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The Global ETD Search service is a free service for researchers
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Showing 181 to 184 of 184 (0.032 seconds)Spelling suggestions: "subject:": biologisk mångfald"" "subject:": etiologisk mångfald""
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Variation i blomsterlupinens (Lupinus polyphyllus) tillväxt och fenologi i dess invasiva utbredningsområde i Europa / Variation in the growth and phenology of the garden lupin (Lupinus polyphyllus) in its invasive range in EuropeKaukoranta, Vilma January 2020 (has links)
Den invasiva blomsterlupinens (Lupinus polyphyllus) spridning i Sverige är ett hot mot många inhemska växtarters överlevnad. Det är oklart hur den pågående globala uppvärmningen kan komma påverka artens invasionsframgångar. I det här kandidatarbetet har jag därför studerat hur blomsterlupinens tillväxt och fenologi varierar längs latitud i Europa i syfte med att avgöra om arten visar fitnesskillnader beroende på temperatur. Tjugo populationer från Trier (Tyskland) i söder till Umeå (Sverige) i norr följdes under en växtsäsong och data på blomsterlupinplantornas höjd samt blomställningarnas längd samlades in. Regressionsanalysen visade att det inte fanns något signifikant skillnad mellan latitud och ovanjordisk biomassa eller blomställningens längd. Däremot utvecklades den reproduktiva biomassan tidigare i växtsäsongen i de lägre breddgraderna i Europa jämfört med de högre. Studien ger en indikation om att ett varmare klimat kan ha en viss positiv påverkan på blomsterlupinens reproduktion och spridning. De lokala mikroklimatiska effekterna verkar dock ha en stor påverkan på dess relativa fitness, vilket betyder att vissa populationer kan gynnas mer än andra. Utbredningsområdet kan komma utökas mer norrut när stigande temperaturer och färre frostdagar gör nya områden tillgängliga för arten. / The spread of the invasive garden lupin (Lupinus polyphyllus) in Sweden threatens the survival of many native plant species. It is unclear how ongoing global warming may affect the species' invasion success. In this Bachelors essay I have therefore studied how the growth and phenology of the garden lupin varies with latitude in Europe to determine if the species shows any fitness differences depending on the temperature. Twenty garden lupin populations from Trier (Germany) in the south to Umeå (Sweden) in the north were followed during a single growing season and data on the plant’s height and the length of the inflorescences were collected. Regression analysis showed that there was no relationship between latitude and aboveground biomass or length of inflorescence. Reproductive biomass, on the other hand, developed earlier in the growing season at lower latitudes than at higher ones. The study indicates that a warmer climate may have a positive effect on the reproduction and spread of the garden lupin. Local microclimatic effects appear to have a major impact on its relative fitness though, which means that some populations may benefit more than others. The species’ range may expand further north as rising temperatures and fewer frost days make new areas available for the species.
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Betesrestaureringens effekter på växtartrikedom och biologisk mångfald : -restaurering av betesmark på Hallands Väderö / Effects of grassland restoration on plant species richness and biodiversity : -pasture restoration on Hallands VäderöYlva, Rolfsdotter Söderberg January 2024 (has links)
Abstract Pasture is a very species-rich but threatened nature type, and compared to 200 years ago, only five percent of natural pastures remain in Sweden. One way to try to save the biological diversity that pastures harbor is to restore overgrown land by clearing and reintroducing grazing animals. At the site chosen for this study, Hallands Väderö, 92 ha of pasture have been restored during less than ten years. The purpose of this thesis is to compare species richness in vegetation on recently restored land (cleared 2-10 years ago), land that has been grazed continuously for a long time and overgrown pasture, and to investigate whether the number of plant species increases with time after a pasture restoration. Thirteen locations on the island were selected, and three randomly selected square meter squares per area were inventoried. Each area was then searched for more species that were not present in the random squares. The data underwent analysis using regression analysis, ANOVA and Tukey test. Results indicated no significant relationship between the number of species in an area and the time (years) after a restoration. The Tukey test indicated that the biological diversity (effective number of species) was statistically significant higher on continuously grazed areas than on overgrown areas and that the number of species was statistically significant higher on restored areas than on overgrown areas. This means that there is an effect of the management; the number of species increases after grazing restoration, and biodiversity is higher on continuously grazed land than on overgrown land. The fact that the overgrown pasture has the lowest number of species shows that we risk losing species if pastures are abandoned and overgrown. / Sammanfattning Betesmark är en väldigt artrik men hotad naturtyp och jämfört med för 200 år sedan finns endast fem procent av naturbetesmarkerna i Sverige kvar. Ett sätt att försöka bibehålla den biologiska mångfalden, som betesmark hyser, är att restaurera igenväxt mark genom röjning och återintroduktion av betesdjur. På den valda platsen för denna studie, Hallands Väderö, har 92 ha mark betesrestaurerats under knappt tio års tid. Syftet med detta examensarbete är att jämföra artrikedom i växtligheten på nyligen restaurerad