic impact may have significance for the wild population in terms of individual survival and longterm fitness.

  • 25.
    Forkman, Jonatan
    Högskolan Kristianstad, Sektionen för lärande och miljö.
    Spindelfaunan i granplanteringar av olika åldrar: En undersökning från södra Skåne2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    To determine whether the spider communities in spruce Picea abies plantations in southern Sweden differ between trees of various ages, the spiders from minor, young and older trees has been collected during May and June 2016. The minor trees were 1.5–2.0 m, the young trees were 19–20 m and the older trees were over 22 m high. The spiders were collected from five plantations of each age category and from ten trees in each plantation. The spiders from ten of the dead branches inside of each older plantation were collected as well. 59 different species were found and all together 970 spider specimens were collected. The results showed many different things, for example that the species on the dead branches were mainly web spiders and that many of the species on the minor trees prefer the field layer as habitat. My study was compared to three other spider studies, one from Sweden, one from the Czech Republic and one from Norway. The comparison showed differences in the collected spider species which could be explained by the various methods used in the different studies and whether the spiders in the study had been collected during early summer or throughout the whole season. The spiders collected in this study could in the future be used to detect changes in the spider fauna caused by climate change.  

  • 26.
    Fox, Anthony D.
    et al.
    Aarhus University.
    Jonsson, Jon Einar
    University of Iceland.
    Aarvak, Tomas
    Norwegian Ornithological Society .
    Bregnballe, Thomas
    Aarhus University.
    Christensen, Thomas Kjaer
    Aarhus University.
    Clausen, Kevin Kuhlmann
    Aarhus University.
    Clausen, Preben
    Aarhus University.
    Dalby, Lars
    Aarhus University.
    Holm, Thomas Eske
    Aarhus University.
    Pavon-Jordan, Diego
    University of Helsinki.
    Laursen, Karsten
    Aarhus University.
    Lehikoinen, Aleksi
    University of Helsinki.
    Lorentsen, Svein-Hakon
    Norwegian Institute for Nature Research.
    Moller, Anders Pape
    University of Paris .
    Nordstrom, Mikael
    Metsahallitus Pk & Wildlife, Finland.
    Ost, Markus
    Åbo Akademi University.
    Soderquist, Par
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Therkildsen, Ole Roland
    Aarhus University.
    Current and potential threats to Nordic duck populations - a horizon scanning exercise2015Inngår i: Annales Zoologici Fennici, ISSN 0003-455X, E-ISSN 1797-2450, Vol. 52, nr 4, 193-220 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We review the current and future threats to duck populations that breed, stage, moult and/or winter in the Nordic countries. Migratory duck species are sensitive indicators of their changing environment, and their societal value confirms the need to translate signals from changes in their distribution, status and abundance into a better understanding of changes occurring in their wetland environments. We used expert opinion to highlight 25 major areas of anthropogenic change (and touch briefly on potential mitigation measures through nature restoration and reserve management projects) that we consider key issues likely to influence Nordic duck populations now and in the near future to stimulate debate, discussion and further research. We believe such reviews are essential in contributing to development of successful management policy as well as stimulating specific research to support the maintenance of duck species in favourable future conservation status in the face of multiple population pressures and drivers.

