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Spatial Dynamics of Wetland Plant Populations: Reponses to Habitat Fragmentation and Land-Use Changes

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.

Thermal plasticity of Laminaria digitata - seasonal growth; recruitment; thermal physiology of juvenile sporophytes

We investigated effects of temperature during ontogeny of the kelp Laminaria digitata across haploid gametophyte and diploid sporophyte life cycle stages in 5 distinct genetic lines. We sampled meristematic discs from wild sporophytes on the island of Helgoland (North Sea; 54.1779 N, 7.8926 E) in May 2017, July 2017 and February 2018 and conducted a seasonal growth experiment at 5°C and 15°C over 14 days (experiment 1). Based on meiospores from five individuals (genetic lines) sampled in July 2017, we applied a full-factorial experimental design to generate different temperature histories by applying 5°C and 15°C during meiospore germination, gametogenesis of parental gametophytes and recruitment of offspring sporophytes (19-26 days; recruitment), and juvenile sporophyte rearing (91-122 days). We then tested for thermal plasticity among temperature history treatments at 5°C and 15°C in a final 12-day experiment assessing growth, the storage compound mannitol, carbon and nitrogen contents, and fluorometric responses in 3-4 month old sporophytes (experiment 2).

Conservation Genetics of the Bearded Vulture, Gypaetus

Reintroduction, i.e. the release of captive reared animals to the wild in an attempt to re-establish or augment a population, is an accepted tool in conservation of endangered species. Within the framework of the international project 'Reintroduction of the Bearded Vulture in the Alps' more than 60 captive reared birds were released since 1986 to reestablish the extinct population in the Alps. Because they are small, both the captive and the reintroduced population face the potentially disastrous risks of inbreeding and loss of genetic variability. To avoid inbreeding and to minimize the loss of genetic variability a genetic and demographic management is needed. Important information's for the planning and realization of such a management are the amount of genetic variability remaining in the captive and released populations, compared to large natural populations and the knowledge of the genealogical relationships among the individuals. In the project 'Reintroduction of the Bearded Vulture in the Alps' the genealogy of current individuals is available, but relationship among the 33 reproducing founders is almost completely unknown and there are no assessments of the genetic variability in natural and captive populations. The proposed project will provide the missing genetic data required for establishing a genetic management plan for the Bearded Vulture and will provide important tools for the long-term monitoring of the released population. In addition, the results gained in this study will improve Population Viability Analysis of Bearded Vulture populations. 1. Relatedness analysis of breeding network birds: Molecular genetic techniques (i.e micro satellites) will be used to provide information on the relative genetic similarity or distance among the founder individuals. 2. Comparison of genetic variability between natural populations and the breeding network: To determine whether there is a loss of genetic variability due to inbreeding and genetic drift, we will measure the genetic variability in both natural and captive populations of the Bearded Vulture using microsatelite markers. 3. Comparison of genetic variability between the original population in the Alps and the breeding network. All birds from the original population in the Alps are extinct.

Natuerliche Vielfalt in alpinen Waldoekosystemen: Analyse, Schutz und Bewirtschaftung^Natuerliche Vielfalt in alpinen Waldoekosystemen: Analyse, Schutz und Bewirtschaftung (FAIR FP4)^Biologische Vielfalt in alpinen Waldoekosystemen: Analyse, Schutz und Bewirtschaftung, BAFE: Biodiversity in Alpine Forest Ecosystems: Analysis, Protection and Management

Alpine forest ecosystems are increasingly threatened by environmental changes and are modified by forest management and land-use. Genetic diversity plays a major role in the sensitivity, stability and dynamics of ecosystems, because it determines the adaptive potential of species to changing environments. Until now there is a lack of genetic inventories in Alpine ecosystems. Our project focuses on carrier tree species in high elevated regions, adressing biodiversity in terms of genetic diversity within and between carrier species of Alpine forest ecosystems (Abies alba, Larix decidua, Picea abies, Pinus cembra, and Pinus mugo). Analyses of various molecular markers (isozymes, nuclear and chloroplast microsatellites, and a mitochondrial marker) will create a novel data pool in order to better understand the function and dynamics of ecosystems and to transfer results into practice. Species will be studied simultaneously along elevetional transects up to the timberline at 14 locations throughout the Alps.

Globale Klimaaenderung und Pflanzengemeinschaften

Das Projekt untersucht die Reaktion von Pflanzen und Pflanzengemeinschaften auf globale Klimaaenderungen. Es soll vor allem aufzeigen, mit welchen Anpassungen Pflanzen auf den steigenden Kohlendioxid-Gehalt (CO2-Gehalt) in der Luft reagieren und welche Pflanzenarten geeignete Indikatoren fuer solche Klimaaenderungen sind. Untersucht wird zum Beispiel, inwiefern die Reaktion von Pflanzenarten auf erhoehte CO2-Konzentrationen von deren genetischer Variabilitaet abhaengt und wie sich erhoehte CO2-Konzentrationen auf die Wechselbeziehungen zwischen Pflanzen und ihren Konkurrenten, Schaedlingen und Nuetzlingen auswirken. Fragestellungen: Reagieren genetisch verschiedene Individuen einer Pflanzenart (Genotypen) unterschiedlich auf eine erhoehte CO2-Konzentration? Inwiefern beeinflusst eine erhoehte CO2-Konzentration die Wechselbeziehungen zwischen dem Gras Bromus erectus und einerseits dem parasitischen Pilz Epichloe typhina oder andererseits der konkurrierenden Segge Carex flacca? Beeinflusst eine erhoehte CO2-Konzentration die Etablierung neuer Populationen verschiedener Pflanzenarten? Untersuchungsgegenstand: Versuchspflanzen sind derzeit die Aufrechte Trespe Bromus erectus und die blaugruene Segge Carex flacca . Einige Genotypen von Bromus erectus sind mit dem parasitischen Pilz Epichloe typhina infiziert. Abgeschlossen sind Untersuchungen an der Grossbluetigen Brunelle Prunella grandiflora und der Gewoehnlichen Brunelle Prunella vulgaris . Neu wird derzeit eine Untersuchung zur Etablierung von Populationen mit 20 Pflanzenarten durchgefuehrt. Untersuchungsgebiet: Die Experimente werden in Nenzlingen (Basler Jura) und Eschikon (Kanton Zuerich) durchgefuehrt. Untersuchungsmethoden: In Nenzlingen werden verschiedene Genotypen des Grases Bromus erectus in oben offenen Plastikkammern zum einen individuell, zum anderen im Magerwiesenbestand unter normaler oder erhoehter CO2-Konzentration gezogen. In einem zweiten Experiment sollen dieselben Genotypen mit oder ohne Infektion durch Epichloe typhina bei normaler oder erhoehter CO2-Konzentration direkt und ausschliesslich miteinander konkurrieren. In Eschikon wird die intra- und interspezifische Konkurrenzkraft von Bromus erectus und Carex flacca untersucht. Sie wurden in senkrecht aufeinander stehenden Dichtegradienten angepflanzt. Die Testpflanzen werden in Sommer und Herbst oberirdisch geerntet, die Anzahl der Triebe, Bluetenstaende uns Samen gezaehlt und die Biomasse gewogen. Ausserdem werden zum Teil die Qualitaet der Pflanzengewebe, die CO2-Assimilation und die Wasserabgabe unter verschiedenen Umweltbedingungen analysiert. Projektorganisation: Das Projekt ist Teil des integrierten Projektes Biodiversitaet (IP Biodiversitaet) und gehoert damit zum Schweizerischen Schwerpunktprogramm Umwelt (SPP-U). Die Experimente in Nenzlingen, die 1993 begonnen worden sind, werden in Zusammenarbeit mit dem Botanischen Institut der Universitaet Basel usw.

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