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  • 1.
    Al Jawaheri, Raad
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Negative impact of lake liming programmes on the species richness of dragonflies (Odonata): a study from southern Sweden2017Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 788, nr 1, s. 99-113Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Liming programmes aiming to restore fish populations are being implemented in many acidified aquatic systems in northern Europe. We studied Odonata communities in 47 forest lakes in SW Sweden, 13 that are currently being limed, and 8 that have previously been limed. Thirty-one species were recorded, with the highest mean number in untreated lakes, followed by previously treated lakes and currently treated lakes. Species communities differed between untreated and limed lakes, but only few rare species found in the untreated lakes were absent in the treated lakes. Likewise, species known to thrive in acid environments were either rare or showed no preferences. Comparing the number of records of odonate species within a large regional area to the proportion of lakes inhabited in our study, we found that seven of the most commonly observed species occurred less frequently in limed lakes than in the untreated ones, including two of the three most common taxa. Reduced species numbers in limed lakes might be due to conditions on other trophic levels, including fish predation. We argue that Odonata should be considered when developing new biological indices of water quality, although the causes of the observed occurrence patterns need to be studied further. © 2016 Springer International Publishing Switzerland

  • 2.
    Andersson, Emma
    Högskolan i Halmstad.
    A study of how fragmentation affects distribution and diversity among Nymphalidae, Papilionidae and Pieridae (Lepidoptera): in native and exotic forest fragments in southern Brazil2015Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
  • 3.
    Andersson, Julia
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Does clearcutting as a method for forestry impact the aquatic life in lakes nearby?2016Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Clearcutting is the most common method for forestry in Sweden. However research shows that this type of intense management can have a negative impact on biological biodiversity as it interferes with an area’s natural characteristics. Previous studies have mainly focused on biological effects on land. In this study dragonflies were used as biological indicators to investigate the impact of clearcutting in aquatic environments. The result from this study indicate that the use of clearcutting as a method for forestry can, with a certain postponement in time, negatively affect the species diversity of Odonata, and thus also the aquatic biodiversity in lakes in the immediate surroundings of a clearcut area, although it is still unclear exactly how and by which mechanisms. It is also uncertain if the effects are only temporarily, or long-term. If Sweden is to reach the environmental goal of Flourishing Lakes and Streams, it is essential to adopt further safety measures when conducting clearcutting near waters to avoid negative impact on the aquatic biological diversity.

  • 4.
    Bartholdsson, David
    Högskolan i Halmstad.
    Den invasiva vresrosens (Rosa rugosa) etablering samt återetablering i de sanddominerade miljöerna i Gullbranna/Tönnersa naturreservat2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Vresrosen, Rosa rugosa, är en kraftigt invasiv art med en oerhörd konkurrenskraft i sanddominerademiljöer såsom sanddyner och sandblottor. Ofta leder etableringen av R. rugosa i dessasanddominerade miljöer till total igenväxning av området med en starkt negativ påverkan på deninhemska floran och faunan. Då merparten av arterna i dessa habitat är beroende av den unika miljönsom den skiftande sanden skapar så innebär igenväxningen ett mycket stort hot. När området bindsupp till en mer stabil miljö utan det permanent tidiga successionsstadium som den vanligtvis befinnersig i så påverkar det även näringsmängden i sanden med ökade näringshalter samt att de varma, öppnamicrositesen försvinner tillsammans med sandens förmåga att röra sig. Eftersom många av deovanliga och hotade arterna kräver en väldigt specifik miljö så försvinner de ofta också närigenväxningen nått så här långt. Denna studie fokuserar på vresrosens etablering och påverkan isanddominerade miljöer. Studien går även in forskning kring samt hur man praktiskt bekämparväxten, då den hotar många ekologiskt viktiga områden. Dessutom hanterar rapporten mina egnaresultat efter inventeringar i Gullbranna/Tönnersa, ett område som historiskt sett varit mycket hårtpåverkat av vresrosen.

  • 5.
    Bergström, Jakob
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Vedlevande Coleoptera och Hemiptera förekomst på öar i Kolsnaren i sydvästra Södermanland2017Självständigt arbete på grundnivå (kandidatexamen), 180 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    SAMMANFATTNING

    Sju öar i Kolsnaren har undersökts. Jag har inventerat vedlevande insekter och undersökt vilka karaktärer på död ved (art, grovlek, rötstadie och solexponering) samt karaktärer på öarna (storlek, avstånd till land, ljusinsläpp, trädarter samt mängden död ved) som påverkar artantalet av skalbaggar (Coleoptera) och halvvingar (Hemiptera). Denna studie visade på ett relativt lågt artantal av skalbaggar och halvvingar men troligen finns det många fler arter, framförallt fler sällsynta liksom hotade arter. Öarnas karaktärer varierade mellan varandra men även på de enskilda öarna var det variationer i form av olika trädarter, grovlek, rötstadier och solexponering av den döda veden. Därför finns det goda förutsättningar för en mängd olika vedlevande arter med varierande habitatkrav att finna lämpligt substrat. Öarna är delvis isolerade av vatten men det utgör inget större hinder för de flesta skalbaggar. Däremot är det viktigt att det finns gott om död ved med varierande karaktärer runt omkring Kolsnaren så att vedlevande skalbaggar får möjlighet att sprida sig och återkolonisera öarna då även habitaten ändras med tiden. Den döda vedens grovlek och rötstadie var de karaktärerna som hade störst inverkan på antalet arter.

  • 6.
    Bonnot, N. C.
    et al.
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, 730 91, Sweden.
    Bergvall, U. A.
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, 730 91, Sweden.
    Jarnemo, Anders
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Kjellander, P.
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, Riddarhyttan, 730 91, Sweden.
    Who’s afraid of the big bad wolf?: Variation in the stress response among personalities and populations in a large wild herbivore2018Ingår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 188, nr 1, s. 85-95Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Faced with rapid environmental changes, individuals may express different magnitude and plasticity in their response to a given stressor. However, little is known about the causes of variation in phenotypic plasticity of the stress response in wild populations. In the present study, we repeatedly captured individual roe deer (Capreolus capreolus) from two wild populations in Sweden exposed to differing levels of predation pressure and measured plasma concentrations of stress-induced cortisol and behavioral docility. While controlling for the marked effects of habituation, we found clear between-population differences in the stress-induced cortisol response. Roe deer living in the area that was recently recolonized by lynx (Lynx lynx) and wolves (Canis lupus) expressed cortisol levels that were around 30% higher than roe deer in the human-dominated landscape free of large carnivores. In addition, for the first time to our knowledge, we investigated the stress-induced cortisol response in free-ranging newborn fawns and found no evidence for hypo-responsiveness during early life in this species. Indeed, stress-induced cortisol levels were of similar magnitude and differed between populations to a similar extent in both neonates and adults. Finally, at an individual level, we found that both cortisol and docility levels were strongly repeatable, and weakly negatively inter-correlated, suggesting that individuals differed consistently in how they respond to a stressor, and supporting the existence of a stress-management syndrome in roe deer. © 2018, The Author(s).

  • 7.
    Brönmark, Christer
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E. B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Indirect effects of fish community structure on submerged vegetation in shallow, eutrophic lakes: an alternative mechanism1992Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 243/244, nr 1, s. 293-301Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The loss of submerged macrophytes during eutrophication of shallow takes is a commonly observed phenomenon. The proximate reason for this decline is a reduction of available light due to increasing phytoplankton and/or epiphyton biomass. Here we argue that the ultimate cause for the transition from a macrophyte-dominated state to a phytoplankton-dominated state is a change in fish community structure. A catastrophic disturbance event (e.g. winterkill) acting selectively on piscivores, cascades down food chains, eventually reducing macrophyte growth through shading by epiphyton, an effect that is reinforced by increasing phytoplankton biomass. The transition back from the phytoplankton to the macrophyte state depends on an increase in piscivore standing stock and a reduction of planktivores. A conceptual model of these mechanisms is presented and supported by literature data and preliminary observations from a field experiment. © 1992 Kluwer Academic Publishers.

  • 8.
    Brönmark, Christer
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Decoupling of cascading trophic interactions in a freshwater, benthic food chain1996Ingår i: Oecologia, ISSN 0029-8549, E-ISSN 1432-1939, Vol. 108, nr 3, s. 534-541Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Food chain theory provides explicit predictions for equilibrium biomasses among trophic levels in food chains of different lengths. Empirical studies on freshwater benthic food chains have typically been performed on chains with up to three levels and in field experiments with limited spatial and temporal scale. Here we use a ‘’natural snapshot experiment” approach to study equilibrium biomass and abundance among trophic levels in natural ponds differing only with respect to fish assemblage structure. Forty-four ponds were surveyed for their density and biomass of fish, snails and periphyton. Ponds were divided into three categories based on fish assemblage: ponds with no fish (two trophic levels), ponds with molluscivorous fish (three trophic levels), ponds with molluscivorous fish (three trophic levels) and ponds that also had piscivorous fish (four trophic levels). Ponds without fish had a high density and biomass of snails and a low biomass of periphyton, whereas snails with molluscivorous fish. In the presence of piscivores, molluscivore populations consisted of low numbers of large individuals. Snail assemblages in piscivore ponds were characterised by relatively high densities of small-bodied detritivorous species and periphyton biomass was not significantly different from ponds with three trophic levels. Thus, predictions from classic food chain theory were upheld in ponds with up to three trophic levels. In ponds with four trophic levels, however, there was a decoupling of the trophic cascade at the piscivore-molluscivore level. Gape-limited piscivory, predation on snails by molluscivores that have reached an absolute size refuge from predation, and changes in food preferences of the dominant snails are suggested to explain the observed patterns.

