hig.sePublications
Change search
Refine search result
1 - 45 of 45
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Andersson, Erik
    et al.
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden .
    Barthel, Stephan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Environmental engineering. Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Memory carriers and stewardship of metropolitan landscapes2016In: Ecological Indicators, ISSN 1470-160X, E-ISSN 1872-7034, Vol. 70, p. 606-614Article in journal (Refereed)
    Abstract [en]

    History matters, and can be an active and dynamic component in the present. We explore social-ecological memory as way to diagnose and engage with urban green space performance and resilience. Rapidly changing cities pose a threat and a challenge to the continuity that has helped to support biodiversity and ecological functions by upholding similar or only slowly changing adaptive cycles over time. Continuity is perpetuated through memory carriers, slowly changing variables and features that retain or make available information on how different situations have been dealt with before. Ecological memory carriers comprise memory banks, spatial connections and mobile link species. These can be supported by social memory carriers, represented by collectively created social features like habits, oral tradition, rules-in-use and artifacts, as well as media and external sources. Loss or lack of memory can be diagnoses by the absence or disconnect between memory carriers, as will be illustrated by several typical situations. Drawing on a set of example situations, we present an outline for a look-up table approach that connects ecological memory carriers to the social memory carriers that support them and use these connections to set diagnoses and indicate potential remedies. The inclusion of memory carriers in planning and management considerations may facilitate preservation of feedbacks and disturbance regimes as well as species and habitats, and the cultural values and meanings that go with them.

  • 2.
    Andersson, Erik
    et al.
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden; Beijer Institute, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Barthel, Stephan
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Borgström, Sara
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Colding, Johan
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden; The Beijer Institute, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Elmqvist, Thomas
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Folke, Carl
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden; The Beijer Institute, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Gren, Åsa
    The Beijer Institute, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Reconnecting Cities to the Biosphere: Stewardship of Green Infrastructure and Urban Ecosystem Services2014In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 43, no 4, p. 445-453Article in journal (Refereed)
    Abstract [en]

    Within-city green infrastructure can offer opportunities and new contexts for people to become stewards of ecosystem services. We analyze cities as social-ecological systems, synthesize the literature, and provide examples from more than 15 years of research in the Stockholm urban region, Sweden. The social-ecological approach spans from investigating ecosystem properties to the social frameworks and personal values that drive and shape human interactions with nature. Key findings demonstrate that urban ecosystem services are generated by social-ecological systems and that local stewards are critically important. However, land-use planning and management seldom account for their role in the generation of urban ecosystem services. While the small scale patchwork of land uses in cities stimulates intense interactions across borders much focus is still on individual patches. The results highlight the importance and complexity of stewardship of urban biodiversity and ecosystem services and of the planning and governance of urban green infrastructure.

  • 3.
    Andersson, Tony
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Habitatval hos yngel av öring (Salmo trutta) i en undersökning i Nedre Dalälven2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this project was to examine important parameters for juvenile brown trout habitat selection in their first months after hatching. The study was carried out after approximately 30 000 fry had been released by the County Administrative Board of Gävleborg. Data on habitat selection was collected from five different localities at the river Dalälven, near Gysinge, Sweden. The method of estimating preferred habitat was to determine remaining fry after a period of seven weeks by electrofishing.

    This study confirms that the optimal local habitat choice for juvenile trout is where the substrate size 60- 200 mm is present and a hypothesis is proposed that this substrate is of importance for juvenile trout survival as it gives shelter in the presence of predators. Based on previous research the study gives some suggestions to which important habitat characteristics that were missing where no trout were recaptured.

  • 4.
    Barthel, Stephan
    et al.
    Natural Resource Management, Department of Systems Ecology, Stockholm University, Stockholm, Sweden; Beijer Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden; Stockholm Resilience Center, Stockholm University, Stockholm, Sweden.
    Folke, Carl
    Natural Resource Management, Department of Systems Ecology, Stockholm University, Stockholm, Sweden; Beijer Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden; Stockholm Resilience Center, Stockholm University, Stockholm, Sweden.
    Colding, Johan
    Beijer Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden; Stockholm Resilience Center, Stockholm University, Stockholm, Sweden.
    Social-ecological memory in urban gardens-Retaining the capacity for management of ecosystem services2010In: Global Environmental Change, ISSN 0959-3780, E-ISSN 1872-9495, Vol. 20, no 2, p. 255-265Article in journal (Refereed)
    Abstract [en]

    Many ecosystem services are in decline. Local ecological knowledge and associated practice are essential to sustain and enhance ecosystem services on the ground. Here, we focus on social or collective memory in relation to management practice that sustains ecosystem services, and investigate where and how ecological practices, knowledge and experience are retained and transmitted. We analyze such social-ecological memory of allotment gardens in the Stockholm urban area, Sweden. Allotment gardens support ecosystem services such as pollination, seed dispersal and pest regulation in the broader urban landscape. Surveys and interviews were preformed over a four-year period with several hundreds of gardeners. We found that the allotment gardens function as communities-of-practice, where participation and reification interact and social-ecological memory is a shared source of resilience of the community by being both emergent and persistent. Ecological practices and knowledge in allotment gardens are retained and transmitted by imitation of practices, oral communication and collective rituals and habits, as well as by the physical gardens, artifacts, metaphors and rules-in-use (institutions). Finally, a wider social context provides external support through various forms of media, markets, social networks, collaborative organizations, and legal structures. We exemplify the role of urban gardens in generating ecosystem services in times of crisis and change and conclude that stewards of urban green areas and the social memory that they carry may help counteract further decline of critical ecosystem services. .

  • 5.
    Berg, Björn
    et al.
    University of Helsinki, Helsinki, Finland.
    Erhagen, Björn
    Swedish University of Agricultural Sciences, Umeå, Sweden.
    Johansson, Maj-Britt
    University of Gävle.
    Vesterdal, Lars
    University of Copenhagen, Denmark.
    Faituri, Mikaeel
    Omar AlMuktar University, Elbeida, Libya.
    Sanborn, Paul
    University of British Columbia, Prince George, Canada.
    Nilsson, Mats
    Swedish University of Agricultural Sciences, Umeå, Sweden.
    Manganese dynamics in decomposing needle and leaf litter: a synthesis2013In: Canadian Journal of Forest Research, ISSN 0045-5067, E-ISSN 1208-6037, Vol. 43, no 12, p. 1127-1136Article in journal (Refereed)
    Abstract [en]

    The aim of the present synthesis paper was to determine whether concentration changes and net release of manganese (Mn), as related to accumulated litter mass loss, are related to initial Mn concentration, mean annual temperature (MAT), mean annual precipitation (MAP), and tree genus or species. We also examined whether limit values for decomposition are related to initial litter Mn concentration, MAT, and MAP. We compiled 84 foliar litter decomposition studies, conducted mainly in boreal and temperate forest ecosystems, for which Mn dynamics had been well documented. Manganese concentration and amount were related to accumulated litter mass loss at each sampling time for each single study, as well as for (i) all studies combined (n = 748) and (ii) for species groups viz. Norway spruce (Picea abies (L.) Karst.) (n = 284), pine (Pinus) species (n = 330), and deciduous species (n = 214). The changes in Mn concentration with accumulated mass loss followed quadratic functions showing significantly higher Mn concentrations for Norway spruce vs. Scots pine (Pinus sylvestris L.) (p < 0.0001) and vs. deciduous species (p < 0.01), as well as significantly higher for deciduous species vs. Scots pine (p < 0.0001). Manganese release rates were different among the three species groups (p < 0.001). Still, rates were related to initial Mn concentrations (p < 0.001) for all litter types combined and for the three species groups. Norway spruce released Mn more slowly than pine and deciduous species. Rates were related to climatic factors for litter of Norway spruce and deciduous species. Limit values for all litter and for pine species separately were related to Mn (p < 0.001) and MAT (p < 0.001). For Norway spruce, limit values were related to MAT (p < 0.001) and MAP (p < 0.01). It appears that Norway spruce litter retains Mn more strongly in the litter structure, producing humus richer in Mn than does litter of pine and deciduous species.

