Sökning: "ekosystemtjänster"
Visar resultat 21 - 25 av 26 avhandlingar innehållade ordet ekosystemtjänster.
21. Ecological interactions in human modified landscapes : Landscape dependent remedies for the maintenance of biodiversity and ecosystem services
Sammanfattning : Modern agricultural practices have led to an intensification of the agricultural landscape which has negatively affected both biodiversity and the ecosystem services it provides. In my thesis I have used ecological theory of optimal foraging to try and explain how landscape structure, landscape composition and agricultural management can explain the loss of biodiversity and how remedies can efficiently be implemented. LÄS MER
22. Effects of landscape context on populations of bumblebees
Sammanfattning : To investigate recent declines in bumblebee populations, I carried out landscape analyses, made field studies of bumblebees, flowering plants and pollination in an agricultural region in southernmost Sweden. Studies were carried out in landscapes of contrasting agricultural intensity and land-cover configuration; "simple" landscapes highly dominated by large crop fields, and "complex" with mixed farming, grasslands and smaller fields. LÄS MER
23. Biodiversity in Agricultural Landscapes: Landscape and Scale-Dependent Effects of Organic Farming
Sammanfattning : Declines in the distribution and abundance of many farmland species during recent decades have been attributed to agricultural intensification. Agri-environment schemes are commonly used in Europe to reduce this loss of farmland biodiversity, but their effectiveness may depend on several external factors. LÄS MER
24. Conservation of semi-natural grasslands : Effects of different management methods on biodiversity
Sammanfattning : Species-rich semi-natural grassland are valuable habitats in the agricultural landscape as they may contain a high diversity of both plant and animal species, as well as provide essential ecosystem services like pollination. To keep these habitats open and to maintain the biodiversity in them, management like grazing or mowing is necessary. LÄS MER
25. Small biotopes: Landscape and management effects on pollinators
Sammanfattning : The intensification of agriculture during the second half of the twentieth century, has caused sever declines of farmland biodiversity, where loss of semi-natural habitats is one of the major drivers. To halt further loss of habitat and biodiversity, agri-environmental schemes (AES) are used to compensate farmers to use methods less harmful to the environment. LÄS MER