  • 9.
    Carlzon, Linnéa
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Karlsson, Amanda
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Falk, Knud
    www.vandrefalk.dk, Stockholm, Sweden.
    Liess, Antonia
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Møller, Søren
    Roskilde University Library, Roskilde, Denmark.
    Extreme weather affects Peregrine Falcon (Falco peregrinus tundrius) breeding success in South Greenland2018Ingår i: Ornis Hungarica, ISSN 1215-1610, Vol. 26, nr 2, s. 38-50Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to better understand the potential effects of climate change on the Peregrine Falcon, we investigated the relationship between extreme weather events and Peregrines’ breeding success in South Greenland. We defined three variables – number of days with extremely low temperatures, extreme precipitation, consecutive rainy days – and an additive variable, total days with extreme weather, and tested their relationship with Peregrines’ breeding success (measured as young per site and nest success) over a 33 year study period. Breeding success was negatively influenced by the number of days with extreme weather and extremely low temperature. The strongest relationship found was total days with extreme weather in the entire breeding season, which explained 22% and 27% of the variation in nest success and young per site, respectively. The number of days with extreme weather in our study related to fluctuations in the North Atlantic Oscillation (NAO). Thus, with a strengthening of the NAO, linked to climate change, more extreme weather may occur in the Arctic and induce increased variation in Peregrines’ breeding success. Our data did not allow us to pinpoint when in the breeding cycle inclement weather was particularly harmful, and we recommend finer-scale research (e.g. automated nest cameras) to better monitor the species-specific effects of rapidly changing climate.

  • 10.
    David, M.
    et al.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures, Thiverval-Grignon, France.
    Loubet, B.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures, Thiverval-Grignon, France.
    Cellier, P.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures, Thiverval-Grignon, France.
    Mattsson, Marie
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Schjoerring, J.K.
    Plant and Soil Science Laboratory, University of Copenhagen, Faculty of Life Sciences, Copenhagen, Denmark.
    Nemitz, E.
    Centre for Ecology and Hydrology (Edinburgh Research Station), Bush Estate, Penicuik, Midlothian ,UK.
    Roche, R.
    Inst. National de la Recherche Agronomique, UMR Environnement et Grandes Cultures.
    Riedo, M.
    Inst. fur Agrarokologie, Bundesforschungsanstalt fur Landwirtschaft (FAL), Braunschweig, Germany.
    Sutton, M.A.
    Centre for Ecology and Hydrology (Edinburgh Research Station), Bush Estate, Penicuik, Midlothian ,UK.
    Ammonia sources and sinks in an intensively managed grassland canopy2009Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 6, nr 9, s. 1903-1915Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Grasslands represent canopies with a complex structure where sources and sinks of ammonia (NH3) may coexist at the plant level. Moreover, management practices such as mowing, hay production and grazing may change the composition of the sward and hence the source-sink relationship at the canopy level as well as the interaction with the atmosphere. There is therefore a need to understand the exchange of ammonia between grasslands and the atmosphere better, especially regarding the location and magnitude of sources and sinks. Fluxes of atmospheric NH3 within a grassland canopy were assessed in the field and under controlled conditions using a dynamic chamber technique (cuvette). These cuvette measurements were combined with extraction techniques to estimate the ammonium (NH+4 ) concentration and the pH of a given part of the plant or soil, leading to an estimated ammo- nia compensation point (Cp ). The combination of the cuvette and the extraction techniques was used to identify the poten- tial sources and sinks of NH3 within the different compart- ments of the grassland: the soil, the litter or senescent “litter leaves”, and the functioning “green leaves”. A set of six field experiments and six laboratory experiments were performed in which the different compartments were either added or removed from the cuvettes.The results show that the cuvette measurements agree with the extraction technique in ranking the strength of compartment sources. It suggests that in the studied grassland the green leaves were mostly a sink for NH3 with a compensation point around 0.1–0.4 μg m−3 and   an NH3 flux of 6 to 7 ng m−2 s−1. Cutting of the grass did not increase the NH3 fluxes of the green leaves. The litter was found to be the largest source of NH3 in the canopy, with a Cp of up to 1000μgm−3 NH3 andanNH3 fluxupto90ngm−2 s−1. The litter was found to be a much smaller NH3 source when dried (Cp =160 μg m−3 and FNH3 =35 ng m−2 s−1 NH3 ). Moreover emissions from the litter were found to vary with the relative humidity of the air. The soil was a strong source of NH3 in the period immediately after cutting (Cp =320 μg m−3 and FNH3 =60 ng m−2 s−1 ), which was nevertheless always smaller than the litter source. The soil NH3 emissions lasted, however, for less than one day, and were not observed with sieved soil. They could not be solely explained by xylem sap flow extruding NH+4 . These results indicate that future research on grassland-ammonia relationships should focus on the post-mowing period and the role of litter in interaction with meteorological conditions.

  • 11.
    Dejenfelt, Pontus
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Våtmarksfåglar i Stjärnarp, en inventering av nyanlagd våtmark utanför Halmstad, Halland2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Genom en kombinerad linjetaxering och revirkartering av nyanlagd våtmark i Stjärnarpsdalen utanför Halmstad under april-juni 2018 har jag undersökt artsammansättning, antal individer och par samt häckningskriteria hos fågelarter på plats. En jämförelse har gjorts med fem andra våtmarker i Halland i fråga om artsammansättning och häckninggskriteria för att undersöka om ålder eller storlek hos våtmarker har en effekt på dessa. Efter flertalet besök i Stjärnarp observerades totalt 55 arter varav 31 nyttjade våtmarken för antingen häckning, födosök eller rastade. Totalt 19 arter visade tecken på häckning inom våtmarkens gränser, varav endast fem arter slutligen fick ut avkomma. Hos samtliga undersökta våtmarker varierade antal arter mer under 2018, när de var av olika ålder, jämfört med när de alla var ungefär ett år gamla. Jag fann inga signifikanta korrelationer, beroenden eller skillnader mellan undersökta variabler, med undantag för signifikant korrelation och beroende mellan antal möjliga häckningar och area hos våtmarker. Enligt flera källor kan våtmarkers egenskaper och utformning ha stor betydelse för fåglars förekomst, t ex våtmarkens storlek, ålder, vattendjup, skötsel, placering, närvaro av fisk och mycket mer. I denna studie har Stjärnarp visats hysa arter som bl a häckar, och flera dessa arter indikerar på egenskaper som tidig succession, näringsrikt vatten, öppna strandängar och mer. Beroende på vad för fåglar och annan biologisk mångfald man vill gynna här i framtiden är planering och kontinuerligt uppföljningsarbete viktigt för att se om och hur fågelfaunan förändras samt vad det kan bero på.

  • 12.
    Eriksson, Cajza
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Protectors of the realm: - Are there species, native to Sweden, with higher resistibility to invasions by Lysichiton americanus L.?2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Invasiva främmande arter är idag ett av de största hoten mot biologisk mångfald eftersom de konkurrerar ut inhemska arter och snabbt kan ta över och dominera stora områden. Gul skunkkalla (Lysichiton americanus L.) finns på EU:s lista över invasiva arter av unions-betydelse sedan 2016 och är, lokalt, ett problem i Sverige. Under en förstudie med syfte att kartlägga förekomsten och habitatpreferens för L. americanus utmed Vinån i Falkenbergs kommun hittades cirka 30.000 individer, ett av de största bestånden i Sverige. Eftersom den ända lämpliga utrotningsmetoden är att gräva upp dem med rötterna kommer flera områden troligtvis vara i behov av restaurering, framför allt på platser med annars höga naturvärden. Många tidigare studier menar att restaurering bör göras med inhemska arter som har samma nisch som den invasiva. Andra studier indikerar också att det bör finnas inhemska arter som är mer resistenta mot invasioner. Syftet med huvudstudien var att se om det fanns växter längs Vinån, som är hemmahörande i Sverige och tycks ha en högre motståndskraft mot L. americanus. Resultaten av studien indikerar att arter ur Polypodiopsida och Equisetum samt Scirpus sylvaticus L., Filipendula ulmaria L. och Phalaris arundinacea L. konkurrerar med L. americanus och verkar ha en högre motståndskraft mot den. Arternas olika karaktärer och orsaker till varför de verkar ha en motståndskraft mot skunkkallan gås igenom i diskussionen liksom fördelarna med att använda inhemska arter med förhöjd motståndskraft.

  • 13.
    Eriksson, Peder G
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden .
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    An experimental study on effects of submersed macrophytes on nitrification and denitrification in ammonium-rich aquatic systems1999Ingår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 44, nr 8, s. 1993-1999Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have examined the role of microbial communities on the surface of submersed macrophytes and in the underlying sediment for nitrification and denitrification in light and dark in NH(4)(+)-enriched microcosm systems using isotope pairing and dilution techniques. Potamogeton pectinatus L. and intact sediment cores were collected in a shallow reservoir receiving treated municipal wastewater and containing dense submersed vegetation. Chambers containing P. pectinatus shoots, sediment, or both P. pectinatus shoots and sediment were exposed to 6 h of darkness, 6 h of light, and 6 h of darkness. (14)NH(4)(+) and (15)NO(3)(-) were added at ambient concentrations of 15 and 5 mg N liter(-1), respectively. NH(4)(+) was primarily nitrified in the epiphytic microbial communities, and NO; was denitrified in the underlying sediment. In chambers containing macrophytes, there was a net production of O(2) and NO(3)(-) in light and a net consumption in dark, and nitrification was higher in light than in dark. In chambers with only sediment, there was always a net consumption of NO(3)(-), and nitrification was similar in light and dark. The results show that submersed macrophytes can be important for the N metabolism in NH(4)(+)-rich freshwaters (e.g., wastewater treatment systems) by stimulating nitrification through providing surfaces for attached nitrifying bacteria and possibly also through diurnal changes in the water chemistry.