  • 6.
    Berkes, Fikret
    et al.
    Natural Resources Institute, University of Manitoba, Canada.
    Colding, Johan
    Centre for Research on Natural Resources and the Environment, Stockholm University, Stockholm, Sweden; Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Folke, Carl
    Centre for Research on Natural Resources and the Environment (CNM), Stockholm University, Stockholm, Sweden; Department of Systems Ecology Stockholm University, Stockholm, Sweden; Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Introduction2002In: Navigating Social-Ecological Systems: Building Resilience for Complexity and Change / [ed] Berkes, F., Colding, J. and Folke, C., Cambridge: Cambridge University Press, 2002, 1, , p. 393p. 1-29Chapter in book (Refereed)
    Abstract [en]

    A common perspective until recently was that our problem-solving abilities have been improving over the years. In the area of resource and environmental management, for example, there was a great deal of faith in our growing scientific understanding of ecosystems, our bag of increasingly sophisticated tools and technologies, and the application of market mechanisms to problems such as air pollution control and fishery management through individually allocated quotas. However, the experience over the last few decades does not support such optimism (e.g., Clark and Munn, 1986; Ludwig, Hilborn, and Walters, 1993; Gunderson, Holling, and Light, 1995). Many of our resource and environmental problems are proving resistant to solutions. A gap has developed between environmental problems and our lagging ability to solve them. This is coming at a time when the Earth has become an increasingly human-dominated system. Many of the changes in the biosphere, including the modification of landscapes, loss of biodiversity and, according to some, climate change, are driven by human activities. Furthermore, changes are occurring at an increasingly faster rate than previously experienced in human history.

    There is an emerging consensus regarding the need to look for broader approaches and solutions, not only with resource and environmental issues but along a wide front of societal problems. A survey of senior American Association for the Advancement of Science (AAAS) scientists revealed an intriguing insight.

  • 7.
    Berkes, Fikret
    et al.
    Natural Resources Institute, University of Manitoba, Canada.
    Colding, Johan
    Centre for Research on Natural Resources and the Environment, Stockholm University, Stockholm, Sweden; Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Folke, Carl
    Centre for Research on Natural Resources and the Environment (CNM), Stockholm University, Stockholm, Sweden; Department of Systems Ecology Stockholm University, Stockholm, Sweden; Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Living with disturbance: Building resilience in social-ecological systems2002In: Navigating Social-Ecological Systems: Building Resilience for Complexity and Change / [ed] Berkes, F., Colding, J. and Folke, C., Cambridge: Cambridge University Press, 2002, 1, , p. 393p. 163-186Chapter in book (Refereed)
    Abstract [en]

    Disturbances such as fire, cyclones, and pest outbreaks create variation in natural systems and ecosystem renewal that may be important for the maintenance of biological diversity. Many natural disturbances are inherent in the internal dynamics of ecosystems, and often set the timing of ecosystem renewal processes fundamental for maintaining resilience in ecosystems (Holling et al., 1995).

    By disturbance we mean ‘any relatively discrete event in time that disrupts ecosystem community or population structure and changes resources, substrate availability, or the physical environment’ (White and Pickett, 1985: 7). We distinguish between abiotic and biotic disturbances. Abiotic disturbances are those where the direct cause of disturbance is generated by nonbiotic agents. Examples include fires, hurricanes, volcanic eruptions, earthquakes, flooding, and drought. Examples of biotic disturbances include insect and pest attacks, predators, invasion of exotic species, and the grazing and browsing of herbivores.

    Conventional resource management, based on economic production targets, commonly seeks to reduce natural variation in target resources, because fluctuations impose problems for the industry dependent on the resource (Holling and Meffe, 1996). Control of resource stock variability and flows can be achieved in a number of ways. For instance, by increasing financial investments in technologies for harvesting, a modern fishing industry can invest in larger fleets and more effective gear in order to maintain an even flow of production. Maintenance of high and even flows of monoculture crops in large-scale agriculture may be achieved by investing in various energy inputs, such as insecticides, pesticides, and irrigation.

  • 8.
    Berkes, Fikret
    et al.
    University of Manitoba, Canada.
    Colding, JohanBeijer International Institute of Ecological Economics, Stockholm, Sweden.Folke, CarlBeijer International Institute of Ecological Economics, Stockholm, Sweden.
    Navigating Social-Ecological Systems: Building Resilience for Complexity and Change2002Collection (editor) (Refereed)
    Abstract [en]

    In the effort towards sustainability, it has become increasingly important to develop conceptual frames to understand the dynamics of social and ecological systems. Drawing on complex systems theory, this book investigates how human societies deal with change in linked social-ecological systems, and build capacity to adapt to change. The concept of resilience is central in this context. Resilient social-ecological systems have the potential to sustain development by responding to and shaping change in a manner that does not lead to loss of future options. Resilient systems also provide capacity for renewal and innovation in the face of rapid transformation and crisis. The term navigating in the title is meant to capture this dynamic process. Case studies and examples from several geographic areas, cultures and resource types are included, merging forefront research from natural sciences, social sciences and the humanities into a common framework for new insights on sustainability.

  • 9.
    Berkes, Fikret
    et al.
    Natural Resources Institute, University of Manitoba, Canada.
    Colding, Johan
    Centre for Research on Natural Resources and the Environment, Stockholm University, Stockholm, Sweden; Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Folke, Carl
    Centre for Research on Natural Resources and the Environment (CNM), Stockholm University, Stockholm, Sweden; Department of Systems Ecology Stockholm University, Stockholm, Sweden; Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Synthesis: Building Resilience and Adaptive Capacity in Social-Ecological Systems2002In: Navigating Social-Ecological Systems: Building Resilience for Complexity and Change / [ed] Berkes, F., Colding, J. and Folke, C., Cambridge: Cambridge University Press, 2002, 1, , p. 393p. 352-387Chapter in book (Refereed)
    Abstract [en]

    A weekly magazine on business development issued an analysis of Madonna, the pop star, and raised the question ‘How come Madonna has been at the very top in pop music for more than 20 years, in a sector characterized by so much rapid change?’ A few decades ago, successful companies developed their brand around stability and security. To stay in business this is no longer sufficient, according to the magazine. You must add change, renewal, and variation as well. However, change, renewal, and variation by themselves will seldom lead to success and survival. To be effective, a context of experience, history, remembrance, and trust, to act within, is required. Changing, renewing, and diversifying within such a foundation of stability and maintaining high quality have been the recipe for success and survival of Madonna, and for rock stars such as Neil Young and U2. It requires an active adaptation to change, not only responding to change, but also creating and shaping it. In the same spirit, Sven-Göran Eriksson, coach of several soccer teams in Europe, claimed that it is the wrong strategy not to change a winning team. A winning team will always need a certain amount, but not too much, of renewal to be sustained as a winning team. Sustaining a winning team requires a context for renewal, or ‘framed creativity,’ borrowing from the language of the advertiser.

  • 10.
    Betzholtz, Per-Eric
    et al.
    School of Natural Sciences, Linnaeus University, Kalmar, Sweden .
    Pettersson, Lars B
    Department of Biology, Lund University, Lund, Sweden .
    Ryrholm, Nils
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Franzén, Markus
    Helmholtz Centre for Environmental Research, Halle, Germany .
    With that diet, you will go far: trait-based analysis reveals a link between rapid range expansion and a nitrogen-favoured diet2013In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 280, no 1750, p. 1-6Article in journal (Refereed)
    Abstract [en]

    Recent global change has had a substantial influence on the distribution of organisms, and many species are currently expanding their ranges. To evaluate the underlying processes, long-term data with good geographic resolution are essential. One important but generally overlooked data source is offered by the taxon-specific national catalogues of first provincial records that are kept in many countries. Here, we use such data to quantify trait-based influences on range expansion in Swedish butterflies and moths between 1973 and 2010. Of 282 species meeting pre-defined quality criteria, 170 expanded their northern range margin, with a mean expansion rate of 2.7 km per year. The analyses demonstrate that habitat and diet generalists, forest species and species active during warm conditions have expanded their ranges more rapidly than other species. Notably, range expansion in diet specialists was positively related to a nitrogen-favoured larval diet, an effect not found among oligo- or polyphagous species. In contrast to the general view, this shows that specialist species can undergo rapid range expansion. We suggest that increased areas of nitrogen-rich habitat, and increased availability of a nitrogen-favoured diet, are among the most important drivers of range expansions, potentially having far-reaching consequences for a wide variety of organisms.

  • 11.
    Björk, Robert G.
    et al.
    Department of Plant and Environmental Sciences, Göteborg University, Gothenburg, Sweden.
    Majdi, Hooshang
    Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Klemedtsson, Leif
    Department of Plant and Environmental Sciences, Göteborg University, Gothenburg, Sweden.
    Lewis-Johnsson, Lotta
    Department of Plant and Environmental Sciences, Göteborg University, Gothenburg, Sweden.
    Molau, Ulf
    Department of Plant and Environmental Sciences, Göteborg University, Gothenburg, Sweden.
    Long-term warming effects on root morphology, root mass distribution, and microbial activity in two dry tundra plant communities in northern Sweden2007In: New Phytologist, ISSN 0028-646X, E-ISSN 1469-8137, Vol. 176, no 4, p. 862-873Article in journal (Refereed)
    Abstract [en]

    • Effects of warming on root morphology, root mass distribution and microbialactivity were studied in organic and mineral soil layers in two alpine ecosystems over > 10 yr, using open-top chambers, in Swedish Lapland.