  • 27.
    Guillemain, Matthieu
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice La Tour du Valat, Le Sambuc, Arles.
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Gauthier-Clerc, Michel
    Centre de Recherche de la Tour du Valat Le Sambuc, Arles.
    Massez, Grégoire
    Les Marais du Vigueirat Mas Thibert, Arles .
    Hearn, Richard
    Wildfowl & Wetlands Trust, Slimbridge, Gloucester.
    Champagnon, Jocelyn
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice La Tour du Valat, Le Sambuc, Arles .
    Simon, Géraldine
    Centre de Recherche de la Tour du Valat Le Sambuc, Arles .
    Wintering French mallard and teal are heavier and in better body condition than 30 years ago: effects of a changing environment?2010Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 39, nr 2, 170-180 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Animal populations are exposed to large-scale anthropogenic impact from e.g. climate change, habitat alteration and supplemental stocking. All of these may affect body condition in wintering dabbling ducks, which in turn may affect an individual's survival and reproductive success. The aim of this study was to assess whether there have been morphometric changes in Mallard (Anas platyrhynchos) and Teal (Anas crecca) over the last 30 years at a major wintering site. Body mass and condition increased from the 1950s-1960s to the 2000s in both species. The increase in body mass amounted to as much as 11.7%, with no corresponding change in body size. Improved body condition was maintained from early to mid-winter, but then converged with historical values for late winter. Our interpretation is that increasingly benign ambient winter conditions permit ducks to maintain better energetic "safety margins" throughout winter, and that converging spring departure values may be related to evolutionary flight energetic optima. The observed changes are consistent with large-scale climate amelioration and local/regional habitat improvement (both anthropogenic).

  • 28.
    Guillemain, Matthieu
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Pöysä, Hannu
    Finnish Game and Fisheries Research Institute, Joensuu Game and Fisheries Research.
    Fox, Anthony D.
    Thomas Eske Holm & Thomas Kjær Christensen, Department of Bioscience, Aarhus University.
    Arzel, Céline
    Department of Biology, Section of Ecology, University of Turku.
    Dessborn, Lisa
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Ekroos, Johan
    Centre for Environmental and Climate Research, Lund.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Eske Holm, Thomas
    Thomas Eske Holm & Thomas Kjær Christensen, Department of Bioscience, Aarhus University.
    Kjær Christensen, Thomas
    Thomas Eske Holm & Thomas Kjær Christensen, Department of Bioscience, Aarhus University.
    Lehikoinen, Aleksi
    Department of Biological and Environmental Sciences, University of Helsinki.
    Mitchell, Carl
    Wildfowl & Wetlands Trust, Slimbridge.
    Rintala, Jukka
    Finnish Game and Fisheries Research Institute, Helsinki.
    Pape Møller, Anders
    Laboratoire Ecologie Systématique et Evolution (UMR 8079), Université Paris-Sud XI, Orsay.
    Effects of climate change on European ducks: what do we know and what do we need to know?2013Inngår i: Wildlife Biology, ISSN 0909-6396, E-ISSN 1903-220X, Vol. 19, nr 4, 404-419 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The consequences of climate change for bird populations have received much attention in recent decades, especially amongst cavity-nesting songbirds, yet little has been written on ducks (Anatidae) despite these being major elements of wetland diversity and important quarry species. This paper reviews the major known consequences of climate change for birds in general, and relates these to the limited information available specifically for ducks. Climate change can influence migration distance and phenology, potentially affecting patterns of mortality, as well as distribution and reproductive success in ducks. Studies addressing effects of climate change are, however, restricted to very few duck species, including mallardAnas platyrhynchos and common eider Somateria mollissima. Shifts in winter duck distributions have been observed, whereas the mismatch hypothesis (mistiming between the periods of peak energy requirements for young and the peak of seasonal food availability) has received limited support with regard to ducks. We propose a range of monitoring initiatives, including population surveys, breeding success monitoring schemes and individual duck marking, which should later be integrated through population modelling and adaptive management to fill these gaps.

  • 29.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Strandängarna i Kristianstads Vattenrike – hotade “hot spots”2015Inngår i: Forskningsmiljön Man & Biosphere Health: Högskolan Kristianstads miljöforskning i biosfärområde Kristianstads Vattenrike / [ed] Ingemar Jönsson, Kristianstad: Kristianstads kommun , 2015, 7-11 s.Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [sv]

    På relativt kort tid har flera arter strandängsvadare minskat dramatiskt i Kristianstads Vattenrike. Pågående forskning bedrivs för att utröna om nedgångarna kan ha orsakats av faktorer längre ner i näringsväven. I speciellt fokus för forskningen är produktionen av vegetation och ryggradslösa djur.