  • 14.
    Eriksson, Peder G.
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Functional differences in epiphytic microbial communities in nutrient-rich freshwater ecosystems: An assay of denitrifying capacity1996Ingår i: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 36, nr 3, s. 555-562Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. The denitrifying capacity of epiphyton was used to evaluate differences in the function of epiphytic microbial communities on submersed macrophytes in nutrient-rich freshwater ecosystems. The denitrifying capacity of epiphyton on Patamogeton perfoliatus shoots of different age and with different epiphytic abundances from a eutrophic lake was investigated in laboratory microcosms in the Light and dark. Additionally, differences between epiphyton on shoots of Potamogeton pectinatus grown under different in Situ nutrient and hydraulic conditions were investigated by examining their denitrifying capacity. 2. Denitrification was registered in well-developed epiphytic layers on both mature and senescent shoots in the dark, with activities 3- to 10-fold higher in the epiphytic communities of senescent shoots. No activity was detected on young shoots with sparse epiphyton or on shoots from which loosely attached epiphyton had been removed. Denitrification never occurred during illumination. 3. Even though the epiphytic abundance was similar in magnitude, the denitrifying capacity of epiphyton adapted to high nutrient loadings was about a hundred times higher than that of epiphyton adapted to lower nutrient levels. Additionally, epiphytic abundance and denitrifying capacity were higher at sites less exposed to wave turbulence or water currents, than at sites with more water turbulence. 4. The results illustrate how the hydraulic and nutrient conditions of the surrounding water affect both the quantity and function of epiphytic microbial communities in nutrient-rich freshwater ecosystems.

  • 15.
    Eriksson, Peder G.
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Nitrogen removal in a wastewater reservoir: The importance of denitrification by epiphytic biofilms on submersed vegetation1997Ingår i: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 26, nr 3, s. 905-910Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to examine the importance of epiphytic denitrifying bacteria on submersed vegetation in removing N from a shallow nutrient-enriched freshwater ecosystem. The investigation was conducted during the summer of 1994 in a surface now reservoir receiving municipal tertiary-treated wastewater. The submersed vegetation in the reservoir was dominated by Potamogeton pectinatus L. and filamentous green algae (FGA). The N loading was 2300 mg N h(-1) m(-2) and the N removal, calculated as the mean difference between influent and effluent N, was 190 mg N h(-1) m(-2) (8%). The majority of influent N consisted of NH4+, but the main part of the N removal was due to the removal of NO3- whereas no net retention of NH4+ was found. Mean total soluble solids and BOD7 retention was 69 and 38%, respectively, Denitrification measurements were conducted in darkness at in situ temperature in microcosms with P. pectinatus, FGA, or infect sediment cores. Epiphytic denitrification ranged between 0.21 to 7.0 mg N h(-1) m(-2) reservoir surface area depending on the abundance of the submersed vegetation (5-140 g DW m(-2)). Sediment denitrification was 4.7 mg N h(-1) m-L reservoir surface area. The mean assimilative N uptake of the submersed vegetation and epiphyton was 3.4 and 1.6 mg N h(-1) m(-2) reservoir surface area, respectively. Measured N removal rates through plant uptake and denitrification could only account for a minor part of the N removal observed by mass balance. However, microcosm denitrification measurements underestimate actual denitrification. Thus, the major part of the N removal was most likely due to denitrification. In conclusion, this study indicates that denitrification in epiphytic microbial communities on submersed vegetation can be of significant importance for the N removal in nutrient-enriched freshwater ecosystems.

  • 16. Eriksson, P.G.
    et al.
    Svensson, J.M.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Våtmarkscentrum.
    Carrer, M.
    Dipto. Proc. Chimici dell'Ingegneria, Université di Padova, Padua, Italy.
    Temporal changes and spatial variation of soil oxygen consumption, nitrification and denitrification rates in a tidal salt marsh of the Lagoon of Venice, Italy2003Ingår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 58, nr 4, s. 861-871Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of the present study was to investigate seasonal and spatial patterns of soil oxygen consumption, nitrification, denitrification and fluxes of dissolved inorganic nitrogen (DIN) in a tidal salt marsh of the Lagoon of Venice, Italy. In the salt marsh, intact soil cores including overlying water were collected monthly at high tide from April to October in salt marsh creeks and in areas covered by the dominant vegetation, Limonium serotinum. In May, cores were also collected in areas with vegetation dominated by Juncus maritimus and Halimione portulacoides. In laboratory incubations at in situ temperature in the dark, flux rates of oxygen and DIN were monitored in the overlying water of the intact cores. 15N-nitrate was added to the overlying water and nitrification and denitrification were measured using isotope-dilution and -pairing techniques. The results show that highest soil oxygen consumption coincided with the highest water temperature in June and July. The highest denitrification rates were recorded in spring and autumn coinciding with the highest nitrate concentrations. Soil oxygen consumption and nitrification rates differed between sampling sites, but denitrification rates were similar among the different vegetation types. The highest rates were recorded in areas covered with L. serotinum. Burrowing soil macrofauna enhanced oxygen consumption, nitrification and denitrification in April and May. The data presented in this study indicate high temporal as well as spatial variations in the flux of oxygen and DIN, and nitrogen transformations in the tidal salt marshes of the Venice lagoon during the growth season. The results identify the salt marshes of the Venice lagoon as being metabolically very active ecosystems with a high capacity to process nitrogen.

  • 17.
    Graneli, Wilhelm
    et al.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Weisner, Stefan E.B.
    Limnology, Department of Ecology, Lund University, Lund, Sweden.
    Sytsma, Mark D.
    UC Davis, Department of Botany, Davis, United States.
    Rhizome dynamics and resource storage in Phragmites australis1992Ingår i: Wetlands Ecology and Management, ISSN 0923-4861, E-ISSN 1572-9834, Vol. 1, nr 4, s. 239-247Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Seasonal changes in rhizome concentrations of total nonstructural carbohydrates (TNC), water soluble carbohydrates (WSC), and mineral nutrients (N, P and K) were monitored in two Phragmites australis stands in southern Sweden. Rhizome biomass, rhizome length per unit ground area, and specific weight (weight/ length ratio) of the rhizomes were monitored in one of the stands. Rhizome biomass decreased during spring, increased during summer and decreased during winter. However, changes in spring and summer were small (< 500 g DW m-2) compared to the mean rhizome biomass (approximately 3000 g DW m-2). Winter losses were larger, approximately 1000 g DW m-2, and to a substantial extent involved structural biomass, indicating rhizome mortality. Seasonal changes in rhizome length per unit ground area revealed a rhizome mortality of about 30% during the winter period, and also indicated that an intensive period of formation of new rhizomes occurred in June. Rhizome concentrations of TNC and WSC decreased during the spring, when carbohydrates were translocated to support shoot growth. However, rhizome standing stock of TNC remained large (> 1000 g m-2). Concentrations and standing stocks of mineral nutrients decreased during spring/ early summer and increased during summer/ fall. Only N, however, showed a pattern consistent with a spring depletion caused by translocation to shoots. This pattern indicates sufficient root uptake of P and K to support spring growth, and supports other evidence that N is generally the limiting mineral nutrient for Phragmites. The biomass data, as well as increased rhizome specific weight and TNC concentrations, clearly suggests that "reloading" of rhizomes with energy reserves starts in June, not towards the end of the growing season as has been suggested previously. This resource allocation strategy of Phragmites has consequences for vegetation management. Our data indicate that carbohydrate reserves are much larger than needed to support spring growth. We propose that large stores are needed to ensure establishment of spring shoots when deep water or stochastic environmental events, such as high rhizome mortality in winter or loss of spring shoots due to late season frost, increase the demand for reserves. © 1992 SPB Academic Publishing.

  • 18.
    Gustavsson, Oscar
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Increased Browning Alters Zooplankton Composition: A Mesocosm Study in Lake Bolmen2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Under de senaste årtiondena har många limniska system på det norra halvklotet fått en ökadvattenfärg, ett fenomen även känt som’’brunifiering’’. Effekter av detta fenomen harobserverats att ha en påverkan på planktonsamhällen. Brunifiering är känt för att ändraljusklimatet i akvatiska system och således, primärproduktionen. Man tror att detta fenomenkommer öka parallellt med klimatförändringar i framtiden och i och med planktonsamhällensnyckelroll i akvatiska system har det blivit allt mer brådskande att studera dess påverkan. Ettmesokosmexperiment utfördes under sommaren 2018 i sjön Bolmen för att studera potentiellaframtida förhållanden av brunifiering (50 år och 100 år från dagens förhållanden). Resultatenfrån studien visade att brunifiering påverkade Daphnia spp. positivt med en ökad förekomst iden kraftigt bruna behandlingen. En diskriminantanalys visade även att brunifiering kan kommaatt förändra släktsammansättningen av djurplankton inom 100 år.

  • 19.
    Hansson, Jessica
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Ekologi och miljövetenskap.
    Does the wolf (Canis lupus) affect presence of the red fox (Vulpes vulpes) in Sweden?2014Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Vargen (Canis lupus) har ökat stadigt i Sverige under de senaste decennierna. Vargens återkomst och dess påverkan på det svenska djurlivet studeras idag i stor utsträckning, och frågor har uppstått om vargen som toppredator kan komma att orsaka trofiska kaskader i ekosystemet, vilket har observerats i nationalparker i USA. Rödräven (Vulpes vulpes) har i Sverige visat sig dra stor nytta utav vargens återkomst genom den ökade mängden kadaver som vargen lämnar, vilket är en särskilt viktig födokälla under våren.