    • Root mass was estimated using soil cores. Washed roots were scanned and sortedinto four diameter classes, for which variables including root mass (g dry matter(g DM) m –2 ), root length density (RLD; cm cm –3 soil), specific root length (SRL; m gDM –1 ), specific root area (SRA; m 2 kg DM –1 ), and number of root tips m –2 weredetermined. Nitrification (NEA) and denitrification enzyme activity (DEA) in the top10 cm of soil were measured.

    • Soil warming shifted the rooting zone towards the upper soil organic layer in bothplant communities. In the dry heath, warming increased SRL and SRA of the finestroots in both soil layers, whereas the dry meadow was unaffected. Neither NEA norDEA exhibited differences attributable to warming.

    • Tundra plants may respond to climate change by altering their root morphologyand mass while microbial activity may be unaffected. This suggests that carbon maybe incorporated in tundra soils partly as a result of increases in the mass of the finerroots if temperatures rise.

  • 12.
    Bringmark, Ewa
    et al.
    Department of Aquatic Sciences and Assessment, SLU, Uppsala, Sweden.
    Bringmark, Lage
    Department of Aquatic Sciences and Assessment, SLU, Uppsala, Sweden.
    Sonesten, Lars
    Department of Aquatic Sciences and Assessment, SLU, Uppsala, Sweden .
    Mjöfors, Kristina
    Department of Soil and Environment, SLU, Uppsala, Sweden.
    Johansson, Maj-Britt
    University of Gävle.
    Long-term monitoring of scots pine litter decomposition rates throughout sweden indicates formation of a more recalcitrant litter in the south2011In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, no 8, p. 878-890Article in journal (Refereed)
    Abstract [en]

    Decomposition studies were carried out at sites throughout Sweden, including the four Integrated Monitoring sites. Scots pine needle litterbag weight loss measurements over 3 or 5 years were determined at 26 sites and repeated up to 27 times, depending on the site. Humus layer respiration rates were determined for 20 sites in 1987-1989 and repeated in 2007-2008. Partial Least Squares (PLS) regression was used to elucidate the relative importance of climatic and soil factors. Annual needle weight losses decreased only slowly (20-10%) over 3-5 years for all northern (> 60A degrees N) sites but decreased sharply from 30 to 10% in the third year in southern (< 60A degrees N) sites. Respiration rates of southern sites were less (40% on average) than those of northern sites. Humus layer N was positively correlated to needle weight loss during the first and the second years, but negatively correlated in the third year and to respiration rates. The results indicated that litter formed in southern Sweden became more recalcitrant in later stages of decomposition compared to litter produced in northern Sweden.

  • 13.
    Cassel-Lundhagen, Anna
    et al.
    Swedish University of Agricultural Sciences, Dept of Ecology, Uppsala, Sweden.
    Tammaru, Toomas
    Institute of Ecology, and Earth Sciences, University of Tartu, Tartu, Estonia.
    Windig, Jack
    Animal Breeding and Genomics Centre, Animal Sciences Group, Wageningen UR, Lelystad, Netherlands.
    Ryrholm, Nils
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Nylin, Sören
    Department of Zoology, Stockholm University, Stockholm, Sweden.
    Are peripheral populations special? Congruent patterns in two butterfly species2009In: Ecography, ISSN 0906-7590, E-ISSN 1600-0587, Vol. 32, no 4, p. 591-600Article in journal (Refereed)
    Abstract [en]

    Populations at range margins may be genetically different from more central ones for a number of mutually non-exclusive reasons. Specific selection pressures may operate in environments that are more marginal for the species. Genetic drift may also have a strong effect in these populations if they are small, isolated and/or have experienced significant bottlenecks during the colonisation phase. The question if peripheral populations are special, and if yes then how and why, is of obvious relevance for speciation theory, as well as for conservation biology. To evaluate the uniqueness of populations at range margins and the influence of gene flow and selection, we performed a morphometric study of two grassland butterfly species: from Swedish populations that are peripheral and isolated from the main area of the species distributions and from populations in the Baltic states that are peripheral but connected to the main area of the species distributions. These samples were compared to those from central parts of the species distributions. The isolated populations in both species differed consistently from both peripheral and central populations in their wing size and shape. We interpret this as a result of selection caused by differences in population structure in these isolated locations, presumably favoring different dispersal propensity of these butterflies. Alternative explanations based on colonisation history, latitudinal effects, inbreeding or phenotypic plasticity appear less plausible. As a contrast, the much weaker and seemingly random amongregion differences in wing patterns are more likely to be ascribed to weaker selection pressures allowing genetic drift to be influential. In conclusion, both morphological data and results from neutral genetic markers in earlier studies of the same system provide congruent evidence of both adaptation and genetic drift in the isolated Swedish populations of both species.

     

  • 14.
    Colding, Johan
    et al.
    The Beijer Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden; Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Barthel, Stephan
    The Beijer Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden; Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden; Department of History, Stockholm University, Stockholm, Sweden.
    The potential of ‘Urban Green Commons’ in the resilience building of cities2013In: Ecological Economics, ISSN 0921-8009, E-ISSN 1873-6106, Vol. 86, p. 156-166Article in journal (Refereed)
    Abstract [en]

    While cultural diversity is increasing in cities at a global level as a result of urbanization, biodiversity is decreasing with a subsequent loss of ecosystem services. It is clear that diversity plays a pivotal role in the resilience building of ecosystems; however, it is less clear what role cultural diversity plays in the resil- ience building of urban systems. In this paper we provide innovative insights on how common property sys- tems could contribute to urban resilience building. Through a review of recent findings on urban common property systems and the relevant literature, we deal with urban green commons (UGCs) and discuss their potential to manage cultural and biological diversity in cities. We describe three examples of UGCs, i.e. col- lectively managed parks, community gardens, and allotment areas, with a focus on their institutional characteristics, their role in promoting diverse learning streams, environmental stewardship, and social– ecological memory. We discuss how UGCs can facilitate cultural integration through civic participation in urban land-management, conditions for the emergence of UGCs, the importance of cognitive resilience building, and what role property-rights diversity plays in urban settings. We conclude by elucidating some key insights on how UGCs can promote urban resilience building.

  • 15.
    Colding, Johan
    et al.
    The Beijer Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden; he Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden; .
    Lundberg, Jakob
    he Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Lundberg, Stefan
    The Swedish Museum of Natural History, Stockholm, Sweden.
    Andersson, Erik
    Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Alnarp, Sweden.
    Golf courses and wetland fauna2009In: Ecological Applications, ISSN 1051-0761, E-ISSN 1939-5582, Vol. 19, no 6, p. 1481-1491Article in journal (Refereed)
    Abstract [en]

    Golf courses are often considered to be chemical‐intensive ecosystems with negative impacts on fauna. Here we provide evidence that golf courses can contribute to the support and conservation of wetland fauna, i.e., amphibians and macroinvertebrates. Comparisons of amphibian occurrence, diversity of macroinvetebrates, and occurrence of species of conservation concern were made between permanent freshwater ponds surveyed on golf courses around Sweden's capital city, Stockholm, and off‐course ponds in nature‐protected areas and residential parklands. A total of 71 macroinvertebrate species were recorded in the field study, with no significant difference between golf course ponds and off‐course ponds at the species, genus, or family levels. A within‐group similarities test showed that golf course ponds have a more homogenous species composition than ponds in nature‐protected areas and ponds in residential parkland. Within the macroinvertebrate group, a total of 11 species of odonates were identified, with no difference detected between the categories of ponds, nor any spatial autocorrelation. Significant differences were found between pond categories in the occurrence of five species of amphibians, although anuran occurrence did not differ between ponds. The great crested newt (Triturus cristatus) was significantly associated with golf course ponds, but the smooth newt (Triturus vulgaris) was not. We found no evidence of any correlation between pond size and occurrence of amphibians. Among the taxa of conservation concern included in the sample, all amphibians are nationally protected in Sweden, with the internationally threatened T. cristatus more frequently found in golf course ponds. Among macroinveterbrates of conservation status, the large white‐faced darter dragonfly (Leucorrhinia pectoralis) was only detected in golf course ponds, and Tricholeiochiton fagesi (Trichoptera) was only found in one off‐course pond. GIS results revealed that golf courses provide over a quarter of all available permanent, freshwater ponds in central greater Stockholm. We assert that golf courses have the potential to contribute to wetland fauna support, particularly in urban settings where they may significantly contribute to wetland creation. We propose a greater involvement of ecologists in the design of golf courses to further bolster this potential.

