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Highly Fragmented Habitats (highly + fragmented_habitat)
Selected AbstractsMicrosatellite DNA markers for the snow vole (Chionomys nivalis)MOLECULAR ECOLOGY RESOURCES, Issue 3 2008P. WANDELER Abstract A total of 14 dinucleotide microsatellite loci were characterized in the snow vole (Chionomys nivalis). Allelic polymorphism across all loci and 28 individuals representing a single population in the Swiss Alps was high (mean = 10.1 alleles). No significant linkage disequilibrium between pairs of loci and no departure from Hardy,Weinberg equilibrium were found. These loci will be useful for describing mating systems and population structure and to investigate the genetic consequences of a species living in a highly fragmented habitat. [source] A review of the historical evidence of the habitat of the Pine Marten in CumbriaMAMMAL REVIEW, Issue 1 2001J. A. Webster ABSTRACT Place names and evidence from the literature show the Pine Marten (Martes martes) to have been well distributed in Cumbria until late in the nineteenth century, with a core area in the central fells. The habitat available to these martens is assessed and the species' status and the reasons for its decline reviewed. Despite the modern emphasis on the absolute importance of woodland to the Pine Marten, it is argued that historical Cumbrian populations survived successfully for many generations in highly fragmented habitats. [source] Population genetic structure of male black grouse (Tetrao tetrix L.) in fragmented vs. continuous landscapesMOLECULAR ECOLOGY, Issue 9 2003Alain Caizergues Abstract We investigated the association of habitat fragmentation with genetic structure of male black grouse Tetrao tetrix. Using 14 microsatellites, we compared the genetic differentiation of males among nine localities in continuous lowland habitats in Finland to the genetic differentiation among 14 localities in fragmented habitats in the Alps (France, Switzerland and Italy). In both areas, we found significant genetic differentiation. However, the average differentiation, measured as ,, was more than three times higher in the Alps than in Finland. The greater differentiation found in the Alps is probably due to the presence of mountain ridges rising above natural habitats of the species, which form barriers to gene flow, and to a higher influence of genetic drift resulting from lower effective sizes in highly fragmented habitats. The detection of isolation by distance in the Alps suggests that gene flow among populations does occur. The genetic variability measured as gene diversity HE and allelic richness A was lower in the Alps than in Finland. This could result from the higher fragmentation and/or from the fact that populations in the Alps are isolated from the main species range and have a lower effective size than in Finland. This study suggests that habitat fragmentation can affect genetic structure of avian species with relatively high dispersal propensities. [source] Fine-Scale Spatial Genetic Structure of the Distylous Primula veris in Fragmented HabitatsPLANT BIOLOGY, Issue 3 2007F. van Rossum Abstract: In Flanders (northern Belgium), the distylous self-incompatible perennial herb Primula veris is common, but mainly occurs in fragmented habitats. Distyly, which favours disassortative mating, is characterized in P. veris by two genetically determined floral morph types (pin or thrum). Using 18 polymorphic loci, we investigated fine-scale spatial genetic structure (SGS) and spatial distribution of the morphs within four populations from two regions that differ in degree of habitat fragmentation. We studied the contributions made by sexual reproduction and clonal propagation and compared the SGS patterns between pin and thrum morph types. Clonal growth was very restricted to a few individuals and to short distances. One population showed a non-random spatial distribution of the morphs. Pin and thrum individuals differed in SGS patterns at a small scale, suggesting intrapin biparental inbreeding, also related to high plant densities. This may be explained by partial self-compatibility of the pin morph combined with restricted seed dispersal and pollinator behaviour. There is an indication of more pronounced SGS when populations occur in highly fragmented habitats. From our findings, we may hypothesize disruption of the gene flow processes if these large populations evolve into patchworks of small remnants, but also a possible risk for long-term population survival if higher intrapin biparental inbreeding leads to inbreeding depression. Our study emphasizes the need for investigating the interactions between the heterostylous breeding system, population demographic and genetic structure for understanding population dynamics in fragmented habitats and for developing sustainable conservation strategies. [source] | ||||||||||