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  • 51. 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)2011In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, no 6, p. 705-716Article in journal (Refereed)
    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.

  • 52.
    Cardegård, Fanny
    Kristianstad University, Faculty of Natural Science.
    Alléer i Östergötlands län: alléers utbredning och förändring mellan 1868-1877 och idag2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Avenues are a landscape element that consist of both nature and culture and that’s been planted by man for various reason. The Swedish avenues reduces because of that the Trafikverket and the Riksantikvarieämbetet wishes to develop a national basis for avenues. In Östergötland there is no compilation of avenues in historical time because of that the purpose of the study is to examine avenues spread and continuity in Östergötland from 1868 until today. Avenues has the greatest occurence in the flat country. Avenues belonging to manor or factory had changed least from the period 1868-1877 until today which is probably due to avenues belonging to manor or factory already was common under the period 1868-1877. Approach avenues leading to farms has increased in the districts since 1868-1877 which can be linked to the agriculture shiftreform that changed the landscape in the late 19th century and gave rise to avenue plantings in the county. Today’sk avenues are avenues witch mixed tree species uppermost occurring.

  • 53.
    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 PDR2005In: Biological Invasions, ISSN 1387-3547, E-ISSN 1573-1464, Vol. 7, no 2, p. 233-241Article in journal (Refereed)
    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.

  • 54.
    Champagnon, Jocelyn
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, Arles.
    Crochet, P. A.
    Centre d'Ecologie Fonctionnelle et Evolutive, UMR 5175 – CNRS, Montpellier.
    Kreisinger, J.
    Department of Zoology, Faculty of Science, Charles University in Prague.
    Čížková, D.
    Department of Population Biology, Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Brno.
    Gauthier-Clerc, M.
    Centre de Recherche de la Tour du Valat, Arles.
    Massez, G.
    Les Marais du Vigueirat, Arles.
    Söderquist, Pär
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Albrecht, T.
    Department of Zoology, Faculty of Science, Charles University in Prague.
    Guillemain, M.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, Arles.
    Assessing the genetic impact of massive restocking on wild mallard2013In: Animal Conservation, ISSN 1367-9430, E-ISSN 1469-1795, Vol. 16, no 3, p. 295-305Article in journal (Refereed)
    Abstract [en]

    Captive-bred mallards Anas platyrhynchos have been released for hunting purposes at a very large scale in Europe since the mid-1970s. In spite of a potential genetic impact, the actual contribution of restocked mallards to the genome of the target population has received little attention. The genetic structure of modern wild mallards in the Camargue, Southern France, was assessed from two samples: one originating from shot birds in hunting bags and one from presumed wild ducks captured alive in a hunting-free reserve. Reference samples originated from five mallard farms, as well as from museum samples collected before the mid-1970s (i.e. before massive mallard releases started). Our results revealed that the genetic signature of wild wintering mallards has not changed significantly because museum and presumed wild samples from the Camargue hunting-free nature reserve were genetically similar, and clearly differentiated from the farm mallards. This suggests that mallard releases in the Camargue or elsewhere in France, although massive, have not actually translated into complete admixture of wild and captive genomes, most likely due to low survival of released birds once in the wild. Nevertheless, although genetic introgression of the wild population by captive-bred was contained, we found significant rates of hybridization between wild and captive-bred mallards in modern samples. This result suggests that long-term releases of captive-bred mallards, if carried on at such large scale, could compromise irreversibly the genetic structure and composition of European mallards. This work contributes to fill in the gap on the monitoring of the genetic consequences of large-scale game releases for exploitation.

  • 55.
    Champagnon, Jocelyn
    et al.
    Office National de la Chasse et de la Faune Sauvage – CNERA Avifaune Migratrice, Le Sambuc, Arles.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Guillemain, Matthieu
    Office National de la Chasse et de la Faune Sauvage – CNERA Avifaune Migratrice, Le Sambuc, Arles.
    Gauthier-Clerc, Michel
    Centre de Recherche de la Tour du Valat, Le Sambuc, Arles.
    Lebreton, Jean-Dominique
    Centre d’Ecologie Fonctionnelle et Evolutive UMR 5175 - CNRS, Montpellier.
    Conspecifics can be aliens too: a review of effects of restocking practices in vertebrates2012In: Journal for Nature Conservation, ISSN 1617-1381, E-ISSN 1618-1093, Vol. 20, no 4, p. 231-241Article in journal (Refereed)
    Abstract [en]

    We review the indexed scientific literature (233 papers) dealing with ‘restocking’ of vertebrates, i.e. reinforcement of wild populations by release of individuals of the same species. We found evidence that restocking may have desired beneficial effects such as: increased genetic diversity and mitigation of Allee effects in small populations; increased size or even salvation of threatened populations; increased harvest opportunities; and, redirection of harvest pressure from wild to captive-bred individuals. However, restocking may also have negative effects like changes in behaviour, morphology, and demography in recipient populations, as well as enhancement of pathogen spread. Negative genetic effects on recipient populations include homogenisation, introduction of non-native genes, and loss of local adaptation. Research thus far is strongly biased towards birds and mammals, and geographically to Europe and North America. Restocking for conservation purposes has been studied more than that for harvest management, while the latter may be of far greater importance in terms of number of released individuals. Demographic and genetic effects have been studied more than effects on behaviour, which in turn have received more attention than effects on morphology and pathogen spread. There is a general tendency for research on restocking to be fragmented taxonomically and by biological sub-disciplines. Our review demonstrates that restocking practices may and do cause significant disruptions of natural patterns in wild recipient populations. It also highlights the diversity, frequency and extent of these activities, leading us to argue that restocking is an emerging conservation and ecosystem resilience issue of global significance. Based on this review we outline monitoring and research needs for the future. We also provide guidelines to practitioners in conservation, game management, fisheries, epidemiology and other fields involved in restocking of vertebrates, who are likely to benefit from merging their perspectives and adopting a more cross-taxonomical and interdisciplinary attitude when laying out future agendas for evaluation and policy-making in this field.

  • 56.
    Champagnon, Jocelyn
    et al.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, Arles.
    Guillemain, Matthieu
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, Arles.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Folkesson, Karin
    Kristianstad University, School of Health and Society.
    Gauthier-Clerc, Michel
    Centre de Recherche de la Tour du Valat, Le Sambuc, Arles.
    Changes in Mallard Anas platyrhynchos bill morphology after 30 years of supplemental stocking2010In: Bird Study, ISSN 0006-3657, E-ISSN 1944-6705, Vol. 57, no 3, p. 344-351Article in journal (Refereed)
    Abstract [en]

    Capsule Massive releases of captive-reared Mallard for hunting purposes have been practiced for 30 years. During this period the number of lamellae per centimetre of bill length in wild Mallard populations has decreased. Aims Every year since the 1970s, several million captive Mallard have been released in Europe. This may lead to a spread of unnatural phenotypes into the wild. Nevertheless, the consequences of such introductions have not been examined. Methods Two widespread and common migratory ducks were studied: Mallard Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which stocking programmes occur, and Teal served as a control. In a 'before-after' design, we compared duck bill lamellar density over the last 30 years. Results Lamellar density in Mallard, but not Teal, decreased. The observed 10% decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. Conclusions We hypothesize that the change in bill morphology was because of the propagation of captive Mallard into the wild: captive Mallard eat mainly large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small prey in wild ducks.

  • 57.
    Champagnon, Jocelyn
    et al.
    French Hunting and Wildlife Agency, Arles, France.
    Guillemain, Matthieu
    French Hunting and Wildlife Agency, Arles, France.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Folkesson, Karin
    Kristianstad University, School of Education and Environment.
    Gauthier-Clerc, Michel
    Tour du Valat Research Center, Arles.
    Do stocking programs result in maladapted populations?: mallard bill morphology after 30 years of massive releases2011In: Abstracts: Joint meeting of the 11th North American Crane Workshop and the 34th Annual Meeting of The Waterbird Society, Grand Island, Nebraska, USA, March 13-16, 2011, 2011, p. 31-Conference paper (Other academic)
    Abstract [en]

    Every year since the 1970s, several million captive Mallard have been released in Europe for hunting purposes. This may lead to a spread of unnatural phenotypes into the wild. Two widespread and common migratory ducks were studied: Mallard    Anas platyrhynchos and Teal A. crecca. Mallard is the only duck species for which large-scale stocking programs occur in the region, and Teal hence serves as a control. In a « before-after » design, we compared duck bill lamellar density over the last thirty years. Lamellar density in Mallard, but not Teal, decreased. The observed 10 % decrease occurred in the first (proximate) centimetre of the bill, the most crucial in terms of food filtration. We hypothesize the observed change in bill morphology was due to the propagation of captive Mallard into the wild: captive Mallard mainly eat large items, relaxing the natural selection pressure maintaining high lamellar density for sieving small preys in wild ducks.

