Description: Das Projekt "Response of Fen Plants to Habitat Fragmentation and Abandonment: Demographic and Genetic Variation in Space and Time" wird/wurde gefördert durch: Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung. Es wird/wurde ausgeführt durch: Universität Zürich, Institut für Umweltwissenschaften.Fen meadows belong to the few remaining semi-natural plant communities with high species diversity and a high proportion of rare and endangered species. They are influenced by groundwater or aquifer discharge. Their existence depends on continued but low-intensity agricultural use, i.e. late-season mowing or extensive grazing. Agricultural practices in the past have led to a demise and fragmentation of fens. Even though protected by law the persistence of the remaining fens is still threatend by intensified farming (drainage, fertilization) or abandonment (cessation of mowing). In this project two crucial, interconnected issues, namely the consequences of fragmentation of intact fens and of abandonment are adressed. A novel approach, which incorporates the spatial structure of several populations of abundant species, will be used. We will examine their genetic and demographic population structure as a function of management history. Subproject I: Effects of habitat fragmentation on species persistence. The spatial requirements for species persistence in intact fens will be examined in five fen systems, composed of extensive mainlands and associated sites differing in the extent of spatial isolation. We will test whether habitat fragmentation leads to a decline in genetic variation and vitality of abundant species, and to what extent dispersal and colonization ability influence regional population dynamics. Subproject II: Effects of abandonment and associated successional changes on species persistence. The effects of abandonment (cessation of mowing) and associated successional changes on populations of the four species will be examined by constructing a chronosequence of abandonment consisting of roughly 20 abandoned fens. Hypothesized reductions in genetic variation and vigour (size, structure, growth) on abandoned sites will be studied in relation to nearby intact fens. In addition, the possibility of revitalizing populations in abandoned fens will be assessed by experimental mowing.
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Populationsdynamik ? Landschaftsschaden ? Vegetationsdynamik ? Genetische Variation ? Moor ? Pflanzengesellschaft ? Wiese ? Genetische Ressourcen ? Extensive Beweidung ? Gefährdete Arten ? Habitat ? Landwirtschaftliche Nutzung ? Niedermoor ? Pflanzenart ? Pflanzenbestand ? Renaturierung ? Grünlandwirtschaft ? Artengefährdung ? Artenbestand ? Artenvielfalt ? Demografie ? Standortwahl ? Grundwasser ? Weideland ? Persistenz ? Raumstruktur ? Standortbedingung ? Landwirtschaft ? Bewirtschaftungssystem ? Diversität ? Population ? Biodiversität ? Landschaftsnutzung ? Biotopisolation ? Genstabilität ? Inseleffekt [Ökologie] ? Landschaftsbelastung ? Arealveränderung ? Pflanzenwachstum ? abandonement ?
License: cc-by-nc-nd/4.0
Language: Englisch/English
Time ranges: 1997-10-01 - 2000-12-31
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