Description: Das Projekt "Spatial Dynamics of Wetland Plant Populations: Reponses to Habitat Fragmentation and Land-Use Changes" 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. lat-season mowing or extensive grazing. Agricultural practices in the past have led to a demise and fragmentation of fen areas. Even though protected by law the persistence of the remaining fens is still threatened by intensified farming (drainage, fertilization) or abandonment (cessation of mowing). The goal of this project is to investigate patterns of diversity and to develop conservation strategies. The following questions are asked: How do different agricultural practices, habitat fragmentation and altitude of the fens influence the diversity of mosses, higher plants and insects? Do the same factors also affect the morphology and the population structure of a typical fen plant species? How does productivity influence the vegetation composition and plant species richness of montane fen meadows? How does fertilization affect the competitive ability of selected plant species? Which conservation measures can protect the endangered montane fens? For the study we randomly selected 36 montane fens from the wetland inventory of Switzerland. For three altitude classes (800-1000 meters above sea level, 1000-1200 meters a.s.l. and 1200-1400 meters a.s.l.) 12 fens each were selected for our investigation, six of them mown once a year, six grazed by cattle's. Species diversity and -composition, vegetation structure, productivity and the population structure of single species were recorded for each of the 36 fens. The influence of nutrient inputs and habitat quality on the competitive ability of fen-species was assessed in a field-experiment. Previous results: Biodiversity of montane fen meadows is mainly influenced by the agricultural practices. Mown sites exhibit more species of vascular plants and butterflies than cattle-grazed areas, whereas grasshoppers prefer grazed sites with complex Vegetation structure. The species richness of vascular plants is closely related to the aboveground biomass. Highest diversity occurs at intermediate levels of bio-mass. High soil fertility reduces species richness. The diversity of mobile organisms such as butterflies not only depends on the habitat quality of the fen sites but additionally on that of the adjacent areas. Habitat fragmentation clearly reduces the diversity of all investigated organisms. In conclusion, only a diverse land-use can maintain the species diversity of different groups of organisms. Additionally, the remaining fen meadows have to be protected from fragmentation and nutrient influx.
SupportProgram
Origin: /Bund/UBA/UFORDAT
Tags: Schmetterling ? Insekt ? Hochmoor ? Vegetation ? Genetische Variation ? Mahd ? Moos ? Nährstoff ? Pflanzengesellschaft ? Wiese ? Schweiz ? Extensive Beweidung ? Bodenfruchtbarkeit ? Feuchtgebiet ? Landnutzungsänderung ? Gefährdete Arten ? Habitat ? Landwirtschaftliche Nutzung ? Niedermoor ? Pflanzenart ? Pflanzenbestand ? Konservierung ? Wirkungsanalyse ? Demografie ? Schutzmaßnahme ? Standortwahl ? Studie ? Dränung ? Düngung ? Meeresspiegel ? Pflanze ? Artenvielfalt ? Grundwasser ? Flächennutzung ? Beweidung ? Bewirtschaftungssystem ? Population ? Produktivität ? Landwirtschaft ? Biodiversität ? Persistenz ? abandonment ? mowing regime ? Biotopisolation ?
License: cc-by-nc-nd/4.0
Language: Englisch/English
Time ranges: 1994-01-01 - 2025-04-25
Accessed 1 times.