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dc.contributor.authorMortimer, Elizabeth
dc.contributor.authorMcGeoch, Melodie A.
dc.contributor.authorDaniels, Savel R.
dc.contributor.authorJansen van Vuuren, Bettine
dc.date.accessioned2008-04-08T03:56:08Z
dc.date.available2008-04-08T03:56:08Z
dc.date.issued2008
dc.identifier.issn0954-1020en
dc.identifier.urihttp://hdl.handle.net/123456789/337
dc.description.abstractSeven community complexes have been described across sub-Antarctic Marion Island, amongst these fellfield that comprise low plant cover dominated by Azorella selago Hook. f. Azorella is considered a keystone species since it forms nutrient rich environments for microarthropod communities and epiphytic plants. Two distinct growth forms typify Azorella, namely discrete cushions and continuous mats. Whether these continuous mats normally consist of a single large cushion individual, or whether several individual plants merge, interdigitating to form a continuous area, remains unclear. As such, it is important to obtain some measure of Azorella growth dynamics before embarking on phylogeographic studies. Previous genetic studies indicated that several of these microarthropod species are significantly substructured across Marion Island, but it remains unclear whether similar subdivisions characterize Azorella. We used chloroplast sequence data (trnH-psbA) and amplified fragment length polymorphism (AFLP) to investigate these questions. No sequence variation characterized the trnH-psbA region in Azorella across Marion Island. In contrast, the AFLP results indicated that an A. selago mat comprises multiple individuals. We argue that mats can be formed through at least two processes namely fragmentation, where parts of the cushion plant die off creating open areas for the establishment of different individuals and/or to a high density of interdigitating individuals merging to form the mat. Fragment data further indicated significant substructure for Azorella across Marion Island (FST=0.101, P=0.01) and we attribute this to past vicariance.en
dc.format.extent328299 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoenen
dc.publisherCambridge Journalsen
dc.subjectamplified fragment length polymorphism (AFLP)en
dc.subjectFragmentationen
dc.subjectcushion planten
dc.subjectgenetic similarityen
dc.subjectPrince Edward Islandsen
dc.titleGrowth form and population genetic structure of Azorella selago on sub-Antarctic Marion Islanden
dc.typeJournal Articlesen
dc.cibjournalAntarctic Scienceen
dc.cibprojectNAen


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