  • 58.
    Champagnon, Jocelyn
    et al.
    French Hunting and Wildlife Agency, Le Sambuc, Arles.
    Guillemain, Matthieu
    French Hunting and Wildlife Agency, Le Sambuc, Arles.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Massec, Grégoire
    Marais du Vigueirat, Mas Thibert, Arles.
    Gauthier-Clerc, Michel
    Tour du Valat Research Center, Le Sambuc, Arles.
    Survival probability and morphological adaptation of captive-reared Mallard Anasplatyrhynchos after release into the wild2011In: Abstracts: Joint meeting of the Association of Field Ornithologists, the Cooper Ornithological Society, and the Wilson Ornithological Society, Kearny, Nebraska, USA, March 9-12, 2011, 2011, p. 16-Conference paper (Other academic)
    Abstract [en]

    Captive-reared animals released as part of reinforcement programmes are considered less likely to survive than their wild conspecifics. One of the possible causes for this is reduced digestion efficiency. We studied adaptation of the digestive system in Mallard, a species with high adaptability to its environment. Body condition and digestive organs were compared between three groups: captive-reared Mallards remaining in a game farm, captive-reared Mallards released into the wild as juveniles and wild Mallards. We also assessed difference in diet between released birds and wild birds, and conducted a one-year survival analysis of captive-reared birds released in a hunting-free area. Released Mallards had a smaller gizzard than wild birds, but there was no difference between captive-reared and wild Mallards in the size of others organs in the gastro-intestinal tract. Body condition of captive-reared Mallards was poorer than wild ones, and this was only partially improved after release. Survival probability of captive-reared Mallards was low, compared to documented survival of wild Mallards. In particular, high mortality occurred when additional food provisioning was stopped and during harsh winter periods. We argue that in spite of a viable digestive system, pre-release conditions experienced by captivereared ducks impeded restocking success. In the context of massive releases of this species for hunting purposes (several million birds per year in Europe), low survival due to a combination of high hunting pressure and poor condition could limit the number of farmed birds surviving to breed and thus limit introgression of "captive genes" into the wild population.

  • 59.
    Champagnon, Jocelyn
    et al.
    Frankrike.
    Guillemain, Matthieu
    Frankrike.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Massez, Grégoire
    Frankrike.
    Cavallo, Francois
    Frankrike.
    Gauthier-Clerc, Michel
    Frankrike.
    Low survival after release into the wild: assessing “the burden of captivity” on Mallard physiology and behaviour2012In: European Journal of Wildlife Research, ISSN 1612-4642, E-ISSN 1439-0574, Vol. 58, no 1, p. 255-267Article in journal (Refereed)
    Abstract [en]

    Captive-reared animals used in reinforcement programs are generally less likely to survive than wild conspecifics. Digestion efficiency and naive behaviour are two likely reasons for this pattern. The Mallard is a species with high adaptability to its environment and in which massive reinforcement programs are carried out. We studied physiological and behavioural factors potentially affecting body condition and survival of captive-reared Mallards after being released. Digestive system morphology and an index of body condition were compared among three groups: captive-reared birds remaining in a farm (control), captive-reared birds released into the wild as juveniles (released) and wild-born birds (wild). We also compared behaviour and diet of released vs. wild Mallards. Finally, we conducted a 1-year survival analysis of captive-reared birds after release in a hunting-free area. Gizzard weight was lower in control Mallards, but the size of other organs did not differ between controls and wild birds. The difference in gizzard weight between released and wild birds disappeared after some time in the wild. Diet analyses suggest that released Mallards show a greater preference than wild for anthropogenic food (waste grain, bait). Despite similar time-budgets, released Mallards never attained the body condition of wild birds. As a consequence, survival probability in released Mallards was low, especially when food provisioning was stopped and during harsh winter periods. We argue that the low survival of released Mallards likely has a physiological rather than a behavioural (foraging) origin. In any case, extremely few released birds live long enough to potentially enter the breeding population, even without hunting. In the context of massive releases presently carried out for hunting purposes, our study indicates a low likelihood for genetic introgression by captive-reared birds into the wild population.

  • 60.
    Champagnon, Jocelyn
    et al.
    Frankrike.
    Guillemain, Matthieu
    Frankrike.
    Gauthier-Clerc, Michel
    Frankrike.
    Lebreton, Jean-Dominique
    Frankrike.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Consequences of massive bird releases for hunting purposes: mallard Anas platyrhynchos in the Camargue, Southern France2009In: Wildfowl, ISSN 0954-6324, E-ISSN 2052-6458, no Special issue 2, p. 184-191Article in journal (Refereed)
    Abstract [en]

    The release of captive-reared fish and game animals into the wild is a common management practice in Europe and North America. In Europe, millions of reared birds are released each year yet the consequences of these release programmes have received little attention. This paper describes the massive introduction of Mallard Anas platyrhynchos, a native migrant species released into the wild to increase the size of hunted populations. It provides the rationale for current and forthcoming experiments aimed at determining the effects of the augmentation of Mallard stocks on wild population genotype and survival rates.

  • 61.
    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.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment 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.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment 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 project2016In: Large-scale ecology: model systems to global perspectives / [ed] Alex J. Dumbrell, Rebecca L. Kordas; Woodward, Guy, London: Academic Press , 2016, Vol. 55, p. 99-182Chapter in book (Refereed)
    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.

  • 62.
    Cifuentes de Gramajo, Luisa
    Kristianstad University, School of Education and Environment.
    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 credits / 15 HE creditsStudent thesis
    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.

  • 63. Clausen, P.
    et al.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Fox, A.
    Heldbjerg, H.
    Lindström, Å.
    Pöysä, Hannu
    Mallard declines in Western Europe: evidence of true population declines or just short-stopping in milder winters?2009In: Abstracts, 2nd Pan-European Duck Symposium, 2009, p. 49-Conference paper (Refereed)
  • 64.
    Collin, Betty
    Kristianstad University, School of Education and Environment.
    Characterization and persistence of potential human pathogenic vibrios in aquatic environments2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Vibrio spp., natural inhabitants of aquatic environments, are one of the most common causes of bacterial gastroenteritis in the world, being spread to humans via the ingestion of seafood, contaminated drinking water or exposure to seawater. The majority of Vibrio spp. are avirulent, but certain strains may sporadically be human pathogenic. Vibrio cholerae may cause cholera and fatal wound infections, Vibrio parahaemolyticus may cause gastroenteritis and Vibrio vulnificus may cause wound infections and sepsis. To expand current knowledge of the occurrence, ecological niche and persistence of potential human pathogenic Vibrio spp. in aquatic environments, occurrence and laboratory studies were performed. The seasonal variation of Vibrio spp. in clams and mussels from Mozambique and Sweden were studied, with isolated strains characterized and compared with those isolated from water samples collected in India. Results showed that the numbers of Vibrio spp. in Mozambican clams peaked during the warmer rainy season and that the dominating species was V. parahaemolyticus. Biochemical fingerprinting and virulence screened by PCR revealed a high similarity among strains from the different aquatic environments. However, isolate functional hemolytic analyses and antibiotic resistance patterns differed between strains; Swedish and Indian strains were less sensitive to the tested antibiotics and had a lower hemolytic capacity than those from Mozambique. Molecular analysis of bacterial DNA from Swedish mussels showed the presence of the three Vibrio spp. most commonly linked with human illness, as well as their associated virulence genes. The strains isolated from marine and clinical environments were equally and highly harmful to the tested eukaryotic cells. The persistence of clinical V. cholerae in aquatic environments was investigated in vivo. Strains were exposed to mussels, with bacterial uptake and elimination then examined. The mussels were able to avoid the most potent strain by complete closure of shells. The less potent strain was accumulated in mussel tissue in low levels and one marine control strain to a higher degree. Mussels eliminated the pathogenic strain less efficiently than they did the marine strain. One clinical and one marine strain were then exposed to 4°C for 21 days, with the temperature then increased to 20°C. The clinical strain was more prone to lose culturability than the marine strain at 4°C, the former performed significantly better in regaining culturability after the temperature up-shift. Subsequently, the persistence of the clinical strain in natural bottom sediment, incubating as above, was studied and results showed a similar decrease in culturable numbers in the sediment as in the water. As the clinical V. cholerae strains did not carry any of the standard set of virulence genes, the ability to change from non-culturable to culturable may be of great importance to strain pathogenicity. The results also show that natural bottom sediment may be a potential reservoir of human pathogenic Vibrio spp.