  • 30.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Institutionen för matematik och naturvetenskap.
    Survival patterns and density-dependent processes in breeding mallards Anas platyrhynchos2007Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Measuring and assessing vital rates such as births and deaths are prerequisites for understanding population dynamics. Vital rates may be affected by the density of individuals, even though the importance of density dependence on population dynamics has been debated for a long time. The mallard Anas platyrhynchos is one of the foremost game species in the Holarctic, with millions of birds in hunters’ bags annually. Still, basic knowledge about regulation of mallards’ vital rates is poor, and experimental studies on this topic are rare.

    In this thesis I have studied survival patterns and density dependence in mallards breeding in Sweden and Finland. Long-term ringing data from both countries were analysed for mortality patterns and causation, as well as for e.g. survival rate estimation. Most of the studies were, though, experiments run over two years involving manipulations of the density of nests, broods and/or adults, in southern and northern Sweden, comprising different biotic regions. Common response variables were survival of nests, ducklings and hens, mainly analysed with program MARK.

    About 90% of the recovered mallards in Finland and Sweden were hunting kills. However, survival rates were high, ranging from 0.66 to 0.81 for most groups (sex*age). The generality of density dependence was evident since such processes were detected in all studies. Consequently, depredation rate was higher in high nest density compared to low nest density. Survival of ducklings was density-dependent in both boreal and nemoral biotic regions, with food limitation being evident in the former region but not in the latter. In spite of their generality, density-dependent patterns varied within as well between years, and for nest predation rates also between landscape types.

    The findings about density dependence in breeding mallards in this thesis are novel since they are based on experiments. They are potentially of general interest for management because they embrace a variety of lakes in two geographically distant areas, each being representative for large temperate areas in the northern hemisphere. Detection of density dependence at the local scale may be important at larger scales, too, following the principle of ‘ideal preemptive distribution’ in a source-sink dynamic system.

  • 31.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Vem äter vad på Håslövs ängar?: mätningar av betestryck med kopplingar till det ekologiska samhället2013Konferansepaper (Annet (populærvitenskap, debatt, mm))
  • 32.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Density-dependent nest predation in dabbling ducks2002Konferansepaper (Fagfellevurdert)
  • 33.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Predation regulates the survival of mallard nests as revealed by an experiment in two landscape types2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Ecological theory frequently postulates that most animal species are subject to density-dependent mechanisms in some stage of the year or life. However, few avian studies have succeeded to give evidence for regulatory mechanisms by replicated experiments in natural habitats. Breeding success is to a great extent determined by conditions during the nesting period and the major cause of nesting failure is nest predation. In addition, predators may possibly regulate fluctuating populations and to test the hypothesis that nest survival is negatively density-dependent we conducted an experiment with manipulated densities of semi-natural Mallard nests and adult pairs using 32 small to medium sized lakes (~3-5 hectares) in southern Sweden during two nesting seasons (2003-2004). Predicting that predation rates are higher in open compared to more vegetated habitats, half of the lakes were in agricultural and the other half in forest landscapes. Using real Mallard eggs, nests were constructed in two densities; either 2 nests per lake (low density) or 8 nests per lake (high density). Model fitting in program MARK revealed that nest survival was negatively affected by nest density but not by pair density. Further, predation rates were much higher in agricultural landscapes than in forested. The effects of nest density and habitat were consistent in the two years. Covariates added to the model matrix revealed a negative effect of other waterfowl present on the lakes and a positive effect of study day. However, the number of avian predators observed at the lakes did not affect survival. Our experiment is the first to demonstrate density-dependent nest predation in Mallard. The consistency of the density effect between years and habitats shows that regulatory mechanisms may be truly significant for Mallard, possibly affecting population dynamics of the species.