    Syftet med denna studie var att undersöka om närvaro av varg påverkar förekomst av rödräv. Rävspår räknades i 182 vilttrianglar i Örebro och Värmlands län under åren 2001-2003. Vilttrianglarna klassificerades med avseende på mängd jordbruksmark, avstånd till vargrevir och ålder på vargrevir. Effekt av varg på rävförekomst analyserades genom att jämföra rävspår med distans till vargrevir och hur länge det funnits varg i området samt rävspår i relation till mängd jordbruksmark. Studien kunde inte påvisa någon effekt av vargförekomst på räv.  Resultaten indikerar på att habitatet var nyckelfaktorn för rävförekomst istället för närvaro av varg. I och med att vargstammen ökar stadigt i Sverige är det dock av intresse med fortsatta studier i ämnet då vargen kan komma att spela en större roll i ekosystemet i framtiden.

  • 20.
    Hedström, Ingemar
    et al.
    Boston University, College of Arts and Sciences, Boston, MA, United States.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    An extended description of the larva of Megaloprepus caerulatus from Costa Rica (Odonata: Pseudostigmatidae)2003Ingår i: International Journal of Odonatology, ISSN 1388-7890, Vol. 6, nr 1, s. 23-31Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The larva of Megaloprepus caerulatus is described and illustrated from specimens collected near the northern border of Barbilla National Park on the Costa Rican Caribbean slope. Habits and characters of larvae of three different size classes obtained from artificial tree holes permit the identification of small (body length 4 mm, excluding the caudal lamellae) larvae up to the final stadium. New diagnostic characters include the shape of the prementum and head. © 2003 Taylor & Francis Group, LLC.

  • 21.
    Ivarsson, Sofia
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Invertebrate colonisation and diversity in constructed wetlands in Halland: A comparison between 2004 and 20062017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 22.
    Jaggwe, Assad
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Effects of Environmental Variables on Four Aquatic Insect Taxa among Smaller Water Bodies of Different Ages on Farmland; A Pilot Study2015Självständigt arbete på avancerad nivå (masterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    High anthropogenic modification like infrastructural development, drainage, eutrophication, dumping garbage, is a threat to biodiversity of smaller water bodies in agricultural landscapes. However, smaller water bodies have historically been constructed for drainage, waste treatment and other purposes. Further, new small water bodies are now being constructed in agricultural areas in Sweden, mainly to remove nutrients and to improve landscape biodiversity. This creates two different age classes (old and new) of smaller water body habitats. I sampled aquatic insects in 27 smaller water bodies of varying types and ages in Halmstad region and related insect biodiversity, species richness, composition structure to environmental variables. I partitioned the region into two locations (Northern and Southern) for easy data comparison and due to difference in topography. The data was analysed using a Canonical Correspondence (CCA) and regression analysis. The CCA results show a difference in the species composition between old and new sites. The most important variables in explaining species assemblage structure was age of the aquatic water bodies. The species richness decreased with increase in nutrient concentration (total phosphorus) according to regression analysis. Species composition and diversity were related to Vegetation and tree cover in and around the water body. The results of my study shows that the older the water bodies the better for specific species like Aeshna cyanea and the new water bodies tolerate more specimens. My results suggest that, as there is need to facilitate plant growing, protecting vegetation and trees to better mimic natural conditions of water bodies, creating new water bodies while protecting aged water bodies is important for conservation of biodiversity.

  • 23.
    Jarnemo, Anders
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS). Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, SE-730 91 Riddarhyttan, Sweden.
    Minderman, Jeroen
    Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
    Bunnefeld, Nils
    Biological and Environmental Sciences, University of Stirling, Stirling FK9 4LA, United Kingdom.
    Zidar, Josefina
    Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden.
    Månsson, Johan
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Sciences, SE-730 91 Riddarhyttan, Sweden.
    Managing landscapes for multiple objectives: Alternative forage can reduce the conflict between deer and forestry2014Ingår i: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 5, nr 8Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Deer (Cervidae) cause considerable damage to forest plantations, crops, and protected habitats. The most common response to this damage is to implement strategies to lower population densities. However, lowering deer density may not always be desirable from hunting, recreational, or conservation perspectives. Therefore, knowledge is needed about additional factors beyond deer density that affect damage levels, and management actions that consider competing management goals. We studied the relationships between levels of bark-stripping by red deer (Cervus elaphus) on Norway spruce (Picea abies) and (1) relative deer density indices (pellet group count and deer harvest data), (2) availability of alternative natural forage (cover of forage species) and (3) proportion forest in the landscape, both at a forest stand scale and at a landscape scale. Extensive variation in damage level was evident between the six study areas. On a stand scale, the proportion of spruce damaged was positively related to pellet group density, indicating the importance of local deer usage of stands. In addition, available alternative forage in the field layer within spruce stands and proportion forest surrounding stands was negatively related to damage level. On the landscape scale, damage level was negatively related to availability of forage in the field and shrub layers and proportion forest, but was not related to any of the relative deer density indices. Increasing alternative forage may thus decrease damage and thereby reduce conflicts. Additionally, the proportion of forest in the landscape affects damage levels and should thus be considered in landscape planning and when forecasting damage risk. The relationship between local deer usage of stands and damage level suggests that future studies should try to separate the effects of local deer usage and deer density. © 2014 Jarnemo et al.

  • 24.
    Johannesson, Malin
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Prey choice of the snow leopard (Panthera uncia) in the Gobi desert in southern Mongolia.2014Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    För att kunna planera en bevarandestrategi för stora, svårfångade rovdjur som bor i avlägsna områden, finns det ett behov av korrekt information om deras föda. Problem uppkommer då starkt hotade arter som snöleoparden är svåra att samla information ifrån, då deras kamouflage, hemlighetsfullhet och isolerade liv i svårtillgängliga ekosystem försvårar arbetet. GPS-halsband (Globalt positions system) kan ge värdefull information om djurs ekologi och beteende. Studien ägde rum i Gobiöknen i södra Mongoliet, och syftade till att undersöka snöleoparders bytes val. Totalt fångades 19 snöleoparder mellan 2008 och 2013 och som försågs med GPS-halsband. Dessa halsband registrerade en position var femte till sjunde timme. Bytes platser hittades genom att besöka kluster med GPS-positioner. Stenbock var det bytet som dominerade (66 %), följt av get och får (20 %) och därefter argali (8 %). Stenbockarna och argali köns och ålders klassificerades. Ålder och köns förhållanden av de slagna stenbockarna skilde sig från ålder och köns förhållanden av stenbockspopulationen. Vuxna stenbockars hanar tycktes vara överrepresenterade bland de slagna (hanar <5 år 10 % och hanar > 5 år 35 %), medan honorna verkade vara underrepresenterade. Även hos argali var kategorin med de flesta slagna hanar (56 %). Resultaten visar att snöleoparder inte bara slår byten större än sig själva, de verkar även välja de största ålder- och köns- kategorierna bland stenbock och argali, även om de olika kategorierna som blev slagna varierade mellan säsongerna. Tänkbara förklaringar till resultaten diskuteras.  Resultatet av denna studie kommer att bidra till förståelse av snöleoparders födoekologi, och hur man ska ta itu med bevarande- och förvaltningsfrågor i hur man kan bevara denna katt och dess viktigaste bytesdjur.

  • 25.
    Johansson, Alfred
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Hållbar vattenkraft i Nissan: En förstudie och konsekvensutredning över förutsättningarna för ökade vandringsmöjligheter med nya fiskvägar.2015Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The hydropower from Nissan River is of national interest and produces annually 230 GWh from the twelve power stations in the main flow. For modified waters a consideration between the power production and the biological values has to be made. This reports serves as a pre-study for Nissans Vattenråd. It tries to evaluate some of the biological values in the Nissan basin and map the power production in the area. And the size and value of lost power production from new fishways for the twelve stations in the main flow.

    The investment of new fishways is calculated using simplified templates with values from the business. The cost and loss of power due to new fishways are calculated for three cases: fish friendly grates for the power station inlet and bypass for migration. Fish friendly grate and vertical-slot fish passage for migration. The last case is called “scenario” and is a combination with the most suited solution for each station. This includes a restoration of the creek, with maintained power production, for the two stations closest to the ocean.

    The cost for fish friendly grade and bypass for al stations is about 207 mskr and for vertical-slot fish passage 125 mskr. They both result in a loss of power production of 12 GWh/year, corresponding to a value of 3,2 mskr (NordSpot sale price only) annually. Case “scenario” costs 177 mskr and loses additionally 4,2 GWh/year.

    In the overview, large parts of the Nissan runoff has difficulties reaching “god ecological status” which is the goal set for 2021. This goal can be extended to 2027. The main problem is chemical effect of acidification and mercury in the ground, as well as connectivity issue caused by dams and culverts. Salmon and sea trout could earlier migrate to Nissafors and is limited to the lower parts of Nissan to Oskarström. Many of the tributary waters have high biological values. The existing fishways have questioned functionality and delays fish migration today. Before decisions are made about increasing fishways the advice is to do further studies about the breeding grounds. It’s also possible to identify positive cash flows from an increase in fish migration.

  • 26.
    Koch, Kamilla
    et al.
    Department of Ecology, Johannes Gutenberg-University of Mainz, Mainz, Germany.
    Wagner, Christine
    Department of Ecology, Johannes Gutenberg-University of Mainz, Mainz, Germany.
    Sahlén, Göran
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Farmland versus forest: comparing changes in Odonata species composition in western and eastern Sweden2014Ingår i: Insect Conservation and Diversity, ISSN 1752-458X, E-ISSN 1752-4598, Vol. 7, nr 1, s. 22-31Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Despite the loss of natural ecosystems in the developed world during the past millennia, anthropogenic landscapes still sustain much biodiversity. Our question was, whether ten year changes in regional Odonata faunas are comparable between farmland and forested areas, or if the species pool of farmland areas respond in other ways than that of forest.

    2. We used data of dragonfly larvae collected from 16 lakes in a farmland area in south-western Sweden in the years 2002 and 2011/12, and compared these to data from 34 lakes in a forest area in south-eastern Sweden in the years 1996 and 2006.