  • 65.
    Collin, Betty
    et al.
    Kristianstad University, School of Education and Environment.
    Hernroth, Bodil
    Kristianstad University, School of Health and Society.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment.
    The importance of marine sediments as a reservoir for human pathogenic Vibrio cholerae in cold water conditionsArticle in journal (Refereed)
  • 66.
    Collin, Betty
    et al.
    Kristianstad University, School of Education and Environment.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment.
    Occurrence and potential pathogenesis of Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus on the South Coast of Sweden2011In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 78, no 2, p. 306-313Article in journal (Refereed)
    Abstract [en]

    During the summer of 2006, several wound infections - of which three were fatal caused by Vibrio cholerae were reported from patients who had been exposed to water from the Baltic Sea. Before these reports, we initiated a sampling project investigating the occurrence of potential human pathogenic V. cholerae, Vibrio vulnificus and Vibrio parahaemolyticus in The Sound between Sweden and Denmark. The Blue mussel (Mytilus edulis) was used as an indicator to follow the occurrence of vibrios over time. Molecular analyses showed high frequencies of the most potent human pathogenic Vibrio spp.; 53% of mussel samples were positive for V. cholerae (although none were positive for the cholera toxin gene), 63% for V. vulnificus and 79% for V. parahaemolyticus (of which 47% were tdh(+) and/or trh(+)). Viable vibrios were also isolated from the mussel meat and screened for virulence by PCR. The mortality of eukaryotic cells when exposed to bacteria was tested in vivo, with results showing that the Vibrio strains, independent of species and origin, were harmful to the cells. Despite severe infections and several deaths, no report on potential human pathogenic vibrios in this area had been published before this study.

  • 67.
    Collin, Betty
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Ehn Börjesson, Stina-Mina
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Mussagy, Aidate
    Department of Biological Sciences, Eduardo Mondlane University, Maputo, Mozambique.
    Hernroth, Bodil
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Characteristics of potentially pathogenic vibrios from subtropical Mozambique compared with isolates from tropical India and boreal Sweden2013In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 83, no 2, p. 255-264Article in journal (Refereed)
    Abstract [en]

    Reported outbreaks of Vibrio parahaemolyticus have increased worldwide, particularly in regions of high seafood consumption. In Mozambique, seafood constitutes an important food resource and diarrheal diseases are common among its inhabitants. Edible clams were collected in Maputo Bay during both the dry and rainy seasons, with the results showing the number of viable counts of vibrios in clams to peak during the latter. Vibrio parahaemolyticus was the predominant species identified among the isolated strains. Although only one of 109 total strains carried the tdh virulence gene, 69% of isolates showed evidence of hemolytic capacity when subjected to a functional test. Similar virulence patterns and biochemical properties were found in strains isolated from Indian and Swedish marine waters. Antibiotic resistance was, however, more pronounced in strains isolated from these latter two environments.

  • 68.
    Collin, Betty
    et al.
    Kristianstad University, Department of Mathematics and Science.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, Department of Mathematics and Science.
    Hernroth, Bodil
    he Royal Swedish Academy of Sciences, Kristineberg, Fiskebäckskil.
    Faecal contaminants in edible bivalves from Maputo Bay, Mozambique: seasonal distribution, pathogenesis and antibiotic resistance2008In: Open Nutrition Journal, ISSN 1874-2882, Vol. 2, p. 86-93Article in journal (Refereed)
    Abstract [en]

    In Maputo, Mozambique marine bivalves considerably contribute to the diet of the population. This study aimed to investigate seasonal distribution of Escherichia coli and Salmonella in clams from Maputo Bay, and examine their pathogenesis and antibiotic-resistant patterns. Standard multiple tube method revealed that the concentration of coliforms in all samples exceeded the limit for direct consumption, according to EU standards. Thirty-eight percent of the samples contained >60,000 MPN per 100 gram flesh. The occurrence of E. coli did not differ significantly due to season, while Salmonella was present in 100% of the samples during the rainy period and only in 30% during the dry. Multiplex polymerase chain reaction showed that 45% of E. coli isolates were positive for the virulent indicator gene fimA. The Salmonella isolates were identified as S. enterica serovar Typhimurium. Among other isolated coliformic Enterobacteriaceae, Shigella sp. (specie), which in low doses can cause severe gastrointestinal infections, was identified. Antimicrobial susceptibility, recorded by the disk diffusion method, showed resistance to the most commonly used antibiotics. This high levels of faecal contaminants in the clams points out the need for risk assessment and sanitary improvements.

  • 69.
    Collin, Betty
    et al.
    Kristianstad University, School of Education and Environment.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment.
    Lindmark, Barbro
    Department of Molecular Biology, Umeå University.
    Pal, Amit
    National Institute of Cholera and Enteric Diseases, Kolkata, India.
    Wai, Sun N.
    Department of Molecular Biology, Umeå University.
    Hernroth, Bodil
    Kristianstad University, School of Health and Society.
    The origin of Vibrio cholerae influences uptake and persistence in the blue mussel Mytilus edulis2012In: Journal of Shellfish Research, ISSN 0730-8000, E-ISSN 1943-6319, Vol. 31, no 1, p. 87-92Article in journal (Refereed)
    Abstract [en]

    Vibrio cholerae may cause diarrheal diseases and wound infections, both of which have the potential to be fatal. Transmission to humans is often linked to consumption of contaminated shellfish/drinking water or dermal exposure to water (e.g. when swimming). In this study, we investigated whether different isolates of Vibrio cholerae differ in terms of accumulation, persistence, and viability when encountering blue mussels (Mytilus edulis). Mussel uptake and elimination of three different V. cholerae strains were compared: one fatal clinical non-O1/O139 isolate, one highly potent El Tor biotype, and one marine strain isolated from blue mussels. The results showed that the uptake of the marine strain was significantly higher than the clinical strain, but the elimination process of the marine strain was also more efficient. The El Tor strain was not at all ingested by the mussels. In addition, the survival of bacteria when incubated together with M. edulis hemocytes was tested in vitro. The viability of clinical strains was unaffected by the presence of hemocytes, and the marine strains were even more resistant and able to multiply. We conclude that the highly virulent El Tor biotype was not taken up by the mussels and could thereby escape the mussels' elimination process. The potentially fatal non-O1/O139 V. cholerae strain may accumulate in low numbers, but could be very persistent in mussels.

  • 70. Cousins, Sara
    et al.
    Dahlström, Anna
    Emanuelsson, Urban
    Kristianstad University College, School of Teacher Education.
    Eriksson, Ove
    Henningsson, Silvia
    Lennartsson, Tommy
    Lindborg, Regina
    Persson, Inger
    Sjödin, N. Erik
    Stenseke, Marie
    Svensson, Roger
    I nattviolens hage2008In: Olsson, R. (red), Mångfaldsmarker: naturbetesmarker - en värdefull resurs, Uppsala: Centrum för biologisk mångfald , 2008, p. 9-28Chapter in book (Other academic)
    Abstract [sv]

    I en svensk naturbetesmark kan man hitta över 40 växtarter inom en enda kvadratmeter. Det är världsrekord. En stor del av de arter som finns i betesmarkerna förekommer inte i andra naturtyper. Idag återstår inte mer än en tiondel av den areal naturbetesmarker som fanns i Sverige för drygt 100 år sedan. Igenväxningen hotar inte bara en lång rad arter. Också stora kulturhistoriska värden och vårt vackra, variationsrika odlingslandskap står på spel. Fortsatt hävd förutsätter att det finns en levande landsbygd med bärkraftiga jordbruksföretag.

