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  • 1.
    Johansson, Sverker
    Högskolan i Jönköping, Högskolan för lärande och kommunikation.
    What constraints does animal communication place on human language origins?2010Konferansepaper (Annet vitenskapelig)
  • 2.
    Nyberg, Roger G.
    et al.
    Högskolan Dalarna, Akademin Industri och samhälle, Datateknik. School of Engineering and the Built Environment, Edinburgh Napier University, EH10 5DT Edinburgh, UK.
    Gupta, Narendra K.
    School of Engineering and the Built Environment, Edinburgh Napier University, EH10 5DT Edinburgh, UK.
    Yella, Siril
    Högskolan Dalarna, Akademin Industri och samhälle, Datateknik.
    Dougherty, Mark
    Högskolan Dalarna, Akademin Industri och samhälle, Datateknik.
    Monitoring vegetation on railway embankments: supporting maintenance decisions2013Inngår i: Proceedings of the 2013 International Conference on Ecology and Transportation, 2013, s. 1-18Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The national railway administrations in Scandinavia, Germany, and Austria mainly resort to manual inspections to control vegetation growth along railway embankments. Manually inspecting railways is slow and time consuming. A more worrying aspect concerns the fact that human observers are often unable to estimate the true cover of vegetation on railway embankments. Further human observers often tend to disagree with each other when more than one observer is engaged for inspection. Lack of proper techniques to identify the true cover of vegetation even result in the excess usage of herbicides; seriously harming the environment and threating the ecology. Hence work in this study has investigated aspects relevant to human variationand agreement to be able to report better inspection routines. This was studied by mainly carrying out two separate yet relevant investigations.First, thirteen observers were separately asked to estimate the vegetation cover in nine imagesacquired (in nadir view) over the railway tracks. All such estimates were compared relatively and an analysis of variance resulted in a significant difference on the observers’ cover estimates (p<0.05). Bearing in difference between the observers, a second follow-up field-study on the railway tracks was initiated and properly investigated. Two railway segments (strata) representingdifferent levels of vegetationwere carefully selected. Five sample plots (each covering an area of one-by-one meter) were randomizedfrom each stratumalong the rails from the aforementioned segments and ten images were acquired in nadir view. Further three observers (with knowledge in the railway maintenance domain) were separately asked to estimate the plant cover by visually examining theplots. Again an analysis of variance resulted in a significant difference on the observers’ cover estimates (p<0.05) confirming the result from the first investigation.The differences in observations are compared against a computer vision algorithm which detects the "true" cover of vegetation in a given image. The true cover is defined as the amount of greenish pixels in each image as detected by the computer vision algorithm. Results achieved through comparison strongly indicate that inconsistency is prevalent among the estimates reported by the observers. Hence, an automated approach reporting the use of computer vision is suggested, thus transferring the manual inspections into objective monitored inspections

  • 3. Olsson, E. G. A.
    et al.
    Maad, Johanne
    Högskolan Dalarna, Akademin Utbildning, hälsa och samhälle, Naturvetenskap.
    Myklebost, H. E.
    Variation in life history traits of Gentiana nivalis (Gentianaceae) in alpine and sub-alpine habitats in the Norwegian mountains and its implications for biodiversity in relation to environmental change2015Inngår i: Annales Botanici Fennici, ISSN 0003-3847, E-ISSN 1797-2442, Vol. 52, nr 3-4, s. 149-159Artikkel i tidsskrift (Fagfellevurdert)
  • 4. Sivertsen, Therese R.
    et al.
    Åhman, Birgitta
    Steyaert, Sam M. J. G.
    Rönnegård, Lars
    Högskolan Dalarna, Akademin Industri och samhälle, Statistik.
    Frank, Jens
    Segerström, Peter
    Støen, Ole-Gunnar
    Skarin, Anna
    Reindeer habitat selection under the risk of brown bear predation during calving season2016Inngår i: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 7, nr 11, artikkel-id e01583Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The depredation of semi-domesticated reindeer by large carnivores reflects an important human-wildlife conflict in Fennoscandia. Recent studies have revealed that brown bears (Ursus arctos) may kill substantial numbers of reindeer calves (Rangifer tarandus tarandus) in forest areas in Sweden. Several authors have suggested that predation risk is an important driver of habitat selection in wild Rangifer populations where predation is a limiting factor, but little is known about these mechanisms in semi-domesticated populations. We examined the habitat selection of female reindeer in relation to spatial and temporal variations in brown bear predation risk on the reindeer calving grounds and evaluated the simultaneous responses of brown bears and reindeer to landscape characteristics. We used GPS data from 110 reindeer years (97 individuals) and 29 brown bear years (19 individuals), from two reindeer herding districts in the forest area of northern Sweden. Our results did not indicate that reindeer alter their behavior in response to spatiotemporal variation in brown bear predation risk, on the scale of the calving range. Instead, we suggest that spatiotemporal behavioral adjustments by brown bears were the main driver of prey-predator interactions in our study system. Contrasting responses by brown bears and reindeer to clear-cuts and young forest indicate that forestry can influence species interactions and possibly yield negative consequences for the reindeer herd. Even if clear-cuts may be beneficial in terms of calf survival, logging activity will eventually cause greater abundance of young regenerating forest, reducing available reindeer habitats and increasing habitat preferred by brown bears. Domestication may have made semi-domesticated reindeer in Fennoscandia less adapted to cope with predators. Areal restrictions, limiting the opportunity for dispersion and escape, possibly make the calves more susceptible to predation. Also, a generally higher population density in semi-domesticated herds compared to wild populations can make dispersion a less efficient strategy and the reindeer calves easier prey. Overall, the lack of ability of the reindeer females to reduce brown bear encounter risk on the scale of the calving range is probably an important reason for the high brown bear predation rates on reindeer calves documented in our study areas. 