  • 16.
    Djerdali, Sofia
    et al.
    Département de Biologie, Université Farhat Abbes, Sétif, Algeria.
    Sanchez Tortosa, Francisco
    Univ Cordoba, Dept Zool, Cordoba, Spain.
    Hillström, Lars
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Doumandji, Salaheddine
    Ecole Nationale Supérieure d'Agronomie, El Harrach, Algeria.
    Food supply and external cues limit the clutch size and hatchability in the White Stork Ciconia ciconia2008In: Acta Ornithologica, ISSN 0001-6454, E-ISSN 1734-8471, Vol. 43, no 2, p. 145-150Article in journal (Refereed)
    Abstract [en]

    Clutch size is an important life history trait and factors such as nest predation and food availability can both be of crucial importance for its variation in nature. The aim of the present study was to evaluate the effects of extra food on clutch size, laying date and hatching success in the White stork Ciconia ciconia. Three different colonies of White stork were studied over a three-year period where there was difference in both food availability and precipitation. This study demonstrated that an extra food supply during the pre-laying period had a positive effect on clutch size - nests with extra food had a larger clutch size. There was also an advance in laying date and a higher hatching success in nests with access to extra food. In addition to food supply, clutch size was independently affected by rainfall, which suggests that parents additionally also were sensitive to other external cues than to the extra food. Furthermore, this study also suggests that an extra food during the incubation period could probably help the parents to solve the conflict between incubation behaviour and minimizing the time off the nest, i.e. increasing nest attentiveness in nests with extra food.

  • 17.
    Eckersten, Henrik
    et al.
    Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Marstorp, Håkan
    Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Collentine, Dennis
    University of Gävle, Faculty of Education and Business Studies, Department of Business and Economic Studies, Economics. Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Johnsson, Holger
    Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Kätterer, Thomas
    Department of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Ecosystem C and N dynamics affected by a modified spring barley trait with increased nitrogen use - a simulation case study2018In: Acta Agriculturae Scandinavica - Section B, ISSN 0906-4710, E-ISSN 1651-1913, Vol. 68, no 3, p. 230-242Article in journal (Refereed)
    Abstract [en]

    To what extent might a crop with increased plant N uptake efficiency and/or N demand increase plant biomass and soil carbon storage, decrease N leaching, and reduce the need for N fertilisation? This was assessed for a fertilised sandy loam site in central Sweden cultivated with spring barley for a four year period using a process based crop and soil simulation model (SOILN) calibrated to fit observations of field experiments with non-modified crops. Crop properties were changed in accordance with previous model applications to other crops with higher N uptake and utilisation efficiencies, to resemble potential effects of breeding. For the modified crops a doubling of daily uptake efficiency of soil mineral N and/or increase of radiation use efficiency by 30%, increased plant biomass by 3%-30%, decreased N leaching by 1%-30% and increased soil organic carbon (SOC) content by 1-12 g C m-2 year-1. The larger changes were mainly due to increased uptake efficiency. Fertilisation of the modified spring barley crop could be reduced while still producing the same plant biomass as the non-modified crop. The plant biomass to N leaching ratio of the modified crops increased. The simulated changes in plant biomass and SOC were sensitive to weather conditions suggesting that in situ experiments would need to cover a large range of weather conditions to evaluate the performance of new crop traits under climatic variability. The study suggests a strong need that field experiments are accompanied with model applications, when exploring the potential of the modified crops under variable conditions.

  • 18.
    Elmqvist, Tomas
    et al.
    Stockholm University, Stockholm, Sweden.
    Alfsen, C.
    UNESCO, New York, NY, USA.
    Colding, Johan
    Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Urban Systems2008In: Encyclopedia of Ecology / [ed] Sven Erik Jørgensen and Brian D. Fath, Oxford: Academic Press, 2008, p. 3665-3672Chapter in book (Other academic)
    Abstract [en]

    Urbanization is a global multidimensional process which manifests itself through rapidly changing human population densities and changing land cover. Urbanization is viewed today as endangering more species and as more geographically ubiquitous than any other human activity and also the major driving force for increased homogenization of fauna and flora. The concept of ecosystem services has proven useful in describing human benefits from urban ecosystems. For example, urban vegetation may significantly reduce air pollution, mitigate the urban heat island effect, reduce noise, and enhance recreational and cultural values, of importance for urban citizen’s wellbeing. New opportunities lie in that urban landscapes are the very places where knowledge, innovation, and human and financial resources for getting solutions to global environmental problems are likely to be found.

  • 19.
    Ernstson, Henrik
    et al.
    Stockholms universitet, Systemekologiska institutionen.
    Barthel, Stephan
    Andersson, Erik
    Borgström, Sara
    Ecological scales and social network structure: management and governance of urban ecosystem services in Stockholm, SwedenManuscript (preprint) (Other academic)
  • 20.
    Ernstson, Henrik
    et al.
    Department of Systems Ecology, Stockholm University, Stockholm, Sweden; Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden.
    Barthel, Stephan
    Stockholm Resilience Centre, Stockholm University, Stockholm, Sweden; Beijer Institute of Ecological Economics, Stockholm, Sweden.
    Andersson, Erik
    Department of Systems Ecology, Stockholm University, Stockholm, Sweden; Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Uppsala, Sweden .
    Borgström, Sara
    Department of Systems Ecology, Stockholm University, Stockholm, Sweden.
    Scale-Crossing Brokers and Network Governance of Urban Ecosystem Services: The Case of Stockholm2010In: Ecology & society, ISSN 1708-3087, E-ISSN 1708-3087, Vol. 15, no 4, article id 28Article in journal (Refereed)
    Abstract [en]

    Urban ecosystem services are crucial for human well-being and the livability of cities. A central challenge for sustaining ecosystem services lies in addressing scale mismatches between ecological processes on one hand, and social processes of governance on the other. This article synthesizes a set of case studies from urban green areas in Stockholm, Sweden—allotment gardens, urban parks, cemeteries and protected areas—and discusses how governmental agencies and civil society groups engaged in urban green area management can be linked through social networks so as to better match spatial scales of ecosystem processes. The article develops a framework that combines ecological scales with social network structure, with the latter being taken as the patterns of interaction between actor groups. Based on this framework, the article (1) assesses current ecosystem governance, and (2) develops a theoretical understanding of how social network structure influences ecosystem governance and how certain actors can work as agents to promote beneficial network structures. The main results show that the mesoscale of what is conceptualized as city scale green networks (i.e., functionally interconnected local green areas) is not addressed by any actor in Stockholm, and that the management practices of civil society groups engaged in local ecosystem management play a crucial but neglected role in upholding ecosystem services. The article proposes an alternative network structure and discusses the role of midscale managers (for improving ecological functioning) and scale-crossing brokers (engaged in practices to connect actors across ecological scales). Dilemmas, strategies, and practices for establishing this governance system are discussed.

  • 21.
    Finér, L.
    et al.
    Joensuu Research Unit, Finnish Forest Research Institute, Finland.
    Helmisaari, H.-S.
    Vantaa Research Unit, Finnish Forest Research Institute, Finland.
    Lohmus, K.
    Institute of Geography, Tartu University, Estonia.
    Majdi, Hooshang
    Department of Ecology, Swedish University of Agricultural Sciences, Sweden.
    Brunner, I.
    Swiss Federal Institute for Forest, Snow and Landscape Research, Switzerland.
    Borja, I.
    Norwegian Forest and Landscape Institute, Norway.
    Eldhuset, T.
    Norwegian Forest and Landscape Institute, Norway.
    Godbold, D.
    School of Environment and Natural Resources, University of Wales, UK.
    Grebenc, T.
    Slovenian Forestry Institute, Slovenia.
    Konopka, B.
    National Forest Centre, Forest Research Institute Zvolen T. G. Masaryka 22, Slovak Republic.
    Kraigher, H.
    Slovenian Forestry Institute, Slovenia.
    Möttönen, M.-R.
    Faculty of Forestry, University of Joensuu, Finland.
    Ohashi, M.
    School of Human Science and Environment, University of Hyogo, Japan.
    Oleksyn, J.
    Institute of Dendrology, Polish Academy of Sciences, Poland.
    Ostonen, I.
    Institute of Geography, Tartu University, Estonia.
    Uri, V.
    Institute of Forestry and Rural Engineering, Estonian University of Life Sciences, Estonia.
    Vanguelova, E.
    Environmental and Human Science Division, Forest Research, UK.
    Variation in fine root biomass of three European tree species: Beech (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.)2007In: Plant Biosystems, ISSN 1126-3504, E-ISSN 1724-5575, Vol. 141, no 3, p. 394-405Article in journal (Refereed)
    Abstract [en]