  • 71.
    Czernekova, Michaela
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH). Charles University, Prague.
    Janelt, Kamil
    Polen.
    Jönsson, K. Ingemar
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Chajec, Łukasz
    Polen.
    Student, Sebastian
    Polen.
    Poprawa, Izabela
    Polen.
    Ultrastructure and 3D reconstruction of the tun in Richtersius coronifer (Richters, 1903)2016Conference paper (Refereed)
    Abstract [en]

    Anhydrobiosis is one of the types of cryptobiosis that is caused by lack of water (desiccation). Formation of a tun seems to be the most important morphological adaptation for entering anhydrobiotic state. During this process the tardigrade body undergo anterior-posterior contraction that causes relocation of some organs such as the pharyngeal bulb. The tun wall of Richtersius coronifer (Eutardigrada,  Macrobiotidae) was composed of multilayered cuticle and epidermis. The epidermis consisted of the single squamous epithelium whose cells were shrunken whereas  the cuticle was composed of epi-, intra- and procuticle, flocculent coat and trilaminate layer. The storage cells of desiccated specimens filled up free inner space and surrounded the internal organs (ovary, digestive system) that were contracted. All cells of the body underwent shrinking and their metabolism was arrested. The cytoplasm of all cells was electron dense but the basic morphology of cells and organelles did not differ between active and anhydrobiotic animals. The structure and the ultrastructure of the desiccated Richtersius coronifer have been described with light and confocal microscopy as well as transmission and scanning electron microscopy. 3D reconstruction of tun based on the series of semi-thin sections was prepared with IMARIS 8.2 software (Bitplane).

  • 72.
    Czernekova, Michaela
    et al.
    Kristianstad University, Faculty of Natural Science, Research environment Man & Biosphere Health (MABH). Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap. Charles University, Prague.
    Janelt, Kamil
    Poland.
    Student, Sebastian
    Poland.
    Jönsson, K. Ingemar
    Kristianstad University, Faculty of Natural Science, Research environment Man & Biosphere Health (MABH). Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap.
    Poprawa, Izabela
    Poland.
    A comparative ultrastructure study of storage cells in the eutardigrade Richtersius coronifer in the hydrated state and after desiccation and heating stress2018In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 13, no 8Article in journal (Refereed)
    Abstract [en]

    Tardigrades represent an invertebrate phylum with no circulatory or respiratory system.Their body cavity is filled with free storage cells of the coelomocyte-type, which are responsible for important physiological functions. We report a study comparing the ultrastructure of storage cells in anhydrobiotic and hydrated specimens of the eutardigrade Richtersius coronifer. We also analysed the effect of temperature stress on storage cell structure. Firstly, we verified two types of ultrastructurally different storage cells, which differ in cellular organelle complexity, amount and content of reserve material and connection to oogenetic stage. Type I cells were found to differ ultrastructurally depending on the oogenetic stage of the animal. The main function of these cells is energy storage. Storage cells of Type I were also observed in the single male that was found among the analysed specimens. The second cell type, Type II, found only in females, represents young undifferentiated cells, possibly stem cells. The two types of cells also differ with respect to the presence of nucleolar vacuoles,which are related to oogenetic stages and to changes in nucleolic activity during oogenesis. Secondly, this study revealed that storage cells are not ultrastructurally affected by six months of desiccation or by heating following this desiccation period. However, heating of the desiccated animals (tuns) tended to reduce animal survival, indicating that longterm desiccation makes these animals more vulnerable to heat stress. We confirmed the degradative pathways during the rehydration process after desiccation and heat stress. Our study is the first to document two ultrastructurally different types of storage cells in tardigrades and reveals new perspectives for further studies of tardigrade storage cells.

  • 73.
    Czernekova, Michaela
    et al.
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Tjeckien.
    Jönsson, K. Ingemar
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Experimentally induced repeated anhydrobiosis in the Eutardigrade Richtersius coronifer2016In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 11, no 11, article id e0164062Article in journal (Refereed)
    Abstract [en]

    Tardigrades represent one of the main animal groups with anhydrobiotic capacity at any stage of their life cycle. The ability of tardigrades to survive repeated cycles of anhydrobiosis has rarely been studied but is of interest to understand the factors constraining anhydrobiotic survival. The main objective of this study was to investigate the patterns of survival of the eutardigrade Richtersius coronifer under repeated cycles of desiccation, and the potential effect of repeated desiccation on size, shape and number of storage cells. We also analyzed potential change in body size, gut content and frequency of mitotic storage cells. Specimens were kept under non-cultured conditions and desiccated under controlled relative humidity. After each desiccation cycle 10 specimens were selected for analysis of morphometric characteristics and mitosis. The study demonstrates that tardigrades may survive up to 6 repeated desiccations, with declining survival rates with increased numberof desiccations. We found a significantly higher proportion of animals that were unable to contract properly into a tun stage during the desiccation process at the 5th and 6th desiccations. Also total number of storage cells declined at the 5th and 6th desiccations, while no effect on storage cell size was observed. The frequency of mitotic storage cells tended to decline with higher number of desiccation cycles. Our study shows that the number of consecutive cycles of anhydrobiosis that R. coronifer may undergo is limited, with increased inability for tun formation and energetic constraints as possible causal factors.

  • 74.
    Czernekova, Michaela
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH). Charles University, Prague.
    Jönsson, K. Ingemar
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Mitosis in storage cells of the eutardigrade Richtersius coronifer2016In: Zoological Journal of the Linnean Society, ISSN 0024-4082, E-ISSN 1096-3642, Vol. 178, no 4, p. 888-896Article in journal (Refereed)
    Abstract [en]

    Although tardigrades are sometimes reported as eutelic animals, mitosis has been reported in several somatic tissues of adult eutardigrades. The occurrence of cell division in storage cells is particularly interesting in light of the important role that these cells play in the physiology of tardigrades. We present data on the occurrence of mitosis in storage cells of the eutardigrade Richtersius coronifer (Richters, 1903), and analyse mitotic cells in relation to different body characteristics, including egg development stage, moulting, gut content, body length, number and size of oocytes, and shape and size of the storage cells. Mitosis was present in ~20% of all animals, and was more frequent in juveniles than in adults. The proportion of cells with mitosis (‘mitotic index’) was low: 0.76% in juveniles and 1.47% in adults. In juveniles, none of the measured phenotypic characters had significant predictive power for mitosis, whereas in adult animals in moult or in late egg developmental or post-laying stage were more likely to have mitotic storage cells. The association with the later part of the moulting process was particularly strong. The low mitotic index and the strong association with moulting suggests that mitosis in storage cells may be connected with somatic growth rather than cell renewal, and that the purpose of cell division may relate to a need of more cells to support the enlarged body after moulting. However, the specific life cycle of tardigrades, where energy intake and depletion, egg development, and moulting is highly intertwined and synchronized, make conclusions about the functional role of mitosis in storage cells difficult, however, and more studies are needed to reveal the mechanisms inducing mitosis in these interesting cells.

  • 75.
    Czernekova, Michaela
    et al.
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Jönsson, K. Ingemar
    Kristianstad University, Research environment Man & Biosphere Health (MABH). Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Mitosis in storage cells of the eutardigrade Richtersius coronifer2015Conference paper (Refereed)
    Abstract [en]

    Tardigrades are often reported as eutelic animals, characterized by a constant cell number after maturity and growing by cell enlargement rather than by increased cell number. However, mitosis has been reported in some of the somatic tissues of adult eutardigrades, including the storage cells, and are therefore not strictly eutelic. Very few studies have investigated the presence of mitosis in tardigrades, and the occurrence of cell division in storage cells is particularly interesting in light of the important role that these cells may play in the physiology and immunology of tardigrades. We present data on the occurrence of mitosis in storage cells of the eutardigrade Richtersius coronifer and provide an analysis of storage cell mitosis in relation to different body characteristics. Specimens were examined for mitotic cells using in toto staining with aceto-lactic orcein, and the same animals were characterized with respect to egg development stage, number of oocytes, gut content, body size, and shape and size of the storage cells. Mitosis was present in ca. 30% of the animals. A large majority (3/4) of the animals with mitotic cells were found in specimens at moulting or directly after egg laying. Amount of gut content was associated with mitosis, with highest mitosis frequency (ca. 50%) in animals with an empty gut. These results for egg developmental stage (incl. moulting) and gut content are however not independent, since gut content generally decrease towards the end of the reproductive cycle. Other measured body characteristics did not influence the frequency of mitosis. In juveniles, mitotic cells were found in about half of the examined specimens. Our results suggest that proliferation of storage cells in R. coronifer is connected to the general life cycle dynamics, and provide a basis for more in depth analyses of the functional role and dynamics of storage cells in tardigrades.