  • 34.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Pöysä, Hannu
    Joensuu Game and Fisheries Research, Finnish Game and Fisheries Research Institute.
    Sjöberg, Kjell
    Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, Umeå.
    Dessborn, Lisa
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Arzel, Céline
    Section of Ecology, Department of Biology, Turku University.
    Density dependence in ducks: a review of the evidence2013Inngår i: European Journal of Wildlife Research, ISSN 1612-4642, E-ISSN 1439-0574, Vol. 59, nr 3, 305-321 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Density dependence (DD) is a central concept in population ecology and in the management of harvested populations. For example, DD underpins the idea of additive versus compensatory mortality and is a tenet in the paradigm of resource limitation and regulation. Yet the prevalence and importance of DD remains disputed in most organisms, including ducks, which are focal in game management, conservation and zoonotic diseases. Based on 154 data entries from 54 studies in the peer-reviewed literature, we here synthesize and evaluate the prevalence of DD in breeding ducks in relation to (1) species and guild (dabbling versus diving ducks), (2) stage in the breeding cycle (nesting, duckling, recruitment) or, alternatively, in terms of population dynamics, (3) study type (descriptive/nonmanipulative versus experimental), (4) continent (Europe versus North America), (5) spatial level (wetland, landscape, regional, continental) and (6) biome (tundra, boreal, nemoral, prairie, mediterranean). One conclusion from this review is that it is difficult to find general patterns about the prevalence of DD unless data are broken down to subsets, for example, to stage or spatial level. With respect to stage, DD effects occur at all stages of the breeding cycle. During the nesting and duckling stages, the frequency of cases detecting versus not detecting DD is roughly the same. However, in cases referring to the recruitment stage, i.e. to survival of fledged ducks until 1 year old at the most, DD was the rule, suggesting that DD processes may operate mainly outside the breeding season. Further subdivision of data shows that spatial scale is important to the prevalence of DD in nesting ducks—rare on the wetland level and more common on higher spatial levels. In studies of population dynamics (i.e. based on time series data only), DD was more often found in diving than in dabbling ducks. This corroborates previous suggestions that dabbling ducks largely should be considered as r-selected species, in contrast to more K-selected diving ducks, which start to reproduce at an older age and often breed in more stable wetland environments where resources may be easier to track and populations thus often are closer to carrying capacity. However, the picture of DD in ducks is far from complete, and knowledge gaps for future studies to address include: (a) data from Russia, which holds a large part of the breeding ducks in the Northern hemisphere, (b) experimental studies on more species to separate density-dependent factors from other drivers of population change and to tease apart spatial and temporal interactions in the underlying processes, (c) time series analyses addressing population dynamics, especially from outside North America, (d) studies relating duck numbers to limiting resources, which arguably is the most relevant measure of density, (e) the timing of DD processes in relation to harvest and natural mortality.

  • 35.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Sjöberg, Kjell
    SLU.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Experimental evidence for density-dependent breeding success in mallards2005Konferansepaper (Fagfellevurdert)
    Abstract [en]

    It is unresolved to what extent waterfowl populations are regulated by density-dependent pro cesses. By doing a 2-year crossover perturbation exper iment on ten oligotrophic boreal lakes we addressed the hypothesis that breeding output is density depen dent. Wing-clipped mallard (Anas platyrhynchos) hens were introduced with their own brood and then moni tored for 24 days. Predicted responses were that per capita duckling and hen survival would be lower in high-density than in low-density treatments. Survival was evaluated by model fitting in program MARK. Density, year, and lake were used as main effects, while day after introduction, a weather harshness index, and presence of hens were covariates. Daily survival in ducklings was lower in the high-density treatment, but this effect was year dependent. The highest-ranking model for duckling survival also included a positive effect of duckling age and presence of hens, and a nega tive effect of harsh weather. Density did not affect female survival although there was a prominent year effect. The highest-ranking model for female survival also included negative effects of day after introduction and harsh weather. This is the first study to report den sity-dependent survival in experimentally introduced ducklings in a natural setting. Implications for population dynamics and management of harvested populations are far-reaching if such regulation occurs in some years, but not in others.