    3. The species-richness in the agricultural region increased by 17% but decreased by 13% in the forested region. The changes in occurrence and regional distribution were similar in both areas, affecting 71% and 69% of the species pool. Average extinction rates were comparable between the agricultural and the forested region (38% and 43%) while colonisation rates differed greatly (64% and 114%).

    4. The species composition differed between the regions; the forest lakes harboured a 29% larger species pool. It is possible that in the forested region, the regional species pool in areas surrounding the study sites could stabilise the extinction and have a positive effect on changes in species composition. We assume that the different habitat structures of the waters in the agricultural and the forest regions and changes in temperature are the main driving forces behind the shifts. The mean seasonal air temperature has increased by circa 0.5°C in both regions, when comparing ten-year periods before each sampling year.

  • 27.
    Korkeamäki, Esa
    et al.
    Water and Environment Association of the River Kymi, Kouvola, Finland.
    Elo, Merja
    University of Jyväskylä, Jyväskylä, Finland.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Salmela, Jukka
    Regional Museum of Lapland, Rovaniemi, Finland.
    Suhonen, Jukka
    University of Turku, Turku, Finland.
    Regional variations in occupancy frequency distributions patterns between odonate assemblages in Fennoscandia2018Ingår i: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 9, nr 4, artikel-id e02192Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Odonate (damselfly and dragonfly) species richness and species occupancy frequency distributions (SOFD) were analysed in relation to geographical location in standing waters (lakes and ponds) in Fennoscandia, from southern Sweden to central Finland. In total, 46 dragonfly and damselfly species were recorded from 292 waterbodies. Species richness decreased to the north and increased with waterbody area in central Finland, but not in southern Finland or in Sweden. Species occupancy ranged from 1 up to 209 lakes and ponds. Over 50% of the species occurred in less than 10% of the waterbodies, although this proportion decreased to the north. In the southern lakes and ponds, none of the species occurred in all lakes, whereas in the north many species were present in all of the studied waterbodies. The dispersal ability of the species did not explain the observed species occupancy frequencies, but generalist species with a large geographical range occurred in a higher percentage of the waterbodies. At Fennoscandian scale, we found that the unimodal satellite pattern was predominant. However, at smaller scale, we found geographical variations in odonate species SOFD patterns. The most southern communities followed the unimodal satellite-dominant pattern, whereas in other regions communities fitted best with the bimodal core - satellite patterns. It seems that the richer species pool in the southern locations, and the larger distribution range of the northern species, skewed the unimodal pattern into a bimodal satellite dominant pattern. © 2018 The Authors.

  • 28.
    Larsson, Matilda
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Ekologi och miljövetenskap.
    Inventering av Strandpadda (Bufo calamita) 2012 på Balgö och inom Varbergs kust2012Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 29.
    Lindén, Ann-Sofie
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Uggla Viktorsson, Marcus
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Typ och grad av samband mellan skador på stammar och rötter av gran till följd av vildsvinsbök (troliga angreppspunkter för rotröta) och vildsvinspopulationens täthet2012Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Den svenska vildsvinspopulationen har under senaste decenniet expanderat kraftigt både i storlek och i utbredning i landet. Att vildsvinen (Sus scrofa) orsakar problem inom jordbruket är väl känt och flertalet studier har gjorts inom området. Det finns dock få uppgifter kring vildsvinens betydelse inom skogsbruket. Det är tänkbart att vildsvinens bök skulle kunna både orsaka röta (via skador på rötter) och även påverka spridningen av röta mellan granbestånd. Om så är fallet leder det till försämrad vedkvalitet och därmed negativa ekonomiska konsekvenser för brukaren.Detta är en pilotstudie som ingår i ett större forskningsprojekt kring vildsvin och dess förvaltning. Syftet med studien var att via en fältstudie och årlig statistik samla in data som indikerar typ och grad av samband mellan skador på stammar och rötter till följd av vildsvinsbök (troliga angreppspunkter för rotröta) på gran (Picea abies). Skador relaterades vidare till bökens djup, marktyp (ursprunglig skogsmark respektive gammal åkermark), beståndsålder och ett index för vildsvinspopulationens täthet.Fältstudien genomfördes som inventering av vildsvinsbök längs linjetransekter med 50 meters mellanrum i granbestånd (30-70 år gamla, markägare Sveaskog). Inventeringarna gjordes i södra Sverige i trakter kring Ulricehamn, Kalmar, Ljungby, Burseryd och Växjö.Totalt noterades 683 bök i sammanlagt 40 olika bestånd. Bök med skador samt bök med blottlagda rötter är de som kan leda till framtida rötangrepp på granarna, och utgjorde tillsammans 57 % av alla bök i bestånden. I bökdjupen 6-10 cm är risken för rötskador över 50 % och i bökdjupen 11-20 cm är risken över 70 %. Av det totala antalet bök var 46 % från gammal åkermark och 54 % från ursprunglig skogsmark. Det finns även ett positivt samband mellan antal år med vildsvin i området och mängden bök, liksom ökad mängd skadade rötter. Resultatet visade att det finns risk för att vildsvinsbök, på sikt, skulle kunna orsaka rötangrepp på gran.

  • 30.
    Lundquist, Kristin
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Vildsvinsbök i skogsmark – en studie i tre områden i Mellansverige2016Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I april-juli år 2010 undersöktes tre studieområden i mellersta Sverige avseende hur fördelningen av vildsvinsbök såg ut i dessa områden. Resultaten visade att vildsvinsbök främst återfanns i miljöer dominerade av tall-och granskog där åldern på träden låg runt 45-90 år, samt med fältskikt bestående av bärris, mossa eller gräs. På två utav de tre lokalerna påverkades inte arealen på bök av faktorer såsom trädartsammansättning, trädålder eller fältskikt men det fanns däremot korrelationer mellan dessa faktorer på en utav lokalerna. Vidare påverkades arealen på bök inte av populationstäthet eller hur lång tid vildsvin förekommit i området.

  • 31.
    Lundén, Eric
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Mossfloran vid vattenkvarnar i sydöstra Sverige2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Mossor spelar en viktig roll i ekosystem i rinnande vatten och är vanligt förekommande på strukturer i och vid vattenkvarnar. Dessa habitat skiljer sig från vattendraget i övrigt bland annat genom annorlunda mikroklimat och störningsregim, men också genom en hög mångfald av för mossor lämpliga substrat. I denna studie undersöktes mossfloran vid fem vattenkvarnar och fem referensområden. Artantal jämfördes mellan kvarn- och referensområden och skillnader i artsammansättning analyserades med en diskriminantanalys. I 90% av fallen var artsammansättning specifik för respektive habitat och medeltalet för antalet arter var 57% högre vid vattenkvarnar jämfört med referensområden. Stenar och block i olika storlekar, betong och murbruk med högre pH-värden än den underliggande berggrunden och starkare strömmar är några av de faktorer som bidrog till den ökade artmångfalden vid vattenkvarnarna. Restaureringsprojekt i rinnande vatten, till exempel dammutrivningar, utgör ett potentiellt hot mot mossfloran vid vattenkvarnar eftersom de strukturer mossorna växer på riskerar att antingen förstöras eller tas bort. Förändringar i mikroklimat och störningsregim är två andra potentiella hot mot arter i dessa miljöer.

  • 32.
    Noreman, Rickard
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Pollinerande insekters (Apidae, Rhopalocera och Syrphidae) förekomst intill vägar i södra Sverige.2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    More conservation programs directed towards insects are needed in order to prevent the continue decline in which many insect species in the world are heading to. New ways to use the remaining microhabitats are needed to mitigate the fragmentation and degradation that urbanization and modern agriculture have contributed to in the southern Swedish landscapes. This study focusses on how microhabitats like road-verges can help the conservation projects of pollinating insects. To increase the knowledge about three groups of pollinators (Apidae, Rhopalocera and Syrphidae) and their distribution between two different microhabitats, a malaise trap was set up in road verges and in sample locations further away from the road-verges. The result from this study shows that road-verges are a microhabitat that could work as mitigation to the decline of some pollinating species, if right actions are taken. This study shows that Syrphidae was most acceptant to the hostile environment close to the roads. If these actions are going to help the most treated species is still unknown.

  • 33.
    Persson, Linnéa
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Skyddsvärda kärlväxter i Haväng och Vitemölla strandbackar: – utbredning, hot och skötsel2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Ängs-och hagmarker är några av de mest hotade och viktiga habitattyperna i Skandinavien. Gräsmarken som studerades i detta projekt ligger i norra delarna av naturreservatet Haväng och Vitemölla strandbackar i Skåne och består av gräsbevuxna sanddyner och en hage med inslag av kalkgräsmark och marktypen sandstäpp som är väldigt sällsynt i Sverige. I reservatet finns flera skyddsvärda kärlväxter och under sommaren 2017 kartlades deras utbredning för att bättre kunna skydda dem vid skötsel- och restaureringsåtgärder. Resultatet visade att större delen av området innehåller skyddsvärda arter och att de mest skyddsvärda områdena var de delar av området där det fanns inslag av sandstäpp. Detta beror med stor sannolikhet på att de flesta skyddsvärda arterna i området var knutna till de torra, sandiga, kalkhaltiga och näringsfattiga förhållanden som rådde där. De flesta skyddsvärda arter fanns i stora antal i det undersökta området men har en begränsad utbredning i Sverige. Populationen av Eryngium maritimum var dock så litet att det hotas av utrotning. I övrigt hotas växterna i området på längre sikt av ökad tillsättning av näringsämnen och långvarig urlakning av kalk. Detta kan leda till lägre pH och mer näringsrik mark och gör att den nuvarande artsammansättningen kan försvinna och ersättas. För att området ska fortsätta ha en gynnsam status kommer det krävas fortsatt bete, skapande av sandblottor för att röra upp kalkrik sand samt åtgärder så som avlägsnande av förna och ytskikt för att hålla nere näringshalten. Det stora antalet rödlistade och skyddsvärda arter i området gör dock att det krävs varsamhet och noggrann planering vid en åtgärd, framför allt i sandstäppsområdena.