  • 76.
    Czernekova, Michaela
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH). Tjeckien.
    Jönsson, K. Ingemar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Chajec, Lukasz
    Polen.
    Student, Sebastian
    Polen.
    Poprawa, Izabela
    Polen.
    The structure of the desiccated Richtersius coronifer (Richters, 1903)2017In: Protoplasma, ISSN 0033-183X, E-ISSN 1615-6102, Vol. 254, no 3, p. 1367-1377Article in journal (Refereed)
    Abstract [en]

    Tun formation is an essential morphological adaptation for entering the anhydrobiotic state in tardigrades, but its internal structure has rarely been investigated. We present the structure and ultrastructure of organs and cells in desiccated Richtersius coronifer by transmission and scanning electron microscopy, confocal microscopy, and histochemical methods. A 3D reconstruction of the body organization of the tun stage is also presented. The tun formation during anhydrobiosis of tardigrades is a process of anterior-posterior body contraction, which relocates some organs such as the pharyngeal bulb. The cuticle is composed of epicuticle, intracuticle and procuticle; flocculent coat; and trilaminate layer. Moulting does not seem to restrict the tun formation, as evidenced from tardigrade tuns that were in the process of moulting. The storage cells of desiccated specimens filled up the free inner space and surrounded internal organs, such as the ovary and digestive system, which were contracted. All cells (epidermal cells, storage cells, ovary cells, cells of the digestive system) underwent shrinkage, and their cytoplasm was electron dense. Lipids and polysaccharides dominated among reserve material of storage cells, while the amount of protein was small. The basic morphology of specific cell types and organelles did not differ between active and anhydrobiotic R. coronifer.

  • 77.
    Czernekova, Michaela
    et al.
    Kristianstad University, Faculty of Natural Science, Research environment Man & Biosphere Health (MABH). Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap. Czech republic.
    Jönsson, K. Ingemar
    Kristianstad University, Faculty of Natural Science, Research environment Man & Biosphere Health (MABH). Kristianstad University, Faculty of Natural Science, Avdelningen för miljö- och biovetenskap.
    Hajer, Jaromir
    Czech republic.
    Devetter, Miroslav
    Czech Republic..
    Evaluation of extraction methods for quantitative analysis of tardigrade populations in soil and leaf litter2018In: Pedobiologia, ISSN 0031-4056, E-ISSN 1873-1511, Vol. 70, p. 1-5Article in journal (Refereed)
    Abstract [en]

    Accurate quantitative analysis of soil tardigrades depends on a relevant extraction method. Over the years, a number of different methods have been used, but the efficiency of these methods has rarely been evaluated for soil and leaf litter tardigrades. Four methods of extraction were compared in this study: the light-cooling (L-C) extractor, the high-gradient (H-G), Baermann extractor, the non-gradient (N-G) Baermann extractor and sieves.The results indicate that light and temperature are significant factors influencing tardigrade extraction. The L-C and H-G extractors were more effective than sieves for all substrate categories. These extraction methods (L-C and H-G) therefore seem to be appropriate for quantitative studies of soil and leaf litter tardigrades.

  • 78.
    Czernekova, Michaela
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH). Charles University, Prague.
    Tassidis, Helena
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Holm, Ingvar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Jönsson, K. Ingemar
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Primary Culture of Tardigrade Storage Cells from Richtersius coronifer Richters, 19032016Conference paper (Refereed)
    Abstract [en]

    Coelomocytes are macrophage-like cells in the body cavity or the coelomic spaces of many invertebrates and play major roles in their physiology and immunology. Their structure, function and diversity, however, is still poorly understood.

    Tardigrades are micrometazoans inhabiting a wide variety of environments and with an ability to survive extreme conditions. Coelomocytes (“storage cells”) represent an important part of tardigrade physiology, storing and distributing energy and possibly also having immunological functions. Few studies of tardigrade cell biology have been reported and neither primary nor continuous cell cultures have been established. Tardigrades are normally found and also cultured in an environment rich in microorganisms, some of which may even be of symbiotic value.

    In this study we have tried to establish a primary culture of storage cells in the eutardigrade Richtersius coronifer. Different cell media and concentrations of fetal bovine serum (FBS) were tested. Extracting cells from the tardigrades in an antiseptical environment is challenging since it has to be done under a microscope and contamination from the tardigrades surface is also a problem. To avoid this we tried culturing with high concentrations of antibiotics and antimycotics. We managed to keep the cells viable for up to 18 days in Grace insect medium with 10 % FBS at 20-22°C. The medium was changed every third day. 10x Antibiotic-Antimycotic and 5x of Penicillin-Streptomycin were used to minimize contamination. These concentrations reduce the bacterial abundance, but contamination with fungi was still an issue. Cell morphology evaluation was performed daily and no obvious toxic effects on the cells was observed. Cell viability and cell division were evaluated with Trypan blue staining and cell counting in a haemocytometer. The results indicate that the cells are viable and that some cell division occurs, however more studies need to be performed to confirm this. Still, this study provides the first evidence that primary cultures of storage cells from tardigrades are possible to establish, but the culturing method has to be refined to avoid contamination.

  • 79.
    Dalby, Lars
    et al.
    Department of Bioscience, Aarhus University.
    Söderquist, Pär
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Christensen, Thomas K.
    Department of Bioscience, Aarhus University.
    Clausen, Preben
    Department of Bioscience, Aarhus University.
    Einarsson, Árni
    Myvatn Research Station, Iceland.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Fox, Anthony D.
    Department of Bioscience, Aarhus University.
    Holmqvist, Niklas
    Swedish Association for Hunting and Wildlife Management, Öster Malma, Nyköping.
    Langendoen, Tom
    Wetlands International, Wageningen.
    Lehikoinen, Aleksi
    Finnish Museum of Natural History, University of Helsinki.
    Lindström, Åke
    Department of Biology,Biodiversity, Lund University.
    Lorentsen, Svein-Håkon
    Norwegian Institute for Nature Research, Trondheim.
    Nilsson, Leif
    Department of Biology, Biodiversity, Lund University.
    Pöysä, Hannu
    Finnish Game and Fisheries Research Institute, Joensuu Game and Fisheries Research.
    Sigfússon, Arnór Þ.
    Verkís, Reykjavik.
    Svenning, Jens-Christian
    Ecoinformatics & Biodiversity Group, Department of Bioscience, Aarhus University.
    The status of the Nordic populations of the Mallard (Anas platyrhynchos) in a changing world2013In: Ornis Fennica, ISSN 0030-5685, Vol. 90, no 1, p. 2-15Article in journal (Refereed)
    Abstract [en]

    Dabbling ducks (Anas spp.) are importantmigratory quarry species, protected as a shared resource under international legislation. However, there is a lack of sufficient high-quality data on vital demographic rates and long-term trends in numbers to judge the conservation status of many duck populations at the flyway level. In response to reported declines in the North-West European flyway population of theMallard, we compiled available data on this species in the Nordic countries up to 2010. Generally, national breeding numbers showed increasing trends, wintering abundance showed variable trends, and productivitymeasures indicated stable or increasing trends.Major knowledge gaps were identified, namely the size of hunting bags, the influence of the released Mallards and the role of short-stopping in explaining changing patterns of wintering abundance across the North-West European flyway. Numerically the Nordic breeding population appears in “good condition”, and the wintering numbers have been either stable or increasing in the last two decades. The annual number of releases needs to be determined in order to judge the sustainability of the current levels of exploitation. Overall, none of the indicators showed alarming signs for the Mallard population in the Nordic countries when considered in isolation. However, the widespread decline in wintering numbers elsewhere across North-western Europe requires urgent pan-European action.