mark (röjd för 2–10 år sedan), mark som betats kontinuerligt under lång tid och igenväxt betesmark samt att undersöka om antalet växtarter ökar med tiden efter en betesrestaurering. Tretton platser på ön valdes ut och tre slumpvis valda kvadratmeterstora rutor per område inventerades. Varje område genomsöktes sedan efter fler arter som inte fanns i de slumpade rutorna. Datan analyserades med regressionsanalys, ANOVA och Tukey-test. Resultatet visade att det inte fanns något signifikant samband mellan antal arter på ett område och tiden (år) efter en restaurering. Tukey-testet visade att den biologiska mångfalden (effektivt artantal) var statistiskt signifikant högre på kontinuerligt betade områden än igenväxta områden och att antal arter är statistiskt signifikant fler på restaurerade områden än igenväxta områden. Detta betyder att det finns en effekt av skötseln; antal arter ökar efter en betesrestaurering och den biologiska mångfalden är högre på kontinuerligt betad mark än igenväxt mark. Att den igenväxta betesmarken har lägst antal arter visar på att vi riskerar att förlora arter om betesmarker överges och växer igen.
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Network Based Tools and Indicators for Landscape Ecological Assessments, Planning, and DesignZetterberg, Andreas January 2009 (has links)
<p>Land use change constitutes a primary driving force in shaping social-ecological systems world wide, and its effects reach far beyond the directly impacted areas. Graph based landscape ecological tools have become established as a promising way to efficiently explore and analyze the complex, spatial systems dynamics of ecological networks in physical landscapes. However, little attention has been paid to making these approaches operational within ecological assessments, physical planning, and design. This thesis presents a network based, landscape-ecological tool that can be implemented for effective use by practitioners within physical planning and design, and ecological assessments related to these activities. The tool is based on an ecological profile system, a common generalized network model of the ecological infrastructure, graph theoretic metrics, and a spatially explicit, geographically defined representation, deployable in a GIS. Graph theoretic metrics and analysis techniques are able to capture the spatio-temporal dynamics of complex systems, and the generalized network model places the graph theoretic toolbox in a geographically defined landscape. This provides completely new insights for physical planning, and environmental assessment activities. The design of the model is based on the experience gained through seven real-world cases, commissioned by different governmental organizations within Stockholm County. A participatory approach was used in these case studies, involving stakeholders of different backgrounds, in which the tool proved to be flexible and effective in the communication and negotiation of indicators, targets, and impacts. In addition to successful impact predictions for alternative planning scenarios, the tool was able to highlight critical ecological structures within the landscape, both from a system-centric, and a site-centric perspective. In already being deployed and used in planning, assessments, inventories, and monitoring by several of the involved organizations, the tool has proved to effectively meet some of the challenges of application in a multidisciplinary landscape.</p>
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Network Based Tools and Indicators for Landscape Ecological Assessments, Planning, and DesignZetterberg, Andreas January 2009 (has links)
Land use change constitutes a primary driving force in shaping social-ecological systems world wide, and its effects reach far beyond the directly impacted areas. Graph based landscape ecological tools have become established as a promising way to efficiently explore and analyze the complex, spatial systems dynamics of ecological networks in physical landscapes. However, little attention has been paid to making these approaches operational within ecological assessments, physical planning, and design. This thesis presents a network based, landscape-ecological tool that can be implemented for effective use by practitioners within physical planning and design, and ecological assessments related to these activities. The tool is based on an ecological profile system, a common generalized network model of the ecological infrastructure, graph theoretic metrics, and a spatially explicit, geographically defined representation, deployable in a GIS. Graph theoretic metrics and analysis techniques are able to capture the spatio-temporal dynamics of complex systems, and the generalized network model places the graph theoretic toolbox in a geographically defined landscape. This provides completely new insights for physical planning, and environmental assessment activities. The design of the model is based on the experience gained through seven real-world cases, commissioned by different governmental organizations within Stockholm County. A participatory approach was used in these case studies, involving stakeholders of different backgrounds, in which the tool proved to be flexible and effective in the communication and negotiation of indicators, targets, and impacts. In addition to successful impact predictions for alternative planning scenarios, the tool was able to highlight critical ecological structures within the landscape, both from a system-centric, and a site-centric perspective. In already being deployed and used in planning, assessments, inventories, and monitoring by several of the involved organizations, the tool has proved to effectively meet some of the challenges of application in a multidisciplinary landscape.
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