  • 36.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Sjöberg, Kjell
    SLU.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Food limits survival in breeding mallards2003Inngår i: Integrating wildlife with people, 10th International Perdix Symposium, Braga, Portugal, September 1st-6th 2003: abstracts and contributing authors, Braga: International Union of Game Biologists , 2003Konferansepaper (Fagfellevurdert)
  • 37.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Sjöberg, Kjell
    SLU.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Food limits survival of breeding boreal mallards Anas platyrhynchos2003Konferansepaper (Fagfellevurdert)
    Abstract [en]

    During the breeding period dabbling ducks (Anas sp.), and especially newly hatched ducklings, face heavy mortality. The reasons are not clear, but suggested factors contributing are scarce food, predation, chilling and disease. We highlighted the question why many of the boreal lakes in Scandinavia are without breeding ducks and why mortality is considerable during brood period. In an experimental study in 2002 we hypothesized food being a major factor deciding duck survival during breeding. One wing-clipped hen mallard with her own newly hatched brood (10 ducklings) was introduced onto each of 10 lakes. Food was added ad libitum at 5 of these lakes (experimental lakes), whereas the other five lakes (controls) did not get any extra food added. Survival of hens, broods as well as each individual duckling was monitored regularly until 24 days after introduction. At all three levels (i.e. duckling, brood and adult), survival was significantly higher on lakes with food added than on control lakes, although the difference was most pronounced on the duckling level. Direct consequences (i.e. dying from starvation) as well as indirect (e.g. undernourished individuals being more easily taken by predators) may both explain this pattern. Our results clearly show that food is a major limiting factor on mallard survival in this environment. Also, our results may explain why many boreal lakes in Scandinavia do not have any breeding waterfowl at all. It seems likely that such lakes are too poor to raise broods and even to sustain adults.

  • 38.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Waldenström, Jonas
    Section for Zoonotic Ecology and Epidemiology, School of Natural Sciences, Linnaeus University, Kalmar.
    Trends in body mass of ducks over time: the hypotheses in Guillemain et al. revisited2011Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, nr 3, 338-340 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 39.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Latorre-Margalef, Neus
    Hobson, Keith A
    Van Wilgenburg, Steven L
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Olsen, Björn
    Fouchier, R A M
    Waldenström, Jonas
    Within-season trends in natal origin, body size, and influenza A virus subtypes in migrating Mallards2012Konferansepaper (Fagfellevurdert)
  • 40.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Latorre-Margalef, Neus
    Hobson, Keith H
    Van Wilgenburg, Steven L
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Olsen, Björn
    Fouchier, R A M
    Waldenström, Jonas
    Within-season trends in natal origin, body size, and influenza A virus subtypes in migrating Mallards2012Konferansepaper (Fagfellevurdert)
  • 41.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Latorre-Margalef, Neus
    Munster, Vincent
    Wallensten, Anders
    Fouchier, Ron
    Osterhaus, Albert
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Olsen, Björn
    Waldenström, Jonas
    Are body mass and staging time in Mallards (Anas platyrhynchos) affected by infection of influenza A?2007Konferansepaper (Fagfellevurdert)
  • 42.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Ottvall, Richard
    Vadare i Vattenriket – matbrist?2012Konferansepaper (Annet vitenskapelig)
  • 43.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Sjöberg, Kjell
    SLU.
    Elmberg, Johan
    Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH). Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Does climate change affect the breeding success of Mallards Anas platyrynchos?2007Konferansepaper (Fagfellevurdert)
  • 44.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Waldenström, Jonas
    Högskolan i Kalmar.
    Influenza A and sub-lethal effects in mallards at Ottenby, southern Sweden2007Konferansepaper (Fagfellevurdert)
  • 45.
    Gunnarsson, Gunnar
    et al.
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man and Biosphere Health (MABH).
    Waldenström, Jonas
    Section for Zoonotic Ecology and Epidemiology, School of Natural Sciences, Linnaeus University.
    Fransson, Thord
    Bird Ringing Centre, Department of Vertebrate Zoology, Swedish Museum of Natural History, Stockholm.
    Improved mallard survival in Northern Europe over the past forty years2011Inngår i: Abstracts from “Nordic Waterbirds in a warming world”: Öster Malma 24-28 Oct 2011, 2011, 12- s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Vital rates are the cornerstones affecting population dynamics, and are necessary to estimate in order to judge population viability. Knowledge about vital rates and their changes over time is especially important for hunted species, for example to be able to determine sustainable harvest levels. We estimated annual age and sex specific survival rates of the most common waterfowl game in Europe, i.e. the Mallard (Anas platyrhynchos), and studied possible links between survival and hunting pressure, weather (winter harshness) and migration behaviour. Ringing data, covering more than forty years (1964-1982 [called ‘yearly period’] and 2002-2008 [called ‘late period’]), were collected in one stationary duck trap located at Ottenby, south-east Sweden, and mark-recovery data were analysed with a theoretic-information approach using program MARK. In total 10,490 Mallards were marked, i.e. 6,409 in the early period and 4,081 in the late, of which 13.3% (early period) and 4.7% (late period) were recovered dead (mostly hunting; >92%). Within each time period, the survival of Mallards was not dependent on age, sex and year. However, when the different time periods were compared, annual survival was lower in the early period (0.58–0.63) compared to the late (0.69–0.71). There are several possible explanations why survival has improved. Although winter harshness did not directly correlate to survival in the modelling analyses, relationships may be more intricate than as it first appears. Firstly, data show that Mallards in the late period have better body condition (body mass) than in the early period, which may have several explanations, including climate aspects. Secondly, data suggest that the Mallard has shortened its migratory route when time periods are contrasted, with wintering areas further to the north in the late period. Again milder winters may have contributed to this pattern as migrating distances for female Mallards were correlated with winter harshness data. As a consequence, this could potentially also affect survival since migration is costly. Finally, although it is hard to quantify, hunting pressure may also have played a role since it seems to be lower in the late period compared to the early.