    Fine roots (< 2 mm) are very dynamic and play a key role in forest ecosystem carbon and nutrient cycling and accumulation. We reviewed root biomass data of three main European tree species European beech, (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.), in order to identify the differences between species, and within and between vegetation zones, and to show the relationships between root biomass and the climatic, site and stand factors. The collected literature consisted of data from 36 beech, 71 spruce and 43 pine stands. The mean fine root biomass of beech was 389 g m(-2), and that of spruce and pine 297 g m(-2) and 277 g m(-2), respectively. Data from pine stands supported the hypothesis that: root biomass is higher in the temperate than in the boreal zone. The results indicated that the root biomass of deciduous trees is higher than that of conifers. The correlations between root biomass and site fertility characteristics seemed to be species specific. There was no correlation between soil acidity and root biomass. Beech fine root. biomass decreased with stand age whereas pine root biomass increased with stand age. Fine root biomass at tree level. correlated better than stand level root biomass with stand characteristics. The results showed that there exists a strong relationship between the fine root biomass and the above-ground biomass.

  • 22.
    Folke, Carl
    et al.
    Department of Systems Ecology, Stockholm University, Stockholm, Sweden; Centre for Research on Natural Resources and the Environment, Stockholm University, Stockholm, Sweden; Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Berkes, Fikret
    Natural Resources Institute, University of Manitoba, Winnipeg, Canada.
    Colding, Johan
    Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden; Department of Systems Ecology, Stockholm University, Stockholm, Sweden.
    Ecological practices and social mechanisms for building resilience and sustainability1998In: Linking social and ecological systems: Institutional learning for resilience / [ed] Berkes, F. and Folke, C., Cambridge: Cambridge University Press, 1998, 1, p. 414-437Chapter in book (Refereed)
  • 23.
    Folke, Carl
    et al.
    Royal Swedish Academy of Sciences, Stockholm, Sweden; Stockholm University, Stockholm, Sweden.
    Pritchard Jr., L.
    Evangelical Environmental Network, United States.
    Berkes, F.
    University of Manitoba, Winnipeg, MB, Canada.
    Colding, Johan
    Royal Swedish Academy of Sciences, Stockholm, Sweden; Stockholm University, Stockholm, Sweden.
    Svedin, U.
    Swedish Research Council for the Environment, Sweden.
    The problem of fit between ecosystems and institutions: ten years later2007In: Ecology & society, ISSN 1708-3087, E-ISSN 1708-3087, Vol. 12, no 1, article id 30Article in journal (Refereed)
    Abstract [en]

    The problem of fit is about the interplay between the human and ecosystem dimensions in social-ecological systems that are not just linked but truly integrated. This interplay takes place across temporal and spatial scales and institutional and organizational levels in systems that are increasingly being interpreted as complex adaptive systems. In 1997, we were invited to produce one of three background papers related to a, at that time, new initiative called Institutional Dimensions of Global Environmental Change (IDEG), a research activity of the International Human Dimensions Program of Global Environmental Change (IHDP). The paper, which exists as a discussion paper of the IHDP, has generated considerable interest. Here we publish the original paper 10 years later with an extended introduction and with reflections on some of the issues raised in the original paper concerning problems of fit.

  • 24.
    Frank, Jens
    et al.
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences.
    Johansson, Maria
    Environmental Psychology, Dept of Architecture and Built Environment, Lund University.
    Flykt, Anders
    University of Gävle, Faculty of Health and Occupational Studies, Department of Social Work and Psychology, Psychology.
    Public attitude towards the implementation of management actions aimed at reducing human fear of brown bears and wolves2015In: Wildlife Biology, ISSN 0909-6396, E-ISSN 1903-220X, Vol. 21, no 3, p. 122-130Article in journal (Refereed)
    Abstract [en]

    Previous research on human fear of large carnivores has mainly been based on self-reports in which individual survey items and the objects of fear are measured, so whether a person fears attacks on humans or livestock and pets has not been identified. The objectives of this study were to differentiate between the objects of fear as well as capturing attitudes towards implementation of management actions and the potential for conflict index (PCI). These concern the implementation of a limited number of management actions currently used or discussed in Sweden that are aimed at reducing human fear of brown bears/wolves. 391 persons living in areas with either brown bear (n = 198) or wolf (n = 193) in Sweden responded to a questionnaire. The degree of self-reported fear varied between residents in brown bear areas and residents in wolf areas. The fear of attacks on livestock and pets was stronger than fear of attacks on humans in both brown bear and wolf areas. In brown bear areas, fear was strongest for livestock, while in wolf areas fear was strongest for pets. The fear of attacks on livestock and pets was significantly stronger in wolf areas, while the fear of attacks on humans was strongest in brown bear areas. In both brown bear and wolf areas, there was little acceptance of implementation of management actions that would allow people to carry pepper spray or a gun outdoors. Management actions aimed at setting a population cap for bear/wolf populations, information on how to act when encountering a bear/wolf, and providing information on local presence of bear/wolf had relatively high acceptability. This was especially true for respondents expressing high fear of attacks on humans. 

  • 25. Hill, Cathy
    et al.
    Wallström, Kerstin
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    The Stockholm archipelago2008In: Ecology of Baltic coastal waters, Berlin: Springer , 2008Chapter in book (Other academic)
    Abstract [en]

    Stockholm archipelago is the largest connected archipelago in Swedish waters, and extends 200 km along the east coast. It is about 100 km wide off the city of Stockholm. The topography includes valleys, cliffs and rifts. The many biotopes, including open waters, rocky coasts, narrow fjord-like bays and sheltered inlets, house a rich flora and fauna. We describe the pelagic and benthic communities and the environmental status of Stockholm archipelago. The inner archipelago has suffered from severe eutrophication for most of the 20th Century. Nutrient levels are still high but declining, and environmental conditions have gradually improved in the pelagic zone during the last 10-20 years. The sediments have been heavily contaminated by metals and organic pollutants since the early 1900s, especially in the inner archipelago. Concentrations of these pollutants peaked around 1960-1980, but have declined since then.

  • 26.
    Hillström, Lars
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Gieg, Jennifer
    Lyon, Robert
    Siblicidal behavior in relation to food supply in the Cattle egret Bubulcus ibis: an experimental test of the food amount hypothesis2006In: Symposium number: 06, 2006Conference paper (Other (popular science, discussion, etc.))
  • 27.
    Hillström, Lars
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Kilpi, Mikael
    Department of Ecology and Systematics, Zoological Laboratory, Helsinki University, 00014 Helsinki, Finland, FI.
    Lindström, Kai
    Department of Ecology and Systematics, Zoological Laboratory, Helsinki University, 00014 Helsinki, Finland, FI.
    Is asynchronous hatching adaptive in herring gulls ( Larus argentatus )?2000In: Behavioral Ecology and Sociobiology, ISSN 0340-5443, E-ISSN 1432-0762, Vol. 47, no 5, p. 304-311Article in journal (Refereed)
    Abstract [en]

    Hatching asynchrony commonly induces a size hierarchy among siblings and the resultant competition for food between siblings can often lead to starvation of the smallest chicks within a brood. We created herring gull (Larus argentatus) broods with varying degrees of hatching synchrony by manipulating the timing of incubation while maintaining the originally laid eggs. The degree of hatching asynchrony affected sibling size hierarchy at the time of hatching of the last-hatched ”c-chick.” In unmanipulated broods, there was no disadvantage of being a c-chick. However, when asynchrony was experimentally increased, we found reduced survival of the c-chick only in the exaggerated asynchronous experimental group. The effects were observable only during the first 10 days of chick life. We recorded no cases of the chicks dying of starvation. Furthermore, behavioral observations indicated that there was no sibling competition, and no selective feeding of larger sibs in the study colony. We propose that the observed lower survival rates of c-chicks in exaggerated asynchronous broods resulted from their lesser motor abilities, affecting their chances of escaping predators. Fledging success for the whole colony was generally high and almost half of all pairs fledged all three chicks, which is indicative of a good feeding environment. We argue that normal hatching asynchrony is a favorable solution in a good feeding environment, but that increased asynchrony reduces breeding success. We do not view asynchrony in the herring gull as an adaptation for brood reduction and propose instead that it may come about because there has been selection for incubation to start before clutch completion.