  • 34.
    Peters, Wibke
    et al.
    Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT, United States & Bavarian State Institute of Forestry (LWF), Freising, Germany.
    Hebblewhite, Mark
    Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT, United States.
    Mysterud, Atle
    Centre for Ecological and Evolutionary Synthesis, Department Biosciences, University of Oslo, Oslo, Norway.
    Eacker, Daniel
    Wildlife Biology Program, Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, MT, United States.
    Hewison, A. J. Mark
    CEFS, University de Toulouse, INRA, Castanet Tolosan, France.
    Linnell, John D. C.
    Norwegian Institute for Nature Research (NINA), Trondheim, Norway.
    Focardi, Stefano
    stituto dei Sistemi Complessi, CNR, Sesto Fiorentino, Italy.
    Urbano, Ferdinando
    Eurodeer Project, freelance consultan.
    De Groeve, Johannes
    Department of Geography, Ghent University, Gent, Belgium.
    Gehr, Benedikt
    Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.
    Heurich, Marco
    Department of Conservation and Research, Bavarian Forest National Park, Grafenau, Germany.
    Jarnemo, Anders
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Kjellander, Petter
    Grimsö Wildlife Research Station, Department of Ecology, Swedish University of Agricultural Science (SLU), Riddarhyttan, Sweden.
    Kröschel, Max
    Chair of Wildlife Ecology and Management, University of Freiburg, Freiburg, Germany & Forest Research Institute of Baden-Wuerttemberg, Freiburg im Breisgau, Germany.
    Morellet, Nicolas
    CEFS, University de Toulouse, INRA, Castanet Tolosan, France.
    Pedrotti, Luca
    Parco Nationale dello Stelvio, Glorenza (BZ), Italy.
    Reinecke, Horst
    Department of Wildlife Sciences & Institute for Wildlife biology of Göttingen and Dresden, University of Göttingen, Göttingen, Germany.
    Sandfort, Robin
    Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna, Austria.
    Sönnichsen, Leif
    Mammal Research Institute, Polish Academy of Sciences, Białowieża, Poland & Leibniz Institute for Zoo and Wildlife Research (IZW), Berlin, Germany.
    Sunde, Peter
    Deptartment of Bioscience – Wildlife Ecology, Aarhus University, Aarhus, Denmark.
    Cagnacci, Francesca
    Biodiversity and Molecular Ecology Department, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige (TN), Italy & Organismic and Evolutionary Department, Harvard University, Cambridge, MA, United States.
    Large herbivore migration plasticity along environmental gradients in Europe: life-history traits modulate forage effects2018Ingår i: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 128, nr 3, s. 416-429Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The most common framework under which ungulate migration is studied predicts that it is driven by spatio–temporal variation in plant phenology, yet other hypotheses may explain differences within and between species. To disentangle more complex patterns than those based on single species/ single populations, we quantified migration variability using two sympatric ungulate species differing in their foraging strategy, mating system and physiological constraints due to body size. We related observed variation to a set of hypotheses. We used GPS-collar data from 537 individuals in 10 roe Capreolus capreolus and 12 red deer Cervus elaphus populations spanning environmental gradients across Europe to assess variation in migration propensity, distance and timing. Using time-to-event models, we explored how the probability of migration varied in relation to sex, landscape (e.g. topography, forest cover) and temporally-varying environmental factors (e.g. plant green-up, snow cover). Migration propensity varied across study areas. Red deer were, on average, three times more migratory than roe deer (56% versus 18%). This relationship was mainly driven by red deer males which were twice as migratory as females (82% versus 38%). The probability of roe deer migration was similar between sexes. Roe deer (both sexes) migrated earliest in spring. While territorial male roe deer migrated last in autumn, male and female red deer migrated around the same time in autumn, likely due to their polygynous mating system. Plant productivity determined the onset of spring migration in both species, but if plant productivity on winter ranges was sufficiently high, roe deer were less likely to leave. In autumn, migration coincided with reduced plant productivity for both species. This relationship was stronger for red deer. Our results confirm that ungulate migration is influenced by plant phenology, but in a novel way, that these effects appear to be modulated by species-specific traits, especially mating strategies. © 2018 The Authors. Oikos © 2018 Nordic Society Oikos

  • 35.
    Petersson, Linn
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Hur markegenskaper i produktionsskog påverkas av bök från vildsvin (Sus scrofa) i sydvästra Sverige2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A balance between large-scale and small-scale disturbance is important for maintaining species diversity on landscape level. Wild boar rooting contributes to small-scale disturbance when leaving patches bare of soil. Knowledge is scarce regarding their impact on soil properties in managed spruce forests in south-west Sweden. Therefore, the objective of this study was to determine the effects of wild boar rooting on soil physical and chemical properties, by taking soil samples from the centre, the edge and outside of disturbed patches. Rooting activities significantly increased soil moisture, organic matter, total N and pH but did not affect total P in this study. Areas with high number of disturbed patches had higher soil moisture and organic matter compared to areas with intermediate and few disturbed patches. These new soil characteristics can favour species diversity and ultimately increase productivity in managed forests. The results of this study indicate that wild boar activity contributes to more positive than negative effects in managed spruce forests and focus should therefore lie on preventing wild boar rooting in other areas more sensitive to this disturbance. It is also important to disseminate information and knowledge about the wild boar's positive and negative impact on managed forests in order to better prevent the negative effects and strengthen the positive ones.

  • 36.
    Pires, Mateus Marques
    et al.
    Ecology and Evolution Laboratory, Vale do Taquari University (UNIVATES), Lajeado, Rio Grande Do Sul, Brazil.
    Périco, Eduardo
    Ecology and Evolution Laboratory, Vale do Taquari University (UNIVATES), Lajeado, Rio Grande Do Sul, Brazil.
    Renner, Samuel
    Ecology and Evolution Laboratory, Vale do Taquari University (UNIVATES), Lajeado, Rio Grande Do Sul, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Predicting the effects of future climate change on the distribution of an endemic damselfly (Odonata, Coenagrionidae) in subtropical South American grasslands2018Ingår i: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 22, nr 2, s. 303-319Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Climate change is predicted to affect the distribution of freshwater taxa, and stronger impacts are expected on endemic species. However, the effects of future climates on freshwater insects from the Neotropical region have been generally overlooked. In this study, the distribution of a damselfly (Cyanallagma bonariense, Odonata, Coenagrionidae) endemic to the subtropical South American grasslands (Pampa) was modelled in relation to future scenarios of high greenhouse gas emissions (RCP 8.5) for 2050 and 2070. For this purpose, ecological niche models were developed based on assumptions of limited dispersal and niche conservatism, and the projected distribution of C. bonariense was contrasted with the location of current protected areas (PAs) in the Pampa. A broad potential distribution of C. bonariense was indicated throughout the Pampa, and projections predicted a predominance of range contractions rather than range shifts in climatically suitable areas for C. bonariense in 2050 and 2070. Projections of suitable areas overlapped in central Argentina and southernmost Uruguay in these periods. Our results indicated a potential resilience of C. bonariense to future climate change, which is likely related to the low restrictions in habitat use of C. bonariense. In every projection, however, most PAs were expected to lose effectiveness, as by 2070 most PAs fall outside the range of the predicted distribution of C. bonariense. Thus, the creation or enlargement of PAs in these areas is recommended and these results represent an important information for the conservation of endemic freshwater insects under global warming scenarios in an overlooked Neotropical landscape. © Springer International Publishing AG, part of Springer Nature 2018

  • 37.
    Pålsson, Joakim
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Ekologi och miljövetenskap.
    Geografisk spridning och morfologisk variation hos Brachygaster minutus (Hymenoptera: Evaniidae) i Sverige2012Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 38.
    Renner, Samuel
    et al.
    Ecologia e Sensoriamento Remoto, Centro Universitário Univates, Lajeado-RS, Brazil.
    Perico, Eduardo
    Ecologia e Sensoriamento Remoto, Centro Universitário Univates, Lajeado-RS, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Dragonflies (Odonata) in Subtropical Atlantic Forest fragments in Rio Grande do Sul, Brazil: seasonal diversity and composition2013Ingår i: Scientia Plena, ISSN 1808-2793, Vol. 9, nr 1, artikel-id 012401Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    One of the most endangered ecosystems in America is the Atlantic Forest, which demands emergency actions to protect its remnants as well its biodiversity. In this situation the species inventory can develop a management role for the future, determining specific areas that should be preserved as well the species composition and richness can be used as an indicator of a healthy ecosystem. The use of dragonfly species composition has proven its potential indication of quality habitats. The Odonata species actually still poorly known in the Neotropical region and has never been used as a tool to analyze the actual conditions of aquatic environments particularly in the Subtropical Atlantic Forest, which occurs in south of Brazil. A systematic survey was carried out in aquatic systems located at remnants of forest from March 2011 to February 2012. A total of 565 specimens belonging to 34 species, distributed in 5 families were sampled. Libellulidae was dominant, with 14 species, followed by Coenagrionidae, Gomphidae, Lestidae and Aeshnidae. Through inventory survey we deepen the Odonata composition knowledge and performed a statistic analysis.