  • 46.
    Hansson, Lars-Anders
    et al.
    Lund University.
    Ekvall, Mattias K.
    Lund University.
    Ekvall, Mikael T.
    Lund University.
    Ahlgren, Johan
    Lund University.
    Sidemo Holm, William
    Lund University.
    Dessborn, Lisa
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap. Högskolan Kristianstad, Forskningsmiljön Man & Biosphere Health (MABH).
    Brönmark, Christer
    Lund University.
    Experimental evidence for a mismatch between insect emergence and waterfowl hatching under increased spring temperatures2014Inngår i: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 5, nr 9, 120- s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    By combining a large-scale experimental assessment on timing of insect emergence with longtermmonitoring of waterfowl hatching date, we here show that insect emergence is mainly driven bytemperature, whereas there is only a weak effect of increasing spring temperatures on inter-annualvariability in observations of waterfowl chicks. Hence, a change in timing of the mass-emergence of insectsfrom lakes and wetlands, which is the crucial food source for waterfowl chicks, will likely result in aconsumer/resource mismatch in a future climate change perspective. Specifically, we experimentally showthat a moderate increase in temperature of 38C above ambient, expected to occur within 25–75 years, leadsto a considerably (2 weeks) earlier, and more pronounced, peak in insect emergence (Chironomus sp).Moreover, by utilizing long-term Citizen Science databases, ranging over several decades, we also showthat common waterfowl species are unable to significantly adjust their reproduction to fit futuretemperature increase. Hence, based on our data we predict a future mismatch between insect emergenceand waterfowl species basing their reproduction on temperature. This will have a profound impact onreproductive success and population dynamics of many aquatic birds, as well as on freshwaterbiodiversity.