  • 28.
    Hillström, Lars
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences, Biology.
    Österdal, Henrik
    Norränge Skog & Natur AB, Norrängevägen 57, 820 10 ARBRÅ.
    Evolution of antlers in the moose Alces alces: a comparison of two different populations in Sweden2010Conference paper (Other academic)
    Abstract [en]

    The Swedish moose population has during the last 60 years been going through rather drastic changes in numbers. Recently there also seemed to have been a shift towards males with less and less developed antlers, which is an important problem for the moose population breeding. The aim with the present study was to study how antler size in the moose is related to age, body mass and population density. Information on the antler and body mass characters was obtained from 425 males that were shot during the annual moose hunting in October between the years 1999-2006. Age and body mass were the variables that explained most of the variation in antler size in this study. A residual of antler points over age, demonstrated a positive correlation between residuals and carcass, such that males with larger antlers for their age, was on average heavier than other males. There was also a significant negative correlation between population density and carcass. The high mortality rate of older males have lead to that few males reach an age where the horns are fully developed and the age distribution has moved to younger ages. As a consequence of this fact the males start to reproduce at younger ages. As the rutting behaviour is a very energy demanding activity, the younger male’s body growth will be constrained and there will be a large cost to come in rutting stage early. As the percentage of males and male age is having an impact on the reproduction of the population, this is an important problem which should be considered in order to give the right prerequisites for a more productive population of moose with big males that have well developed horns.

  • 29.
    Hougner, Cajsa
    et al.
    Department of Economics, Stockholm University, Stockholm, Sweden.
    Colding, Johan
    Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Söderqvist, Tore
    Beijer International Institute of Ecological Economics, Royal Swedish Academy of Sciences, Stockholm, Sweden.
    Economic valuation of a seed dispersal service in the Stockholm National Urban Park, Sweden2006In: Ecological Economics, ISSN 0921-8009, E-ISSN 1873-6106, Vol. 59, no 3, p. 364-374Article in journal (Refereed)
    Abstract [en]

    Most economic valuation studies of species derive from stated preferences methods. These methods fail to take into account biodiversity values that the general public is not (made) informed about or has no experience with. Hence, production function (PF) and replacement cost (RC) approaches to valuation may be preferable in situations where species perform key life support functions in ecosystems, such as seed dispersal, pollination, or pest regulation. We conduct an RC analysis of the seed dispersal service performed by the Eurasian jay (Garrulus glandarius) in the Stockholm National Urban Park, Sweden. The park holds one of the largest populations of giant oaks in Europe, and the oak (Quercus robur and Quercus petrea) represents a keystone species in the hemiboreal forests. The primary objective was to estimate the number of seed-dispersed oak trees that resulted from jays and to determine the costs of replacing this service though human means. Results show that depending upon seeding or planting technique chosen, the RC per pair of jays in the park is SEK 35,000 (USD 4900) and SEK 160,000 (USD 22,500), respectively. Based on the park's aggregated oak forest-area, average RC for natural oak forest regeneration by jays is SEK 15,000 (USD 2100) to SEK 67,000 (USD 9400) per hectare, respectively. These estimates help motivating investments in management strategies that secure critical breeding and foraging habitats of jays, including coniferous forests and jay movement corridors. The analysis also illustrates the need for detailed ecological-economic knowledge in a PF or RC analysis. The continuous temporal and spatial oak dispersal service provided by jays holds several benefits compared to a man-made replacement of this service. PF and RC approaches are particularly motivated in cases of known functional ecological relationships, and critically important in estimating management measures where mobile link organisms and keystone species form key mutual relationships that generate high biodiversity benefits. In relation to obtained results, we discuss insights for conducting valuation studies on particular species.

  • 30.
    Kivimäki, Maarit
    et al.
    Finnish Forest Research Institute, Vantaa Research Unit, Finland; Population Genetics Graduate School, Department of Biology, University of Oulu, Finland.
    Kärkkäinen, Katri
    Finnish Forest Research Institute, Vantaa Research Unit, Finland.
    Gaudeul, Myriam
    Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden; Département Systématique et Evolution, Museum National d’Histoire Naturelle, Paris, France.
    Løe, Geir
    Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Agren, Jon
    Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Gene, phenotype and function: GLABROUS1 and resistance to herbivory in natural populations of Arabidopsis lyrata2007In: Molecular Ecology, ISSN 0962-1083, E-ISSN 1365-294X, Vol. 16, no 2, p. 453-462Article in journal (Refereed)
    Abstract [en]

    The molecular genetic basis of adaptive variation is of fundamental importance for evolutionary dynamics, but is still poorly known. Only in very few cases has the relationship between genetic variation at the molecular level, phenotype and function been established in natural populations. We examined the functional significance and genetic basis of a polymorphism in production of leaf hairs, trichomes, in the perennial herb Arabidopsis lyrata. Earlier studies suggested that trichome production is subject to divergent selection. Here we show that the production of trichomes is correlated with reduced damage from insect herbivores in natural populations, and using statistical methods developed for medical genetics we document an association between loss of trichome production and mutations in the regulatory gene GLABROUS1. Sequence data suggest that independent mutations in this regulatory gene have provided the basis for parallel evolution of reduced resistance to insect herbivores in different populations of A. lyrata and in the closely related Arabidopsis thaliana. The results show that candidate genes identified in model organisms provide a valuable starting point for analysis of the genetic basis of phenotypic variation in natural populations.

  • 31.
    Lindqvist, Camilla
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Tambins inverkan på naturligt förekommande pollinatörer2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is about the impact of honeybees on native pollinators. My questions concerns: availability of food, the health and population level of native pollinators in relation to the presence of honeybees. What has emerged from this literature review is that the introduction of honeybees lead to a decline in numbers of bee and bumblebee pollinators in proximity of the hives and also alters their behaviour, some species choose to forage on other flowers, or later in the day than before honeybees where introduced. The reduced availability of food that this competition induces has a negative impact on the size of bumblebees body’s and thus their survival. What was also discovered was that honeybees can transfer pathogens such as varroa mites, the microsporidium Nosema ceranae and deformed wing virus to bumblebees, leading to reduced life expectancy and poor propagation.

  • 32.
    Løe, Geir
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Herbivore-mediated selection on trichome-production in the perennial herb Arabidopsis lyrata2008Conference paper (Other academic)
    Abstract [en]

    The evolution of a wide range of morphological and physiological characters in plants is believed to have been driven by interactions with insect herbivores. Yet, the effects of insect herbivory on population dynamics and evolutionary trajectories of putative defence traits in natural plant populations are little known. Leaf hairs, trichomes, can reduce herbivore damage, but may also contribute to tolerance against drought and UV-radiation. We conducted a four-year field experiment to determine whether insect herbivory reduces population growth and affects selection on trichome production in a natural population of the outcrossing, perennial herb Arabidopsis lyrata, which is polymorphic for trichome production and occurs in a glabrous and a trichome-producing form. In control plots, glabrous plants were more damaged by insect herbivores and had a lower population growth rate than trichome-producing plants due to a lower probability of remaining in the reproductive stage. Herbivore removal increased population growth rate, in particular in the glabrous morph. In plots from which insect herbivores had been removed, glabrous and trichome-producing plants had similar growth rates. Herbivore removal enhanced the growth rate of the glabrous morph mainly through increasing the probability of remaining in the reproductive stage, and in the trichome-producing morph mainly through increasing the probability for vegetative plants to enter the reproductive stage. The results show that insect herbivory may reduce population growth and result in selection for trichome production in A. lyrata. Spatial and temporal variation in insect herbivory could thus contribute to the maintenance of the polymorphism in trichome production.

  • 33.
    Løe, Geir
    et al.
    Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Toräng, Per
    Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Gaudeul, Myriam
    Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden; Dépt. Systématique et Evolution, Museum National d’Histoire Naturelle, Paris, France.
    Ågren, Jon
    Department of Plant Ecology, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden.
    Trichome-production and spatiotemporal variation in herbivory in the perennial herb Arabidopsis lyrata2007In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 116, no 1, p. 134-142Article in journal (Refereed)
    Abstract [en]

    Allocation theory suggests that the optimal level of resistance against herbivores should vary with the risk of herbivory if allocation to resistance is costly. The perennial herb Arabidopsis lyrata has a genetically based polymorphism for trichome production and occurs in a glabrous and a trichome-producing form. Leaf trichomes (hairs) can protect plants against insect herbivores, and may increase tolerance to drought and UV-radiation. To examine the functional significance of trichome production, we documented the frequency of glabrous plants and damage by insect herbivores in 30 A. lyrata populations in Sweden and Norway. The proportion of glabrous plants ranged from 0.10 to 0.71 (median=0.44) in polymorphic populations; 7 of 12 populations in Norway and 14 of 18 populations in Sweden were monomorphic glabrous, i.e. with fewer than 5% trichome-producing plants. The mean proportion of the leaf area removed by herbivores varied substantially among populations and years. With few exceptions, glabrous plants were more damaged than trichome-producing plants in polymorphic populations. The intensity of herbivory quantified as the mean damage to glabrous plants tended to be higher in polymorphic populations than in populations monomorphic for the glabrous morph and was higher in Sweden than in Norway. In Norway, both the magnitude of herbivore damage and the frequency of trichome-producing plants tended to decrease with increasing altitude. The results indicate that leaf trichomes contribute to resistance against herbivorous insects in A. lyrata, and suggest that herbivore-mediated selection contributes to the maintenance of the polymorphism in trichome production.

