Bryological and Lichenological Section/ABLS
Pohjamo, Maria , Korpelainen, Helena , Kalinauskaite, Nijole .
Restricted gene flow in the clonal liverwort Trichocolea tomentella in fragmented landscapes.
We studied the genetic diversity, gene flow and population structure among 18 populations of the clonal bryophyte Trichocolea tomentella located in Finland, Lithuania, the UK and Canada using DNA fingerprinting methods. T. tomentella is a habitat-limited, unisexual hepatic, which occupies spring and mesic habitats in woodland. The relatively small populations are increasingly fragmented with a high risk for extinction for extrinsic reasons. The presence of relatively high levels of genetic diversity regardless of population size highlights the role of even small remnant populations as important sources of genetic diversity in T. tomentella. The long-term accumulation of genotypes and somatic mutations may explain the observed levels of diversity. Gene flow among populations seems to be infrequent indicating dispersal limitation also on the relatively small spatial scale. Colonization within populations is not affected by isolation by distance suggesting the occurrence of random short range dispersal of detached vegetative fragments. The population structure study confirmed low mortality of shoots indicating a long life span of the clones espacially in favourable conditions. Efficient ramet production by branching is likely to operate against interspecific competition. To conclude, T. tomentella appears to persist well in undisturbed habitats due to clonal regeneration, although restricted dispersal capacity is likely to prevent successful (re-)colonization in the potential habitat patches of recovering forest landscapes.
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1 - University of Helsinki, Department of Applied Biology, P.O. Box 27, Helsinki, FIN-00014, Finland
2 - University of Helsinki, Botanical Museum, P.O. Box 7, Helsinki, FIN-00014, Finland
Presentation Type: Oral Paper:Papers for Sections
Date: Monday, July 28th, 2008
Time: 9:00 AM