  • 47. Hedenas, Henrik
    et al.
    Carlsson, Bengt A.
    Emanuelsson, Urban
    Swedish Biodiversity Centre, Uppsala.
    Headley, Alistair D.
    Jonasson, Christer
    Svensson, Brita M.
    Callaghan, Terry V.
    Changes Versus Homeostasis in Alpine and Sub-Alpine Vegetation Over Three Decades in the Sub-Arctic2012Inngår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, 187-196 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Plant species distributions are expected to shift and diversity is expected to decline as a result of global climate change, particularly in the Arctic where climate warming is amplified. We have recorded the changes in richness and abundance of vascular plants at Abisko, sub-Arctic Sweden, by re-sampling five studies consisting of seven datasets; one in the mountain birch forest and six at open sites. The oldest study was initiated in 1977–1979 and the latest in 1992. Total species number increased at all sites except for the birch forest site where richness decreased. We found no general pattern in how composition of vascular plants has changed over time. Three species, Calamagrostis lapponica, Carex vaginata and Salix reticulata, showed an overall increase in cover/frequency, while two Equisetum taxa decreased. Instead, we showed that the magnitude and direction of changes in species richness and composition differ among sites.

  • 48.
    Hettyey, Attila
    et al.
    Ungern.
    Laurila, Anssi
    Uppsala University.
    Herczeg, Gábor
    Ungern.
    Jönsson, K. Ingemar
    Lund University.
    Kovács, Tibor
    Ungern.
    Merilä, Juha
    Finland.
    Does testis weight decline towards the Subarctic?: a case study on the common frog, Rana temporaria2005Inngår i: Die Naturwissenschaften, ISSN 0028-1042, E-ISSN 1432-1904, Vol. 92, nr 4, 188-192 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Interpopulation comparisons of variation in resource availability and in allocation patterns along altitudinal and latitudinal gradients allow insights into the mechanisms shaping the life history of animals. Patterns of between-population differences in female life history traits have been studied intensively across a wide range of taxa, but similar investigations in males have remained scarce. To study if testis weight-a measure of reproductive investment-varies on a geographical scale in anurans, we focussed on the variation in relative testis weight (RelTW) and asymmetry in 22 populations of the common frog Rana temporaria along a 1,600-km latitudinal transect across the Scandinavian peninsula. We found that RelTW decreased towards the north. Body mass and body length both had independent positive effects on testes mass. We found evidence for directional asymmetry (DA) in testis weight with the right testis being larger than the left. The level of DA in testis weight was not related to latitude, but both body mass and testes mass had independent positive effects on asymmetry. We discuss the northwards decrease in RelTW in terms of a decreased reproductive investment as a possible consequence of harsher environmental conditions, and perhaps also, weaker sexual selection in the north than in the south.