  • 34.
    Majdi, Hooshang
    Swedish University of Agricultural Sciences, Department of Ecology, Uppsala, Sweden.
    Root and root-lignin degradation in a Norway spruce stand: effects of long-term nitrogen addition2007In: Plant Biosystems, ISSN 1126-3504, E-ISSN 1724-5575, Vol. 141, no 2, p. 214-221Article in journal (Refereed)
    Abstract [en]

    Mass loss, degradation of lignin and the qualitative change of the organic C structures of spruce root litter (2-5 mm in diameter) in O-horizon were studied for a period of 6 years (1995-2001) in a Norway spruce stand with a current deposition of 13 kg N and 12 kg S ha(-1) yr(-1). The stand was fertilized annually by addition of 100 kg N and 114 kg S ha(-1) (NS). Litterbags, acid detergent lignin (ADL), CuO-oxidation as well as C-13-NMR were used for measurements of mass loss, lignin concentration, degradation of lignin and changes of the organic C structures, respectively. The roots originating from the NS-treated plots lost 20% of their mass in the first year while in control (CON) plots the corresponding value was 10%. After 1879 days of decomposition the fertilized roots had a cumulative mass loss of 54% compared with the CON roots of 44%. The C/N ratios were significantly lower in the NS roots (35) than in the CON roots (59) after 1879 days of decomposition. The initial concentrations of ADL were 34.7 and 36.6 in CON and NS roots and increased to 50 and 56%, respectively, after 1879 days. Using CuO-oxidation method the degree of lignin degradation was significantly higher in the NS than CON roots after 853 days while C-13 NMR method showed no change. Our results indicate that CuO-oxidation and solid-state C-13 NMR methods give a qualitative measure of lignin decomposition, while the litterbag and ADL methods allow us to quantify mass loss and lignin concentration, respectively. It is concluded that the mass loss of root litter in fertilized plots is higher than needle litter decomposition in the same stand and the higher nitrogen concentration increases the lignin degradation.

  • 35.
    Majdi, Hooshang
    et al.
    Departments of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Nylund, Jan-Erik
    Forest Products and Markets, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Ågren, Göran I.
    Departments of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Root respiration data and minirhizotron observations conflict with root turnover estimates from sequential soil coring2007In: Scandinavian Journal of Forest Research, ISSN 0282-7581, E-ISSN 1651-1891, Vol. 22, no 4, p. 299-303Article in journal (Refereed)
    Abstract [en]

    The turnover of fine roots in northern coniferous forests has conventionally been assumed to be rapid, in line with results from sequential coring in the late 1970s in a Swedish Scots pine stand (SWECON project) where a rate of 7.4 year(-1) was estimated. New quantifications of the root respiration in other stands motivated a recalculation of the SWECON data; an indirect estimation of the turnover rate was much slower, about 2.1 year(-1). As a consequence, fine-root production is considered to be much lower than in previous estimates. Furthermore, direct observations of Norway spruce fine roots (< 1 mm) from minirhizotrons in Sweden, including a site close to the SWECON site, indicated a slower estimate, with fine-root turnover rate of 0.9 year

  • 36.
    Majdi, Hooshang
    et al.
    Departments of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Nylund, JE
    Forest Products and Markets, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Ågren, Göran I.
    Departments of Ecology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
    Response to comments on 'Root respiration data and minirhizotron observations conflict with root turnover estimates from sequential soil coring'2007In: Scandinavian Journal of Forest Research, ISSN 0282-7581, E-ISSN 1651-1891, Vol. 22, no 6, p. 473-474Article in journal (Refereed)
  • 37.
    Mattsson, Jan-Eric
    et al.
    Södertörns högskola, Biologi.
    Vinter, Tiina
    Södertörns högskola, Institutionen för livsvetenskaper.
    Lönn, Mikael
    Södertörns högskola, Institutionen för livsvetenskaper.
    Macrolichen diversity in relation to diversity of woody plants2006Conference paper (Other academic)
    Abstract [en]

    In studies concerning nature conservation issues common lichen species have usually been neglected although collecting of these results gives comparatively small disturbance of the populations and is easily done. Instead rare or threatened species or species usually have been used as indicators of sites with high biodiversity. Here, the macrolichen diversity is compared with the diversity of woody plants and other characteristics of different sites in Estonia, Finland and Sweden as a part of a larger project including comparative studies on habitats with presumably high species diversity The site selection was based on the occurrence of Daphne mezereum which usually occurs in semi-open habitats in transitions zones containing species from the surrounding biotopes. One of the main objectives with the study was to develop a fairly rapid method of evaluation of biodiversity using easily identified species. As total inventories are time consuming and reflects snapshots of a certain occasion it is beneficial to use other methods which may give a little less but sufficient information for many purposes, e.g., estimations on biodiversity. The ecological and evolutionary processes that shape diversity and distributions are general and results are assumed to be translatable from the target species to other species. The combination of data from a small number of species may constitute a useful monitoring protocol for lichens and higher plants. In total about 50 lichen species and 25 substrates are included and analyzed in the study. Most of the most common lichens are sorediate or isidiate and asexually reproducing and occur on several substrates. The relation between the diversity of lichen and woody plants is presented.

  • 38.
    Niva, Sanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Parkers potential för gynnande av humlor i urbana miljöer2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is dealing with how existing parks in urban areas can fill a bigger role for bumblebees then they are today. My questions concern: lack of food for bumblebees in parks, lack of opportunities to find places to live and to hibernate and actions how to mitigate this. The results of this study show that existing parks can have a bigger positive impact on the biodiversity in urban areas. If bumblebees can’t find places to live or hibernate or find food, the risk is then that their populations will continue to decline which will have a strongly negative effect on us humans because we are depending on pollinators. With the right knowledge and measures we can make it easier for bumblebees to live in urban areas. To facilitate for biodiversity in the planning of parks means that we will create oases which both humans, birds and insects can benefit from.

  • 39.
    Ostonen, I.
    et al.
    Institute of Geography, University of Tartu, Estonia.
    Püttsepp, Ü.
    Department of Ecology, Swedish University of Agricultural Sciences, Sweden; Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Estonia.
    Biel, C.
    RTA, Departament d’Horticultura Ambiental, Carretera de Cabrils, Spain.
    Alberton, O.
    Department of Soil Quality, Wageningen University, The Netherlands.
    Bakker, M.R.
    ENITA de Bordeaux, UMR 1220 TCEM (INRA-ENITAB), France.
    Lohmus, K.
    Institute of Geography, University of Tartu, Estonia.
    Majdi, Hooshang
    Department of Ecology, Swedish University of Agricultural Sciences, Sweden.
    Metcalfe, D.
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Sweden.
    Olsthoorn, A.F.M.
    Van Hall Larenstein University of Professional Education, The Netherlands.
    Pronk, A.
    Plant Research International, Wageningen University and Research Centre, The Netherlands.
    Vanguelova, A.
    Environmental & Human Sciences Division, Forest Research, UK.
    Weih, M.
    Department of Crop Production Ecology, Swedish University of Agricultural Sciences, Sweden.
    Brunner, I.
    Swiss Federal Institute for Forest, Snow and Landscape Research, Switzerland.
    Specific root length as an indicator of environmental change2007In: Plant Biosystems, ISSN 1126-3504, E-ISSN 1724-5575, Vol. 141, no 3, p. 426-442Article in journal (Refereed)
    Abstract [en]

    Specific root length (SRL, m g(-1)) is probably the most frequently measured morphological parameter of fine roots. It is believed to characterize economic aspects of the root system and to be indicative of environmental changes. The main objectives of this paper were to review and summarize the published SRL data for different tree species throughout Europe and to assess SRL under varying environmental conditions. Meta-analysis was used to summarize the response of SRL to the following manipulated environmental conditions: fertilization, irrigation, elevated temperature, elevated CO(2), Al-stress, reduced light, heavy metal stress and physical disturbance of soil. SRL was found to be strongly dependent on the fine root classes, i.e. on the ectomycorrhizal short roots (ECM), and on the roots < 0.5 mm, < 1 mm, < 2 mm and 1-2 mm in diameter SRL was largest for ECM and decreased with increasing diameter. Changes in soil factors influenced most strongly the SRL of ECM and roots < 0.5 mm. The variation in the SRL components, root diameter and root tissue density, and their impact on the SRL value were computed. Meta-analyses showed that SRL decreased significantly under fertilization and Al-stress; it responded negatively to reduced light, elevated temperature and CO(2). We suggest that SRL can be used successfully as an indicator of nutrient availability to trees in experimental conditions.