  • 80.
    Danell, Kjell
    et al.
    Sveriges lantbruksuniversitet, Umeå.
    Bergström, Roger
    Skogforsk, Uppsala.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Emanuelsson, Urban
    Sveriges lantbruksuniversitet, Alnarp.
    Christiernsson, Anna
    Luleå tekniska universitet.
    Viltet2010In: Vilt, människa, samhälle / [ed] Danell, Kjell, Bergström, Roger, Stockholm: Liber , 2010, p. 17-31Chapter in book (Other (popular science, discussion, etc.))
  • 81.
    Davis, Brian
    et al.
    USA.
    Kaminski, Rick
    USA.
    Eichholz, Mike
    USA.
    Arzel, Celine
    Finland.
    Bearhop, Stuart
    England.
    Eadie, John
    USA.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Fox, Tony
    Danmark.
    Guillemain, Matt
    Frankrike.
    Pearse, Aaron
    USA.
    Stafford, J
    USA.
    Plenary: Waterfowl habitat use and selection: knowledge gained and future science and conservation needs2013In: 6th North American Duck Symposium, Memphis, TN, January 27-31, 2013: ecology and management of North American waterfowl, 2013, p. 9-Conference paper (Refereed)
  • 82.
    Davranche, Aurélie
    et al.
    Frankrike.
    Arzel, Céline
    Frankrike.
    Pöysä, Hannu
    Finland.
    Nummi, Petri
    Finland.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Clausen, Preben
    Danmark.
    Pellikka, Petri
    Finland.
    Assessing habitat suitability for waterbirds along the European flyway using satellite remote sensing2012In: Third Pan-European Duck Symposium, abstract book and progamme, 2012, p. 51-Conference paper (Refereed)
  • 83.
    Davranche, Aurélie
    et al.
    Erlangen-Nürnberg University Institute of Geography.
    Arzel, Céline
    Department of Biology, University of Turku.
    Pöysä, Hannu
    Nummi, Petri
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Clausen, Preben
    Pellikka, Petri
    Lefebvre, Gaëtan
    Poulin, Brigitte
    Space based tools to monitor the habitats of migratory waterbirds2010In: The abstract book: Symposium : The global environmental change: messages from birds. Espoo, 17-19 November, 2010, p. 44-Conference paper (Other academic)
    Abstract [en]

    Natural fluctuations in the availability of suitable habitat coupled with anthropogenic activities (hunting, agriculture, tourism, urbanism) and anticipated modifications due to climate change confront migratory waterbirds with a formidable challenge. Among them, dabbling ducks, greatly rely on local exogenous resources to fulfil their energy requirements. Habitat suitability along their flyway is of primary importance as any change might induce dramatic effects on individual survival and breeding success. Although, the monitoring of such sensitive flooded areas that are wetlands stopover sites is usually complex, space based techniques, with an exhaustive and systematic covering of the territory and a periodical data acquisition, can explore cost-efficiently the ecological conditions for migratory species in these environments. Hence, multiseason reflectance data from radiometrically and geometrically corrected multispectral SPOT-5 scenes, combined with thorough field campaigns and land cover digitizing using data mining, can provide robust tools for habitat monitoring and help the conservation of wetlands for migrants.

  • 84.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment.
    Brochet, A. L.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Legagneux, P.
    Département de Biologie and Centre d’Études Nordiques, Pavillon Vachon Université Laval, Québec.
    Gauthier-Clerc, M.
    Centre de Recherche de la Tour du Valat, Le Sambuc, Arles,.
    Guillemain, M.
    Office National de la Chasse et de la Faune Sauvage, CNERA Avifaune Migratrice, La Tour du Valat, Le Sambuc, Arles.
    Geographical and temporal patterns in the diet of pintail Anas acuta, wigeon Anas penelope, mallard Anas platyrhynchos and teal Anas crecca in the Western Palearctic2011In: European Journal of Wildlife Research, ISSN 1612-4642, E-ISSN 1439-0574, Vol. 57, no 6, p. 1119-1129Article in journal (Refereed)
    Abstract [en]

    Dabbling ducks are important quarry species, and as a result, they are relatively well studied. Over the last century, considerable effort has been made to describe their diet and food requirements. In this review, we compile present knowledge about the diet of four widespread dabbling ducks (wigeon, pintail, mallard and teal) in the Western Palearctic. Previous diet research has a spatio-temporal bias towards autumn/winter and the western parts of Europe. The limited number of studies from the breeding season reveals an increase in invertebrates in the diet compared to other seasons, but with some differences between adults and ducklings. Adult ducks eat a larger proportion of benthic invertebrates, whereas ducklings feed relatively more on emerging invertebrates. The most important plant species (seeds) based on frequency occurrence was found to vary with a geographic gradient. Carex spp., Hordeum vulgare and Hippuris vulgaris are common in the diet of birds at northern latitudes, whereas taxa such as Oryza sativa, Potamogeton pectinatus and Scirpus spp. are common in the south. The reviewed studies are based on the contents of different parts of the digestive system and on a variety of methods to quantify food items. The variations in sampling techniques and shortage of articles from the breeding season and some geographic regions highlight the need for future studies. In the future, it is important to standardize sampling techniques to improve the possibility to compare studies and to obtain a more representative view of the diet of dabbling ducks in Europe.

  • 85.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Är ökande gåsstammar verkligen en skitsak?2007In: Vår fågelvärld, ISSN 0042-2649, Vol. 66, no 7, p. 11-14Article in journal (Other (popular science, discussion, etc.))
  • 86.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Englund, Göran
    Department of Ecology and Environmental Science, Umeå University.
    Pike predation affects breeding success and habitat selection of ducks2011In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 56, no 3, p. 579-589Article in journal (Refereed)
    Abstract [en]

    1. Fish and ducks often belong to the same local food web, and several studies indicate that there is a general negative effect of fish on breeding ducks. This pattern has so far been addressed mainly within the framework of competition for common invertebrate prey, while predation by large fish as a force behind settlement and abundance patterns in ducks remains largely unknown. This is the first study to address the effect of fish predation on breeding ducks, isolated from that of competition, and the first experiment to explore the ability of ducks to identify and avoid lakes with high risk of fish predation. 2. We used a before-after control-impact design and 11 naturally fishless lakes. Waterfowl on the lakes were surveyed during the breeding season of 2005. Large adult pike (Esox lucius) were added to two lakes in early spring 2008, and waterfowl surveys were repeated on all 11 lakes. 3. Pike introduction did not affect the number of pairs on lakes during the nesting season in any of three focal duck species (mallard Anas platyrhynchos, teal Anas crecca, and goldeneye Bucephala clangula). During the brood-rearing season, however, there was a decrease in duck days in teal and goldeneye in lakes with pike, with similar trends observed in mallard. The number of goldeneye ducklings was also significantly lower in lakes with pike. We were unable to determine whether the response was attributable to direct pike predation or to broods leaving experimental lakes, but in either case, our study demonstrates high fitness costs for ducks breeding on lakes with pike. 4. The apparent inability of nesting ducks to detect pike and the clear fitness implications may influence the annual recruitment of ducks on a larger scale as pike are both common and widespread. Vegetation complexity and food abundance are likely to be of overriding importance when breeding ducks are choosing a nesting site. As pike have a strong influence on breeding birds, relying on vegetation and cues of food abundance, while ignoring indicators of predation risk from fish, could lead to lakes with pike acting as an ecological trap.