  • 49.
    Hladyz, Sally
    et al.
    University College Cork, Department of Zoology.
    Åsbjörnsson, Kajsa
    University College Cork, Department of Zoology.
    Chauvet, Eric
    Université de Toulouse.
    Dobson, Michael
    Manchester Metropolitan University.
    Elosegi, Arturo
    University of the Basque Country, Bilbao.
    Ferreira, Verónica
    University of Coimbra.
    Fleituch, Tadeusz
    Polish Academy of Sciences, Kraków.
    Gessner, Mark O.
    Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum.
    Giller, Paul S.
    University College Cork, Department of Zoology.
    Gulis, Vladislav
    Department of Life Sciences, University of Coimbra.
    Hutton, Stephen. A.
    University College Cork, Department of Zoology.
    Lacoursière, Jean O.
    Högskolan Kristianstad, Sektionen för lärande och miljö.
    Lamothe, Sylvain
    Université de Toulouse.
    Lecerf, Antoine
    Université de Toulouse.
    Malmqvist, Björn
    Umeå University.
    McKie, Brendan G.
    Umeå University.
    Nistorescu, Marius
    University of Bucharest.
    Preda, Elena
    University of Bucharest.
    Riipinen, Miira P.
    Manchester Metropolitan University.
    Risnoveanu, Geta
    University of Bucharest.
    Schindler, Markus
    Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum.
    Tiegs, Scott D.
    Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum.
    Vought, Lena B. M.
    Högskolan Kristianstad, Sektionen för lärande och miljö.
    Woodward, Guy
    University College Cork.
    Stream ecosystem functioning in an agricultural landscape: the importance of terrestrial-aquatic linkages2011Inngår i: Ecosystems in a human-modified landscape: a European perspective / [ed] Guy Woodward, San Diego: Academic Press, 2011, Vol. 44, 211-276 s.Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The loss of native riparian vegetation and its replacement with non-native species or grazing land for agriculture is a worldwide phenomenon, but one that is prevalent in Europe, reflecting the heavily-modified nature of the continent's landscape. The consequences of these riparian alterations for freshwater ecosystems remain largely unknown, largely because bioassessment has traditionally focused on the impacts of organic pollution on community structure. We addressed the need for a broader perspective, which encompasses changes at the catchment scale, by comparing ecosystem processes in woodland reference sites with those with altered riparian zones. We assessed a range of riparian modifications, including clearance for pasture and replacement of woodland with a range of low diversity plantations, in 100 streams to obtain a continental-scale perspective of the major types of alterations across Europe. Subsequently, we focused on pasture streams, as an especially prevalent widespread riparian alteration, by characterising their structural (e.g. invertebrate and fish communities) and functional (e.g. litter decomposition, algal production, herbivory) attributes in a country (Ireland) dominated by this type of landscape modification, via field and laboratory experiments. We found that microbes became increasingly important as agents of decomposition relative to macrofauna (invertebrates) in impacted sites in general and in pasture streams in particular. Resource quality of grass litter (e.g., carbon : nutrient ratios, lignin and cellulose content) was a key driver of decomposition rates in pasture streams. These systems also relied more heavily on autochthonous algal production than was the case in woodland streams, which were more detrital based. These findings suggest that these pasture streams might be fundamentally different from their native, ancestral woodland state, with a shift towards greater reliance on autochthonous-based processes. This could have a destabilizing effect on the dynamics of the food web relative to the slower, detrital-based pathways that dominate in woodland streams.

  • 50.
    Holopainen, Sari
    et al.
    Finland.
    Arzel, Céline
    Finland.
    Dessborn, Lisa
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Gunnarsson, Gunnar
    Högskolan Kristianstad, Sektionen för lärande och miljö, Avdelningen för Naturvetenskap.
    Nummi, Petri
    Finland.
    Pöysä, Hannu
    Finland.
    Sjöberg, Kjell
    SLU.
    Habitat use in ducks breeding in boreal freshwater wetlands: a review2015Inngår i: European Journal of Wildlife Research, ISSN 1612-4642, E-ISSN 1439-0574, Vol. 61, nr 3, 339-363 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Breeding habitats strongly influence duck reproduction and survival. The boreal biome harbours a large share of the worlds wetlands, which are important breeding sites for several duck species. Based on 98 studies in the peer-reviewed literature, we here synthesize and evaluate which habitat characteristics affect habitat use and reproduction of ducks breeding in boreal freshwater wetlands with respect to (1) species and guild (dabbling, diving and piscivorous ducks) and (2) breeding cycle stage (settling by pairs, nesting and brood rearing). We consider the following aspects related to habitat: wetland morphology and spatial aggregation, water characteristics, habitat structure and vegetation, and biotic interactions. Most of the peer-reviewed studies of duck habitat use in boreal wetlands are from North America and Fennoscandia, while nearly half of the boreal area lacks such studies. Few species dominate research thus far while several others have not been studied at all. Nest site use and success are mainly related to predator avoidance. Food resources and habitat structure are the key characteristics affecting habitat use by duck pairs and broods as well as breeding success, although there are differences between duck guilds. Among the commonly studied variables, there is little evidence that water characteristics affect duck habitat use or survival. The most notable knowledge gaps are found in the effects of anthropogenic activities on habitat use and breeding success of ducks. Because boreal breeding environments are increasingly affected by human activities, we underline the need for future studies combining climate variation with natural and anthropogenic disturbances.

12 1 - 50 of 92
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf