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213 Uppsatser om Key habitat - Sida 5 av 15
En uppföljning av floran i Enköpings vattenpark : kan anlagda våtmarker med vattenrening som huvudsyfte bidra till naturvård och biologisk mångfald?
Wetlands are important ecosystems and form habitat for both common and threatened species. In Sweden, as well in many other places on earth, there is a lack of wetlands. There is an expressed will to adjust this lack through restoration of wetlands with reduced function and through construction of new wetlands. Follow-ups and evaluations are important steps to optimize these actions. The wetland Vattenparken was constructed 1999 ? 2000 for treatment of surface water.
Jordlöparfaunan i bestånd av contortatall (Pinus contorta) och svensk tall (P. sylvestris) 1987 och 2010
In the 1970´s the North American lodgepole pine (Pinus contorta) was introduced to Sweden in large scale. The lodgepole pine affects its new environment different from Scots pine (P. sylvestris), leading to a change in biological diversity.
Forestry today affects the ground beetle fauna (Carabidae). Habitat specialists associated with older forests are first affected. When the canopy closes again after a clear-cutting species that prefer open habitats reduces and those who prefer mature/closed forests increase.
In this study we compare differences in diversity and community structure of ground beetles in stands of lodgepole pine and Scots pine.
Renar och klövvilt på järnvägar : en studie i järnvägars effekter på ren, älg och rådjur i norra och mellersta Sverige under 2005
Roads and railroads have significant impact on the surrounding landscape and the wildlife living in it. This study aims to provide an overview of the effects caused by railways to reindeer, roe deer and moose in Sweden in order to make more detailed assessments within this topic in the future. The method used is a study of literature on the subject and a synthesis of databases with information about wildlife mortalities, traffic intensity and fences in the study area; northern and central Sweden. The databases were used to compile digital maps using ArcGIS.
Infrastructure brings change to the surrounding landscape and its function as habitat for wildlife. Railroads cause barrier effects such as fragmentation, wildlife mortality, loss of habitat and loss of connectivity.
Habitat preferences and reproductive success forthe threatened longhorn beetle Plagionotusdetritus
Plagionotus detritus is a threatend longhorn beetle that only exists at one site in Sweden. It is saproxylic and depending on recently dead coarse oak wood for its larval development. Trees at Djurgården, Stockholm that have been colonized by Plagionotus detritus has been studied to find out the habitat preferences of the species and to see what affects the density of beetles in a tree. The bark of some trees and wood from the breeding project at Nordens Ark has also been studied to find out what affects the species reproductive success. The reproductive success was measured in two ways, the larval mortality and the size of the hatching holes.
Betydelsen av skogens ålder och förekomst av lavar för renars val av vinterbetesområde :
This is a study on winter groups, ?siida?, of semi-domesticated mountain-migrating reindeers that move to lichen pastures in the lowland boreal forests during winter. The aim of the study was to determine reindeer habitat use in their winter ranges in a managed forest landscape. The reindeers use of three different types of forests was determined, 1) 100-130 year old, 2) 20-40 year old forest and 3) clear-cut areas. All sites were dominated by Scots pine, Pinus sylvestris, and had the same types of ground vegetation.
Toppturer norr om Torneträsk
The demand of nature tourism is increasing and new ways to satisfy tourists are necessary.The goal with this report was to answer that demand by exploring the possibilities for backcountry skiing north of Torneträsk. This area was chosen because it is unexplored. This hasbeen succeeded by an extensive fieldwork. Aspects like topography, routes, slope angles andgeological places of interests where recorded. The results has shown that back country skiingis well suited for this area and poses no negative impact on the natural habitat.
Genflöde, hybridisering och sympatrisk artbildning - med strandsnäcka som exempel
Det finns idag en mängd olika artbegrepp men inget universellt som fungerar för alla organismer. Det mest använda är det biologiska artbegreppet som innebär att en art är en population organismer som är reproduktivt isolerade från andra populationer. De evolutionära processerna som leder till bildandet av nya arter delas upp beroende på vilken geografisk skala de utspelar sig i. Den allopatriska modellen som är den mest vedertagna innebär att geografiskt isolerade populationer med tiden ackumulerar genetiska, morfologiska eller beteendemässiga differentieringar till den grad att populationerna kan betraktas som olika arter. Sympatrisk artbildning är när artbildning sker inom ett och samma geografiska område, alltså utan geografisk isolering.
Bottensubstratets inverkan på föryngring av Flodpärlmussla
The freshwater pearl mussel (Margaritifera margaritifera) is threatened throughout its range. There has been a substantial decline of the species and one major reason is habitat degradation. We investigated how the substrate composition of the bottom floor affects the regeneration of the mussel by analyzing data from the Västerbotten County Board?s inventory of the freshwater pearl mussel. The results implied that fine material such as fine sediment and sand might be detrimental to regeneration whereas gravel and boulders and in particular stone seem to be beneficial.
Större svartbagge Upis ceramboides i norra Hälsingland : förekomst, substratkrav och effekter av skogsbrukets naturvårdsåtgärder
Many wood living insects are considered threatened by modern forestry due to the reduction in amount of dead wood. During the last decade various methods have been used to enhance the quantity of dead wood in managed forests. However little is known how and if these methods are aiding saproxylic insects. The threatened tenebrionid beetle, Upis ceramboides, is already extinct in southern Sweden. It develops in white rotted dead birch (Betula spp) and requires sun-exposed sites.
Förskolebarns kommunikation i leken : Lek, kommunikation och språk i sammanhang
The aim of this study is to observe Swedish preschool children in their natural habitat and without any intervention. Four different observations are made and thereafter analyzed. Throughout the whole study the subject of interest is the children's communication in their play. Children can communicate with each other in various ways, for instance with speech and without speech, i.e. with their physical language, aesthetic and multi language.
Utveckling i Ammerån : att skapa ett hållbart fiske med hög kvalitet
Ammerån which is a small forest river in eastern Jämtland is a well-known river that has been a popular fishing river for a long time. The actual Ammerån begins downstream the lake Solbergsvattnet at Hammerdal and flows into the Indalsälven 10 km upstream Hammarstrand. The river environment switches between forests with wilderness feeling and open agricultural land. The entire Ammerån is today a nature reserve and protected from hydropower development. Fishing in Ammerån has mainly been focused on trout and grayling, and is so even today.
Undervegetation : användning av vedartade marktäckare i anläggning
The use of the robust and durable woody ground covers is increasing, not in the least in public places. The group includes low shrubs of different height that effectively build low, tight vegetation that covers the ground. Despite all the good qualities the knowledge about them is quite low and there are ideas about them of being dull.
The woody ground covers manage to struggle against weeds effectively by competing for nourishment and water, but above all, by the canopy of the ground covers that prevent the weeds from getting enough light. In that way the woody groundcovers can effectively compete with the annual weeds.
Hur biodiversitet på ekosystemnivå skiljer sig mellan olika habitat
Biodiversity can be described as the total variation of life forms, where diversity ranges from gene level up to the ecosystem level. The diversity can be calculated in a number of ways, and this study use one of these methods. In this study empirical food webs have been used and analyzed, where eleven characters are defined and used as parameters to calculate the Euclidean distances between food webs that describe the variation that may exist within classes of terrestrial, marine and freshwater habitats. The class who stood out and showed the greatest diversity at the ecosystem level was the marine food webs, which showed a high value of the average euclidean distance. The other networks were not as distinctive and the average of the euclidean distance in these classes was comparatively low..
Dödlighet hos gepardungar
Geparder minskar i antal och dödligheten hos ungarna är väldigt hög. Syftet med denna litteratursstudie är att ta reda på varför gepardungar dör och vad som är de största orsakerna. Geparder är utsatta för predatorer på två sätt; rovdjur kan stjäla deras byten eller döda geparder. Därför är studien främst inriktad på vilda geparder.
Anatomin skiljer sig mellan geparder och andra kattdjur eftersom de är världens snabbaste landlevande däggdjur. De föder många ungar och har en hög reproduktionsförmåga.
Effekter av predationsrisk på sånglärkors (Alauda arvensis) habitatval på åkermark
Along with other European farmland birds, the skylark (Alauda arvensis) has declined rapidly since the 1970?s. Between 1975 and 2003, the Swedish population of skylarks declined with 64 %. In Britain, the decline is often explained by alterations in farming practices in general and the shift from spring-sown to winter-sown cereals in particular. The dense vegetation structure of winter cereals is limiting the number of breeding attempts possible, causing the entire population to decline.