  • 87.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Health and Society.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Englund, Göran
    Department of Ecology and Environmental Science, Umeå University.
    The effects of pike predation on lake use and reproductive success of ducks: an experimental study in boreal lakes2009In: Abstracts, 2nd Pan-European Duck Symposium, 2009, p. 36-Conference paper (Refereed)
  • 88.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Nummi, Petri
    Finland.
    Pöysä, Hannu
    Finland.
    Sjöberg, Kjell
    SLU, Umeå.
    Hatching in dabbling ducks and emergence in Chironomids: a case of predator-prey synchrony?2011Conference paper (Refereed)
  • 89.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Nummi, Petri
    Department of Forest Ecology, University of Helsinki.
    Pöysä, Hannu
    Finnish Game and Fisheries Research Institute, Joensuu Game and Fisheries Research.
    Sjöberg, Kjell
    Department of Wildlife, Fish and Environmental Studies, Swedish University of Agricultural Sciences, Umeå.
    Hatching in dabbling ducks and emergence in chironomids: a case of predator-prey synchrony?2009In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 636, no 1, p. 319-329Article in journal (Refereed)
    Abstract [en]

    It has been hypothesized that dabbling ducks (Anas spp.) time breeding to coincide with annual regional peaks in emerging dipterans, especially Chironomidae, which are important prey for newly hatched ducklings. However, this hypothesis has never been evaluated in a replicated lake-level study, including year effects in emergence patterns. We collected duck and invertebrate data from 12 lakes during the nesting seasons 1989-1994 in a watershed in southern Finland. The oligotrophic study lakes are typical of the boreal Holarctic, as are the three focal duck species: mallard Anas platyrhynchos L., widgeon Anas penelope L and teal Anas crecca L. Hatching of ducklings showed a clear peak in relation to ambient phenology (annual ice-out date of lakes), whereas chironomid emergence was more erratic and showed no clear peak at the lake level, although total watershed-level emergence was somewhat higher before and long after the duck hatching peak. Thus, we find no evidence that ducklings hatch in synchrony with abundance peaks of emerging chironomids. There was large within-year temporal variation in chironomid emergence among lakes, but this was not correlated with ambient temperature. The rank of individual lakes with respect to the abundance of emerging chironomids was consistent among as well as within years, a predictability that ought to make adaptive lake choice by ducks possible. On the lake level, there was a positive correlation between the total amount of emerging chironomids and brood use. We argue that emergence patterns of chironomids on typical boreal lakes are neither compressed nor predictable enough to be a major selective force on the timing of egg-laying and hatching in dabbling ducks. Despite spatial (among-lake) patterns of abundance of emerging chironomids being predictable within and among years, the observed pattern of brood use suggests that other factors, e.g. habitat structure, also affect lake choice.

  • 90.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Englund, Göran
    Umeå universitet.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Arzel, Céline
    Frankrike.
    Responses of mallard ducklings towards aerial, aquatic and terrestrial predators2012In: Third Pan-European Duck Symposium: abstract book and programme, 2012, p. 17-Conference paper (Refereed)
  • 91.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Englund, Göran
    Department of Ecology and Environmental Science, Umeå University.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Arzél, Celine
    Section of Ecology, Department of Biology, University of Turku.
    Innate responses of mallard ducklings towards aerial, aquatic and terrestrial predators2012In: Behaviour, ISSN 0005-7959, E-ISSN 1568-539X, Vol. 149, no 13-14, p. 1299-1317Article in journal (Refereed)
    Abstract [en]

    Reproductive success in ducks is strongly influenced by predation on the breeding grounds. Ducklings are targeted by a range of terrestrial, aerial and aquatic predators, giving a strong selective advantage to individuals and broods that have effective ways to avoid predation. In experiments on naive mallard (Anas platyrhynchos) ducklings without an accompanying adult female we investigated the innate ability to identify and avoid threats at varying intensity from aerial, aquatic and terrestrial predators. Ducklings displayed increased vigilance in response to pre-recorded calls of predatory birds, representing a low level of threat. They did not react to visual and olfactory stimuli generated by motionless northern pike (Esox lucius). Neither did they show a strong response to caged American mink (Neovison vison) (visual and olfactory stimuli), although they avoided the area with the mink, indicating a certain level of recognition. High intensity threats were simulated by staging attacks from aerial (goshawk, Accipiter gentilis) and aquatic predators (northern pike). The aerial attack made ducklings dive and scatter under water, whereas the response to attack by pike was to run on the water and scatter in different directions. The lack of response to a ‘passive’ pike and the rather weak avoidance of mink indicate that olfactory cues are not as important in identifying a potential predatory threat by ducklings as are auditory cues. Visual cues appear to be of little importance unless they are combined with movement, and a clear response is only triggered when the intensity of predator threat is high. Mallard ducklings, thus, show an innate capacity to adjust anti-predator behaviour to different predator types and to threat intensity. Our study highlights the general trade-off between foraging needs and predator avoidance, but also second-order trade-offs in which innate avoidance behaviour towards one type of predator may increase predation risk from another.

  • 92.
    Dessborn, Lisa
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Hessel, Rebecca
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Geese as vectors of nitrogen and phosphorus to freshwater systems2016In: INLAND WATERS, ISSN 2044-2041, E-ISSN 2044-205X, Vol. 6, no 1, p. 111-122Article in journal (Refereed)
    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.

  • 93.
    Drougge, Diana
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Finns det paleoekologiska spår av en vikingatida storgårdsetablering i Finja, Norra Skåne?: – En pollenanalytisk vegetationsundersökning av Vånga mosse, från yngre järnålder till sen medeltid.2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med uppsatsen är att studera vegetationsutvecklingen och dess förändringar i Finja med hjälp av pollenanalys. De frågor jag önskade få svar på var om det fanns några spår av en vikingatida storgård i Finja, samt eventuella spår av betydande djuruppfödning i området. Finja är rik på fornlämningar från brons-, järnålder och meddeltid, som bekräftar min tes om att Finja/ Mölleröd haft en betydande roll i området runt Finja sjön, troligtvis med odling och handel längs Almaån.

    En paleoekologisk analys genomfördes från en lagerföljd från Vånga mosse, Finja. Totalt togs fyra meter torvprov upp ur mossen. I den översta metern plockades fjorton prover ut till analys. Två 14C dateringar visade vilket tidsspann proven befann sig i. Cirka 600 pollen räknades från varje prov som sedan sammanställdes i olika pollendiagram som visar förändringarna i vegetationen mellan 660 e.Kr. – 1587 e.Kr.

    Vånga mosse visar på kontinuerlig markanvändning under hela den undersökta perioden. Stora förändringar kan ses i pollenkurvorna för odlingsindikatorerna från provets början som ökar till höga värden vid mitten av 700 talet e.Kr. med Secale (råg) som största indikator.  Förändringen visar att området haft en betydande odlingsverksamhet i cirka 150 år under vikingatiden, vilket styrker tesen om en storgårdsetablering i Finja under denna period. Efter odlingsuppgången minskar aktiviteterna i området, dock med fortsatt kontinuitet i både odling- och betesmarker. Området runt Vånga mosse genomgår en kraftig röjning från tidigt 1000 tal e.Kr. till cirka 1200 e.Kr., tillsammans med en expansiv nyodlingsperiod från 1000 e.Kr., som kan ses i båda sädesarterna i diagrammen. Detta resultat tillsammans med andra historiska indikatorer visar på en permanent etablering i Finja vid slutet av 900 e.Kr. Under de nästkommande århundrandena kan ytterligare två nyodlingstoppar ses, en vid mitten av 1000 talet e.Kr. som eventuellt kan kopplas samman med upprättandet av kyrkan, och en vid början av 1200 talet e.Kr.

  • 94.
    Edenius, Lars
    et al.
    Department of Animal Ecology, Swedish University of Agricultural Sciences, Umeå.
    Elmberg, Johan
    Game Division, Finnish Game and Fisheries Research Institute, Helsinki.
    Landscape level effects of modern forestry on bird communities in North Swedish boreal forests1996In: Landscape Ecology, ISSN 0921-2973, E-ISSN 1572-9761, Vol. 11, no 6, p. 325-338Article in journal (Refereed)
    Abstract [en]

    We address effects of large-scale forestry on landscape structure and the structure and composition of boreal bird communities in North Sweden. Specifically, we ask: after controlling for the effect of patch size, forest age and tree species composition, is there any residual effect attributable to the reduction in area of old forest? Pairs of landscape blocks (25 by 25 km) were selected to maximize area difference in human-induced disturbance, clear-cut as opposed to semi-natural old forest. Median distance to natural edge (wetlands, open water) from randomly selected points in forest was 250 and 200 m in high and low impact landscapes, respectively, indicating a high degree of 'natural' fragmentation of the pristine boreal landscape in the area. By contrast, median distance to clear-cut in uncut forest was 750 and 100 m, respectively. Clear-cuts in high impact landscapes were disproportionally more common in areas with contiguous forest land than in areas with spatially disjunct forest, implicating that forestry increases natural fragmentation of the landscape by subdividing larger forest tracts. Point counts along forestry roads showed that species richness and relative abundance of forest birds were higher in landscapes with low forestry impact. These differences can partly be explained by differences in age composition of forest and composition of tree species. After controlling for patch size, forest age and tree species composition, a significant effect of forestry impact remained for Sibirian species and the Tree pipit Anthus trivialis. Our results thus imply that this group of species and the Tree pipit may be sensitive to forest fragmentation. In contrast to previous Finnish studies, we found relatively small negative effects on relative abundance of species hypothesized to be negatively affected by large-scale clear-cutting forestry. However, our picture of the present does not contradict results from Finnish long-term population studies. Five factors may account for this: 1) clear-cut areas are not permanently transformed into other land use types, 2) planted forests are not completely inhabitable for species preferring older forest, 3) the majority of species in the regional pool are habitat generalists, 4) the region studied is still extensively covered with semi-natural forest, and 5) our study area is relatively close to contiguous boreal forest in Russia, a potential source area for taiga species.