  • 5. Skarin, Anna
    et al.
    Helleman, Christian
    Sandström, Per
    Rönnegård, Lars
    Högskolan Dalarna, Akademin Industri och samhälle, Statistik.
    Lundquist, Henrik
    Renar och vindkraft: Studie från anläggningen av två vindkraftparker i Malå sameby2013Rapport (Annet vitenskapelig)
    Abstract [sv]

    Studien undersöker hur renar påverkas under konstruktionsfasen när vindkraftverk byggs. Studien följer uppförandet av två nya vindparker i Malå kommun i Västerbotten. Sammanlagt byggdes 18 vindkraftverk i Malå samebys kalvnings- och försommarland. Inventering av renspillning samt positioner från renar med GPS-halsband visar att konstruktionen av vindkraftsparkerna har påverkat renarnas användning av området. Analysen visar att renarna under tiden för byggnationen har sökt sig bort från området. Spillningsinventeringen och GPS-data visar också att renarna undviker kraftledningar och större vägar när de ska beta.

    Rapport från kunskapsprogrammet Vindval.

  • 6.
    Skarin, Anna
    et al.
    Swedish Univ Agr Sci, Dept Anim Nutr & Management, Uppsala.
    Nellemann, Christian
    GRID Arendal, United Nations Environm Programme, Lillehammer, Norway..
    Rönnegård, Lars
    Högskolan Dalarna, Akademin Industri och samhälle, Statistik.
    Sandstrom, Per
    Swedish Univ Agr Sci, Dept Forest Resource Management, Umea, Sweden.
    Lundqvist, Henrik
    Swedish Univ Agr Sci, Dept Anim Nutr & Management, Uppsala, Sweden.
    Wind farm construction impacts reindeer migration and movement corridors2015Inngår i: Landscape Ecology, ISSN 0921-2973, E-ISSN 1572-9761, Vol. 30, nr 8, s. 1527-1540Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Over the last decade, we have seen a massive increase in the construction of wind farms in northern Fennoscandia. Wind farms comprising hundreds of wind turbines are being built, with little knowledge of the possible cumulative adverse effects on the habitat use and migration of semi-domesticated free-ranging reindeer. We assessed how reindeer responded to wind farm construction in an already fragmented landscape, with specific reference to the effects on use of movement corridors and reindeer habitat selection. We used GPS-data from reindeer during calving and post-calving in the MalAyen reindeer herding community in Sweden. We analysed data from the pre-development years compared to the construction years of two relatively small wind farms. During construction of the wind farms, use of original migration routes and movement corridors within 2 km of development declined by 76 %. This decline in use corresponded to an increase in activity of the reindeer measured by increased step lengths within 0-5 km. The step length was highest nearest the development and declining with distance, as animals moved towards migration corridors and turned around or were observed in holding patterns while not crossing. During construction, reindeer avoided the wind farms at both regional and landscape scale of selection. The combined construction activities associated with even a few wind turbines combined with power lines and roads in or close to central movement corridors caused a reduction in the use of such corridors and grazing habitat and increased the fragmentation of the reindeer calving ranges.

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