  • 40. Pasanen-Mortensen, Marianne
    et al.
    Pyykönen, Markku
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Urban and regional planning/GIS-institute.
    Elmhagen, Bodil
    Where lynx prevail, foxes will fail: limitation of a mesopredator in Eurasia2013In: Global Ecology and Biogeography, ISSN 1466-822X, E-ISSN 1466-8238, Vol. 22, no 7, p. 868-877Article in journal (Refereed)
    Abstract [en]

    Aim Climate change and loss of apex predators can affect ecosystem structure and function through modified limitation processes. We investigated, on a continental scale, whether mesopredator abundance is limited from the top down by large predators, as predicted by the mesopredator release hypothesis, or by bottom-up factors. The mesopredator in focus is the red fox Vulpes vulpes, a key predator in many ecosystems due to its strong effects on prey abundance. Location Europe and northern Asia. Methods Data on red fox density were compiled from published papers and reports. For each site, we collated presence-absence data on large carnivores (Lynx lynx, Canis lupus, Canisaureus) and remote sensing data for factors potentially related to bottom-up limitation (winter severity, summer temperature, human density, primary productivity, tree cover). The data were analysed through structural equation modelling. Results The presence of lynx had a direct negative effect on red foxes, suppressing fox abundance. Also winter severity had a negative effect on red fox abundance, and in Eurasia as a whole this effect was partially mediated through lynx. Within the lynx distribution range, winter severity was the only bottom-up factor significantly affecting red fox abundance. Outside the lynx distribution range, primary productivity, summer temperature and human density had a positive effect on red fox abundance. Main conclusions Our results show that apex predators can limit mesopredator abundance on a continental scale, thus supporting the mesopredator release hypothesis. Winter severity also affected red fox abundance, partially due to an interaction between lynx and winter conditions. On the continental scale a complex network of processes operates with varying effects depending on mediation processes. Our results imply that apex predators can have an important effect on ecosystem structure by limiting mesopredator abundance, and we suggest that apex predators may dampen increases in mesopredator abundance driven by global warming.

  • 41.
    Sanchez Tortosa, Francisco
    et al.
    Departamento de Biología Animal, Edificio C-1, Campus de Rabanales, Universidad de Córdoba, 14071.
    Pérez, Lorenzo
    Departamento de Biología Animal, Edificio C-1, Campus de Rabanales, Universidad de Córdoba, 14071.
    Hillström, Lars
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Effect of food abundance on laying date and clutch size in the White Stork Ciconia ciconia2003In: Bird Study, ISSN 0006-3657, E-ISSN 1944-6705, Vol. 50, p. 112-115Article in journal (Refereed)
    Abstract [en]

    Capsule- Food independently affects both laying date and clutch size, suggesting that seasonal decline in clutch size is related to a decrease in food availability.

    Aim - To test the effect of food abundance on laying date and clutch size of the White Stork and identify the cause of seasonal decline in the number of eggs laid.

    Methods - During 1991 and 1996 we recorded clutch size and laying date of pairs breeding next to rubbish dumps (food abundant and constant throughout the breeding season) and birds breeding far from rubbish dumps (using natural food sources).

    Results - In 1991 there was no difference in mean laying date between pairs nesting at rubbish dumps and control pairs. Clutch size was significantly larger at rubbish dump nests. In contrast, mean laying date was earlier in control pairs in 1996 and there was no significant differences in clutch sizes, even when controlling for laying date effect.

    Conclusion - The results support the hypothesis that food availability independently affects both laying date and clutch size. The seasonal decline in clutch size close to rubbish dumps was negligible (1991) or much smaller than in the control zone (1996) suggesting that a progressive deterioration of natural food sources is the most probable reason for a decline in clutch size as the season advances.

  • 42.
    Sinclair, Paul
    et al.
    Uppsala universitet.
    Isendahl, Christian
    Göteborgs universitet.
    Barthel, Stephan
    Stockholm Resilience Centre (SRC), Stockholms universitet.
    Beyond Rhetoric: Towards a Framework for an Applied Historical Ecology of Urban Planning2016In: The Oxford Handbook of Historical Ecology and Applied Archaeology / [ed] Christian Isendahl and Daryl Stump, Oxford University Press, 2016Chapter in book (Other academic)
    Abstract [en]

    Historical ecological approaches to settlement aggregation and complexity reject modernist and post-modernist reliance on linear neo-evolutionary categorization of cities in relation to earlier farming communities. Instead, urban centres and multi-urban systems are viewed as components of complex heterarchically and hierarchically organized landscapes. Resilience theory has been applied in several archaeological efforts to characterize urban development of specific centres. Building on experience from the recently concluded Urban Mind project this chapter argues for a historical ecology approach to track the long-term cultural and environmental dynamics of multi-centred urban systems. Linking human cognition, social memory, ecosystem services, urban metabolism and food security, and institutions of urban governance, it uses data on long-term urban histories in the eastern Mediterranean, southern Africa, and Mesoamerica to identify implications for future urban planning initiatives.

  • 43. Strokirch, Svante von
    et al.
    Wallström, Kerstin
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Botanisk mångfald i Lövstabukten2008In: Svensk Botanisk Tidskrift, ISSN 0039-646X, Vol. 102, no 3-4, p. 135-146Article in journal (Other academic)
    Abstract [en]

    The bay of Lövstabukten is located in northern Uppland, E Sweden. Land uplift is c. 6 mm per year and strongly influences the landscape, giving rise to expanding seashores and the gradual transformation of shallow water bodies into lakes. The various habitats that are formed give rise to a diversified flora. The vegetation is also favoured by the calcareous moraine. We describe the plant communities on the shores and on soft bottoms in the bay. Several notable species have been found of which 13 are redlisted. It is notable that all 9 charophytes that have been found in the Bothnian Sea are present in Lövstabukten. We conclude that because of its high natural values, the Lövstabukten area must be protected.

  • 44.
    Wahlqvist, Hanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Electronics, Mathematics and Natural Sciences.
    Kransalgers förekomst i ett historiskt perspektiv i fem närliggande gloflador2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 45.
    Åhman, Fredrik
    et al.
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för datavetenskap.
    Hillström, Lars
    University of Gävle, Department of Mathematics, Natural and Computer Sciences, Ämnesavdelningen för naturvetenskap.
    Using a Game Theoretical Approach for Experimental Simulation of Brood Reduction: Conflict and Co-Operation, Effect on Brood Size with Limited Resources2005In: Proceedings of the Seventh International Conference on Enterprise Information Systems, 2005, p. 220-225Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    The evolution of parental care includes typical caring behaviour, such as protecting or feeding offspring. Sibling rivalry is anthropogenic viewed as conflicting behaviour, and can ultimately lead to brood reduction. In this study we have used object oriented programming to simulate different scenarios in this sibling rivalry conflict. A number of hypotheses have been proposed to explain the complex interactions occurring during brood reduction, but few simulation models successfully combines it with a hypothesis necessary to describe an ESS. In our solution we present a simple experimental simulation for brood reduction, where each sibling acts as an autonomous agent that has the ability to initiate actions for cooperation and competition against other siblings. Agents have a limited set of actions that can be activated during the onset of some specific environmental conditions, such as prey density, different climate variables etc. Parameters for food distribution are determined on a basis of a former known theory for maximizing inclusive fitness. In the computer simulations we have studied effects on sizes of siblings and fitness measures with varying degree of hatching patterns and prey density for siblings within the artificial brood. Results from the experimental simulations demonstrate interesting similarities with brood reduction in a real world setting, such as in raptorial birds that practice facultative siblicidal behaviour. Agents within the artificial brood respond with stronger conflicting behaviour whenever resources are limited and simulating increased hatching asynchrony lead to a lower survival rate (because of increased size hierarchy) of siblings within the simulated brood.

1 - 45 of 45
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard-cite-them-right
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • sv-SE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • de-DE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf