title: Long-term consequences of disturbances on reproductive strategies of the rare epiphytic lichen Lobaria pulmonaria: clonality a gift and a curse.
abstract: The effect of disturbance on symbiotic organisms such as lichens is particularly severe. In case of heterothallic lichen-forming fungi, disturbances may lead to unbalanced gene frequency and patchy distribution of mating types, thus inhibiting sexual reproduction and imposing clonality. The impact of disturbance on reproductive strategies and genetic diversity of clonal systems has so far received little attention. To infer the effects of disturbances on mating-type allele frequencies and population structure, we selected three populations in the Parc Jurassien Vaudois (Switzerland), which were affected by uneven-aged forestry, intensive logging and fire, respectively. We used microsatellite markers to infer genetic diversity, allelic richness and clonal diversity of the epiphytic lichen Lobaria pulmonaria and used L. pulmonaria-specific MAT1-1 and MAT1-2 markers to analyse the frequency and distribution of mating types of 889 individuals. Our study shows that stand-replacing disturbances affect the mating-type frequency and distribution, thus compromising the potential for sexual reproduction. The fire-disturbed area had a significantly lower genetic and genotypic diversity and a higher clonality. Furthermore, the majority of compatible mating pairs in this area were beyond the effective vegetative dispersal range of the species. We conclude that stand-replacing disturbances lead to lower chances of sex and symbiont reshuffling and thus have long-lasting negative consequences on the reproductive strategies and adaptive potential of epiphytic lichen symbioses.
authors.affiliation: Department of Biological Sciences, Institute of Ecology, Evolution and Diversity, Goethe Universität, Max-von-Laue-Str. 13, D-60438 Frankfurt, Tel: +49 (0)69 7542 1851; Fax: +49 (0)69 7542 1800, Germany Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325 Frankfurt, Germany Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland garima.singh@senckenberg.de.
authors.forename: Garima
authors.initials: G
authors.lastname: Singh
authors.affiliation: Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Senckenberganlage 25, D-60325 Frankfurt, Germany.
authors.forename: Francesco
authors.initials: F
authors.lastname: Dal Grande
authors.affiliation: Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland Faculty of Life and Environmental Sciences, University of Iceland, Sturlugata 7, 101 Reykjavik, Iceland.
authors.forename: Silke
authors.initials: S
authors.lastname: Werth
authors.affiliation: Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, 8903 Birmensdorf, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Scheidegger
mesh_terms: D001203:Ascomycota / Q000235:genetics*; D005787:Gene Frequency; D049770:Genes, Mating Type, Fungal / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D008011:Lichens / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D012098:Reproduction; D013557:Switzerland; D013559:Symbiosis / Q000235:genetics
keywords: allelic richness; disturbance; genetic diversity; lichen-forming fungi; mating-type gene frequency; population structure