  • 39.
    Renner, Samuel
    et al.
    Laboratório de Ecologia e Evolução, Universidade do Vale do Taquari – Univates, Lajeado, Brazil.
    Périco, Eduardo
    Laboratório de Ecologia e Evolução, Universidade do Vale do Taquari – Univates, Lajeado, Brazil.
    Dalzochio, Marina S.
    Laboratório de Ecologia e Evolução, Universidade do Vale do Taquari – Univates, Lajeado, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Ecoregions within the Brazilian Pampa biome reflected in Odonata species assemblies2019Ingår i: Austral ecology (Print), ISSN 1442-9985, E-ISSN 1442-9993, Vol. 44, nr 3, s. 461-472Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Based on vegetation composition, previous studies of the Pampa biome in southern Brazil have defined seven ecoregions within the area. Here, we test this ecoregion approach studying the semi-aquatic insect group Odonata in five of these regions, aiming at comparing the ecoregions to the more traditional environmental predictors of water quality and land cover. Based on a data set of occupancy comprising 99 species distributed between 131 localities, a one-way Permutational Multivariate Analysis of Variance was used to compare differences in the species composition between the ecoregions, followed by a Principal Component Analysis to visualize the variation. The composition varied significantly between all groups tested, and the ordination explained 61.8% of the variance. A partial redundancy analysis of ecoregions, land cover and water quality variables explained 71% of the variance in Odonata community structure. Ecoregion was the most important predictor, followed by water quality and land cover. Within these species assemblies, we could select certain species that were representative of a given ecoregion, to which their distribution within the Pampa biome was entirely or mainly confined. Of 24 representative species 41.7% were rare, while the rest were more abundant and, hence, easier to detect. We suspect that the differences found between the Pampa ecoregions might be due to geology, as such factors may be strong determinants of biodiversity. Specific ecological requirements at the family and genus levels also seemed to act selectively on the species compositions within the ecoregions. Today, the Pampa is highly fragmented due to agricultural activities such as rice cultivation, extensive cattle farming and forest plantations. We suggest that an ecoregion-based approach to the implementation of conservation measures may be the best way to help these distinct species assemblies survive. © 2018 Ecological Society of Australia

  • 40.
    Renner, Samuel
    et al.
    Universidade do Vale do Taquari, Bairro Universitário, Lajeado, RS, Brazil.
    Périco, Eduardo
    Universidade do Vale do Taquari, Bairro Universitário, Lajeado, RS, Brazil.
    Ely, Gerson
    Universidade do Vale do Taquari, Bairro Universitário, Lajeado, RS, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Preliminary dragonfly (Odonata) species list from the Pampa biome in Rio Grande do Sul, Brazil, with ecological notes for 19 new records for the state2017Ingår i: Biota Neotropica, ISSN 1806-129X, E-ISSN 1676-0611, Vol. 17, nr 4, artikel-id e20170374Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An inventory of Odonata was carried out in the southern half of the state of Rio Grande do Sul, Brazil, in the Pampa biome. Originally, this biogeographical region was covered mostly by open fields and grassland, with sections of higher vegetation surrounding water bodies and rocky hills. Today the landscape is fragmented due to agricultural activities, mainly cattle farming, rice crops and forest plantations. Our survey was conducted in three municipalities from this region, between March 2015 and April 2016. Aiming at a general overview of the species composition, our sampling sites were selected on a wide basis, including lakes, bogs, temporary water bodies, small streams and river sections. Eighty two species of Odonata were collected comprising 40 genera and seven families. The dominant families were Libellulidae (56,1%), Coenagrionidae (24,5%) and Aeshnidae (7,3%). We found a diverse odonate assemblage, adding 19 new species records for the state of Rio Grande do Sul.

  • 41.
    Renner, Samuel
    et al.
    Lab de Evolução e Ecologia, Centro Universitário Univates, Lajeado, RS, Brazil.
    Périco, Eduardo
    Lab de Evolução e Ecologia, Centro Universitário Univates, Lajeado, RS, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Effects of exotic tree plantations on the richness of dragonflies (Odonata) in Atlantic Forest, Rio Grande do Sul, Brazil2016Ingår i: International Journal of Odonatology, ISSN 1388-7890, Vol. 19, nr 4, s. 207-219Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the forest types occurring in Southern Brazil is the mixed ombrophilous forest (MOF), a subtype of the Atlantic Forest, which is one of the richest biomes on Earth. This biome currently remains as a highly fragmented mosaic, under pressure from human development. The diversity and ecology of most animal groups in this biome are poorly known. We studied Odonata in a large forest fragment, including an ecological reserve: the Floresta Nacional de São Francisco de Paula (FLONA-SFP), in Rio Grande do Sul, administrated by the Brazilian government. The reserve is dominated by MOF with sectors of Pinus elliottii and Araucaria angustifolia. Three surveys of these forest sectors over one year yielded 42 species, with the highest species richness recorded in the P. elliottii sector. The odonate species recorded here are all generalist in terms of habitat preferences, but they appeared only in low numbers and were very particular in their occurrence pattern. We therefore assume that the introduction of an alien element in the Atlantic Forest has given rise to a new species assemblage, where the ecology of the species is adapted to the novel habitat of Pinus plantations. As expected, the species occurring in the MOF sectors were mainly habitat specialists. The Araucaria plantations had an intermediate species composition. Despite the differences observed in habitat preference between generalist and specialist species, such exotic plantation habitats may act as a temporary biodiversity reservoir for further habitat colonization. © 2016 Worldwide Dragonfly Association

  • 42.
    Renner, Samuel
    et al.
    Ecologia e Sensoriamento Remoto, Centro Universitário Univates, Lajeado-RS, Brasil.
    Périco, Eduardo
    Ecologia e Sensoriamento Remoto, Centro Universitário Univates, Lajeado-RS, Brasil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Man-made lakes form species-rich dragonfly communities in the Brazilian Atlantic Forest (Odonata)2016Ingår i: Odonatologica, ISSN 0375-0183, Vol. 45, nr 3-4, s. 135-154Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    One of the forest types occurring in Southern Brazil is the Mixed Ombrophilous Forest (MOF), a subtype of the Atlantic Forest and one of the biodiversity hotspots on Earth. We sampled adult Odonata at 30 locations in the Floresta Nacional de São Francisco de Paula (FLONA-SFP), Rio Grande do Sul, Brazil, a national reserve which is divided into several sectors of MOF, planted Araucaria angustifolia, Pinus elliottii used for sustainable and financial purposes, and open fields. There are three types of aquatic environments in the reserve: lakes, swamps, and rivers/streams. Our aim was to obtain an overview of the species’ distribution patterns in the three types of aquatic environments and to evaluate the species occurring in lakes, an exclusively man-made habitat in this area. We recorded 46 species from seven odonate families; 25 species (x = 5.71 ± 1.77 SD) occurring in rivers/ streams, 24 in lakes (11.57 ± 2.15) and 21 in swamps (5.22 ± 3.60). Using Non-metric Multidimensional Scaling (NmDS), we showed that the species composition differed clearly between the three types of aquatic habitats. While swamps and rivers/streams had a relatively similar and uniform species composition, species in the lakes were more varied but the total species number was almost as high as that of the rivers/streams. The lake communities also differed distinctly from those of the other habitats, and we assume that the lake species originate from other degraded areas in the vicinity, indicating that the remains of the Atlantic Forest has already been strongly altered by humans. Given the poor knowledge of the Odonata in the Atlantic Forest/MOF, we hope that our study may increase the understanding of the communities, and contribute to the development of conservation measures for this fragmented biome.

  • 43.
    Renner, Samuel
    et al.
    Universidade do Vale do Taquari, Lajeado, Brazil.
    Périco, Eduardo
    Universidade do Vale do Taquari, Lajeado, Brazil.
    Schmidt Dalzochio, Marina
    Universidade do Vale do Taquari, Lajeado, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Water body type and land cover shape the dragonfly communities (Odonata) in the Pampa biome, Rio Grande do Sul, Brazil2018Ingår i: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 22, nr 1, s. 113-125Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The biogeographical region known as the Pampa biome in southern Brazil, was originally mainly covered with open fields or grassland, with areas of riparian forest surrounding the water bodies. Today this landscape appears highly fragmented due to agricultural activities such as rice cultivation, extensive cattle farming, and forest plantations. Studies have shown that the Pampa biome has high levels of biodiversity and endemism, but with regard to invertebrates, this biome is still one of the least known in Brazil. We therefore designed a study comparing the dragonfly (Odonata) communities to environmental and landscape features in this area, measuring diversity by species richness, relative abundance and Shannon index. Our results showed that the Pampa is a biome very rich in odonates, and that the species communities are highly dependent on the environmental conditions of the area. Habitats such as Rivers/Streams, bordered by native grasslands and riparian forests, were shown to harbour communities that were ecologically more complex and sensitive than other habitat types. Man-made lakes and agricultural areas displayed lower levels of biodiversity and odonate communities dominated by generalist species. By combining data on the communities of Odonata and other taxa, our analyses may be instrumental in determining priority areas for future conservation measures within the area. © 2018, Springer International Publishing AG, part of Springer Nature.

  • 44.
    Renner, Samuel
    et al.
    Lab de Evolução e Ecologia, Centro Universitário Univates, Lajeado, RS, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Périco, Eduardo
    Lab de Evolução e Ecologia, Centro Universitário Univates, Lajeado, RS, Brazil.
    Testing Dragonflies as Species Richness Indicators in a Fragmented Subtropical Atlantic Forest Environment2015Ingår i: Neotropical Entomology, ISSN 1519-566X, E-ISSN 1678-8052, Vol. 45, nr 3, s. 231-239Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We surveyed 15 bodies of water among remnants of the Atlantic Forest biome in southern Brazil for adult dragonflies and damselflies to test whether an empirical selection method for diversity indicators could be applied in a subtropical ecosystem, where limited ecological knowledge on species level is available. We found a regional species pool of 34 species distributed in a nested subset pattern with a mean of 11.2 species per locality. There was a pronounced difference in species composition between spring, summer, and autumn, but no differences in species numbers between seasons. Two species, Homeoura chelifera (Selys) and Ischnura capreolus (Hagen), were the strongest candidates for regional diversity indicators, being found only at species-rich localities in our surveyed area and likewise in an undisturbed national forest reserve, serving as a reference site for the Atlantic Forest. Using our selection method, we found it possible to obtain a tentative list of diversity indicators without having detailed ecological information of each species, providing a reference site is available for comparison. The method thus allows for indicator species to be selected in blanco from taxonomic groups that are little known. We hence argue that Odonata can already be incorporated in ongoing assessment programs in the Neotropics, which would also increase the ecological knowledge of the group and allow extrapolation to other taxa. © 2015, Sociedade Entomológica do Brasil.