  • 95.
    Ehn Börjesson, Stina-Mina
    et al.
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Kühn, Inger
    Department of Microbiology, Tumour and Cell Biology, Karolinska Institute.
    Hernandez, Jorge
    School of Pure and Applied Natural Sciences, Kalmar University.
    Olsen, Björn
    Infectious Diseases, Department of Medical Sciences, Uppsala University.
    Rehnstam-Holm, Ann-Sofi
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Forskningsmiljön Man and Biosphere Health (MABH).
    Enterococcus spp in wastewater and in mallards (Anas platyrhynchos) exposed to wastewater wetland2013In: International Journal of Environmental Protection, ISSN 2226-6437, Vol. 3, no 10, p. 1-12Article in journal (Refereed)
    Abstract [en]

    In this study, twelve Mallards living in an artificial wastewater wetland were exposed to treated wastewater containing 1 x 103- 4 x 103 enterococci 100 ml-1 for a period of 55 days. Faecal samples were collected before, during and after exposure and analysed for Enterococcus spp. The isolates were phenotyped using the PhenePlateTM system. 270 Enterococcus spp. of Mallard origin were analysed, together with 116 Enterococcus spp. isolates from treated wastewater and from incoming raw wastewater. In general, the Mallard and wastewater enterococci isolates belonged to different phenotypes, although several sharing identical phenotypic profiles were found. One E. faecalis phenotype was found in Mallards before, during and after exposure to treated wastewater, as well as in raw and treated wastewater. Our results indicate that there is a common source of enterococci for Mallards and humans. We propose an increased focus on emissions of human bacteria and on systems that mediate their transfer to wild animals.

  • 96.
    Eichholz, Michael W.
    et al.
    USA.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap. Kristianstad University, Research environment Man & Biosphere Health (MABH).
    Nest site selection by Holarctic waterfowl: a multi-level review2014In: Wildfowl, ISSN 0954-6324, E-ISSN 2052-6458, no Special Issue 4, p. 86-130Article in journal (Refereed)
    Abstract [en]

    Because of birds’ mobility, behaviour and many species’ migratory nature, they select repeatedly and spatially among habitats and have been central figures in studies of avian breeding habitat selection during the 20th and 21st centuries. The scientific literature on habitat use by breeding waterfowl has origins dating back to the writings of Charles Darwin in The Voyage of the Beagle, wherein he described the distribution and habitat differences of two species of geese on the Falkland Islands. Since that time, waterfowl ecologists have gone from descriptive studies of nest site characteristics used for planning waterfowl conservation and management to comparing nest site use in relation to potential habitat availability and determining selection for a wide array of ecological correlates. Waterfowl ecologists most recently have been investigating the adaptive significance of nest site selection by associating the latter with individual fitness and demographic measurements to assess the birds’ adaptability under environmental conditions at multiple scales of selection. While little direct assessment of 1st and 2nd order nest site selection has occurred (sensu Johnson 1980), available information is most consistent with the hypothesis that selection at these scales is driven by food availability. At the 3rd and 4th order of selection, data are consistent with hypotheses that both food availability and predator avoidance drive nest site selection, depending on the species and type of nesting aggregation. We also identify understudied areas of nest site selection important for the conservation and management of waterfowl and suggest that the large-scale influence of current anthropogenic and natural effects on the environment indicates that greater emphasis should be directed toward understanding waterfowl nest site selection at the 1st and 2nd orders of selection and how nesting habitat selection interfaces with community ecology of sympatric breeding waterfowl. Moreover, because habitat selection of prefledging waterfowl is inherently linked to breeding habitat selection, we suggest an updated review of brood habitat selection should ensue from our synthesis here.

  • 97.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Adaptiv skötsel av europeiska simänder för jakt, naturvård och sjukdomseffekter – slutår2011Report (Other academic)
    Abstract [en]

    This project concludes studies started during a 3-year project already reported to Naturvårdsverket. Recent unreported achievements include a phD project, 16 scientific manuscripts, 12 conference contributions and 10 popular papers. Results and management implications from these studies are summarized in this report. We highlight a previously overlooked potential conflict between fish stocking and duck management. We argue that the tools necessary for adopting an adaptive management of Swedish dabbling ducks are available, and that the success of such a paradigm shift in game management is enhanced if also programs are put in place to monitor changes in breeding population size and annual breeding success. Experiments and descriptive studies indicate that mallards are not affected by moderate changes in the arrival of spring, and that there is little duckling-food prey synchrony to become potentially mis-matched. We also argue it is important to continue monitoring avian influenza in wild ducks in Sweden.

  • 98. Elmberg, Johan
    Apparent lack of territoriality during the breeding season in a boreal population of common frogs Rana temporaria L.1986In: Herpetological Journal, ISSN 0268-0130, Vol. 1, no 2, p. 81-85Article in journal (Refereed)
  • 99.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment.
    Are dabbling ducks main players or merely noise in limnic ecosystems?2009In: Abstracts, 2nd Pan-European Duck Symposium, 2009, p. 25-Conference paper (Refereed)
    Abstract [en]

    For obvious reasons waterfowl ecologists consider ducks as focal organisms and main players when we study patterns and processes in wetland ecosystems. However, limnologists and fish biologists historically have ‘a bottom-up’ view of the same ecosystems, and they largely regard ducks and other waterbirds merely as ‘background noise’ much at the mercy of other and more powerful forces. Focussing on European studies of dabbling ducks I will review the evidence for and against these largely opposing views. I argue that a lot can be learned from using descriptive and pattern-oriented studies to produce explicit predictions that can be tested under more rigorous experimental circumstances. I will also explore why the lack of reliable information about annual variations in recruitment and harvest rates is a major obstacle for understanding population trajectories of dabbling duck populations. Finally, I will review the existing evidence for the major paradigms addressing population limitation in European dabbling ducks.

  • 100.
    Elmberg, Johan
    Kristianstad University, School of Education and Environment, Avdelningen för Naturvetenskap.
    Are dabbling ducks major players or merely noise in freshwater ecosystems?: a European perspective, with references to population limitation and density dependence2009In: Wildfowl, ISSN 0954-6324, E-ISSN 2052-6458, no Special issue 2, p. 9-23Article in journal (Refereed)
    Abstract [en]

    Waterfowl ecologists consider ducks important players in patterns and processes of freshwater ecosystems. Limnologists and fish biologists, on the other hand, historically have “a bottom-up” view of the same systems, often regarding waterbirds as “background noise” compared to other biotic influences. Evidence for and against these largely opposing views is reviewed, focussing on European dabbling duck studies. In oligo- and mesotrophic wetlands at low breeding density, their role is likely to be overshadowed by biotic interactions between fish, invertebrates and plants. Conversely, many other freshwater systems may be affected by dabbling ducks in various ways, acting as dispersers of invertebrates and plants, as predators, and as eutrophicators. It is concluded that dabbling ducks affect freshwater systems more profoundly than has hitherto been acknowledged. In their turn, freshwater ecosystems affect the ducks’ population ecology. In a less comprehensive treatment, the evidence for the major paradigms addressing population limitation in dabbling ducks is discussed briefly from a European perspective. It is concluded that top-down (predation) as well as bottom-up (food limitation) processes may both affect population size, but evidence for either is correlative, necessitating more experimental studies based on explicit predictions from pattern-oriented studies. In a discussion of the prospects for adopting a more adaptive management approach for European dabbling ducks, it is argued that a lack of information about annual variation in recruitment and harvest rates are major obstacles to understanding population change and for adopting a more adaptive management. A compilation of European studies about density dependence in Mallard Anas platyrhynchos indicates that population regulation may be a common phenomenon in this species, with possible important ramifications for research as well as management programmes.

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