  • 45.
    Sahlén, Göran
    et al.
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Bio- och miljösystemforskning (BLESS).
    Bernard, Rafal
    Department of General Zoology, Adam Mickiewicz University, Poznan, Poland.
    Rivera, Adolfo Cordero
    Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, EUET Forestal, Campus Universitario, Pontevedra, Spain.
    Ketelaar, Robert
    Dutch Butterfly Conservation / Dutch Society for the Preservation of Nature, Eindhoven, The Netherlands.
    Suhling, Frank
    Institute of Geoecology, Dpt of Environmental System Analysis, Technical University of Braunschweig, Braunschweig, Germany.
    Critical species of Odonata in Europe2004Ingår i: International Journal of Odonatology, ISSN 1388-7890, Vol. 7, nr 2, s. 385-398Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The status of the odonate fauna of Europe is fairly well known, but the current IUCN Red List presents only six species out of ca 130, two of which are actually out of danger today. In this paper we propose a tentative list of 22 possibly declining or threatened species in the region. For the majority, reliable data of population size and possible decline is still lacking. Also 17 endemic species are listed, most occurring in the two centres of endemism in the area: the south-eastern (mountains and islands) and the western Mediterranean. These species should receive extra attention in future updates of the world Red List due to their limited distribution. The extreme variation in biomes and the human exploitation of habitats make conservation planning complicated in Europe. Within the EU, the FFH directive is a working tool aiding conservation. However, the species included do not fully correspond to those on the current Red List, nor to those discussed in this paper. We believe that future conservation efforts should focus on the most valuable and threatened habitats in each sub-region. Active conservation measures could be implemented on a European scale, provided that research will establish a solid ground for such measures. © 2004 Taylor & Francis Group, LLC.

  • 46.
    Sahlén, Göran
    et al.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS).
    Kalkman, Vincent J.
    Boudot, Jean-Pierre
    Bernard, Rafał
    Conze, Klaus-Jürgen
    De Knijf, Geert
    Dyatlova, Elena
    Ferreira, Sónia
    Jovic, Miloš
    Ott, Jürgen
    Riservato, Elisa
    European Red List of Dragonflies2010Rapport (Övrigt vetenskapligt)
    Abstract [en]

    The European Red List is a review of the conservation status of c.6,000 European species (mammals, reptiles, amphibians, freshwater fishes, butterflies, dragonflies, and selected groups of beetles, molluscs, and vascular plants) according to IUCN regional Red Listing guidelines. It identifies those species that are threatened with extinction at the regional level – in order that appropriate conservation action can be taken to improve their status. This Red List publication summarises results for European Dragonflies.

  • 47.
    Schmidt Dalzochio, Marina
    et al.
    Ecology and Evolution, University of Vale do Taquari, UNIVATES, Lajeado, Brazil.
    Périco, Eduardo
    Ecology and Evolution, University of Vale do Taquari, UNIVATES, Lajeado, Brazil.
    Renner, Samuel
    Ecology and Evolution, University of Vale do Taquari, UNIVATES, Lajeado, Brazil.
    Sahlén, Göran
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap, Rydberglaboratoriet för tillämpad naturvetenskap (RLAS).
    Effect of tree plantations on the functional composition of Odonata species in the highlands of southern Brazil2018Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 808, nr 1, s. 283-300Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Changes in biodiversity have mainly been assessed using taxonomical diversity indices. Although these approaches contribute to the scientific understanding of species richness and composition patterns, trait-based metrics may be more useful for detecting responses to land use change. We used odonates as a model system to compare traits composition in mixed ombrophilous forest (MOF) and tree plantations: exotic species (Pinus sp.) and native species (Araucaria angustifolia). Our goal was to understand and compare how each vegetation type affects the selection of species traits, and which factors are responsible for the presence of the species in the environment. We recorded 36 Odonata species distributed across 14 functional groups. The functional composition varied between MOF and exotic tree plantations and was similar between these two habitats and native tree plantations. Native forest favoured specialist traits. Our results suggest that the conversion of MOF to tree plantations, especially exotic ones, results in a shift to less specialized Odonata communities with altered functional group composition. This result highlights the negative impact associated with the conversion of native forests into exotic plantations. Our results show that odonates with specialist traits are limited to natural forest sites, which makes the conservation of such areas crucial. © 2017 Springer International Publishing AG, part of Springer Nature

  • 48.
    Skoglund, Linda
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET).
    Artsamhällen av trollsländor (Odonata) i norrländska tjärnar: identifiering av möjliga indikatorarter för artmångfald2014Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A field study of dragonfly larvae was performed in 20 lakes situated in boreal forest in northern Sweden (in the southeast of Norrbotten county), accompanied by the study of several habitat variables within the locales; fish presence, composition of water vegetation, forestry and the distribution of Sphagnum moss. None of these variables had a proven effect on the species composition of Odonata. This may be due to the fact that species occurring in the north part of the country are generally more tolerant to environmental variables compared to species with a more southern focus of distribution. A shorter growth season implies prolonged life cycles and should in all probability bring about a greater need for habitat tolerance. When a species occurrence is not strictly random the species richness within a region increases/decreases as a result of the presence/absence of specific species which are sensitive to particular variables in their surroundings (deconstructive approach to species richness). Indicator species (indicating general species richness) were distinguished by implementing an analysis of nestedness and the result was compared to a similar study conducted for central Sweden (Sahlén and Ekestubbe, 2001). E. najas and L. quadrimaculata came forth as suitable indicator species for northern boreal freshwater habitats in this study. In the north they displayed specialist tendencies and were highly selective in their choice of habitats. The same species appears in a very different ecological context when localized to southern Sweden where they are considered trivial species. In addition, temporal follow-ups (repeated stocktakings) of the species composition of small freshwater habitats in this region, and the establishment of accompanying nestedness matrices will allow for the detection of ecological shifts within particular species. These would indicate ongoing restructuring of the Odonate communities and yield information about the impact of climate change.        

  • 49.
    Skrijelj, Lejla
    Högskolan i Halmstad, Akademin för ekonomi, teknik och naturvetenskap.
    Population dynamics and management strategies of stray and free-ranging dogs in Bor, Serbia2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Hundar är en av de mest spridda karnivorerna och det tredje mest invasiva däggdjuret, efter katter och gnagare. Gatuhundar påverkar vilda djur negativt genom predation, störning, spridning av sjukdomar, konkurrens och hybridisering med andra vilda hunddjur. Även i urbana miljöer har gatuhundar en negativ påverkan, genom störning, förorening, trafikolyckor, bett och sjukdomsrisk. Serbien är ett av många länder i Balkanregionen som har för stora populationer av gatuhundar. I detta arbete undersöks populationsdynamiken hos gatuhundar i Bor, Serbien och diskuterar olika metoder för att hantera gatuhundpopulationen. Totalt inventerades 361 gatuhundar, 111 hanar, 85 honor och 165 med obestämt kön. 55 hundar (15.23%) uppskattades vara äldre än 7 år, 262 hundar (72.57%) uppskattades vara mellan 3-7 år, 30 hundar (8.31%) uppskattades vara mellan 6-24 månader gamla och 14 hundar (3.87) uppskattades vara mellan 0-6 månader gamla. Inga hundar visade tecken på rabies eller CDV (canine distemper virus) och 241 gatuhundar (66.75%) föreföll friska. Däremot visade 120 hundar (33.25%) någon typ av nedsatt hälsa. För att uppnå ett stopp i populationsökningen krävs minst 70% steriliseringstakt samt att man lär ut ansvarsfullt hundägande. Gatuhundarna visade olika reaktioner mot människor, 164 hundar (45.42%) var neutrala och 100 hundar (27.70%) visade ingen rädsla eller aggression för människor och interagerade gärna. Eftersom gatuhundarna är lättillgängliga, skulle de kunna ingå i populationshanteringar som TNR (trap-neuter-release) och hanhundar bör prioriteras med tanke på deras spridningsmönster.

  • 50.
    Strand, John A.
    et al.
    Limnology, Lund University, Lund, Sweden.
    Weisner, Stefan
    Limnology, Lund University, Lund, Sweden.
    Wave exposure related growth of epiphyton: Implications for the distribution of submerged macrophytes in eutrophic lakes1996Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 325, nr 2, s. 113-119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The distribution of submerged macrophytes in eutrophic lakes has been found to be skewed towards sites with intermediate exposure to waves. Low submerged macrophyte biomass at exposed sites has been explained by, for instance, physical damage from waves. The aim of this study was to investigate if lower biomass at sheltered sites compared to sites with intermediate exposure to waves can be caused by competition from epiphyton. Investigations were performed in eutrophic lakes in southern Sweden. Samples of submerged macrophytes and epiphytic algae on the macrophytes were taken along a wave exposure gradient. The amount of epiphyton (AFDW) per macrophyte biomass decreased with increased exposure. Biomass of submerged macrophytes, on the other hand, increased with increased exposure until a relatively abrupt disappearance of submerged vegetation occurred at high exposures. Production of epiphytic algae was monitored on artificial substrates from June to September at a sheltered and an exposed site in three lakes. It was higher at sheltered sites compared with exposed sites. We suggest that epiphytic algae may be an important factor in limiting the distribution of submerged macrophytes at sheltered sites in eutrophic lakes.

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