Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.653345
Title: Conservation genetics of New Caledonian Araucaria
Author: Kettle, Christopher
Awarding Body: University of Edinburgh
Current Institution: University of Edinburgh
Date of Award: 2005
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Abstract:
The Araucaria conifers of New Caledonia are a globally significant group with 13 endemic species, eleven of which are threatened with extinction. The critically endangered conifer Araucaria nemorosa and common widespread congener A. columnaris, provide a comparative framework in which to empirically investigate the genetic consequences of fragmentation in understudied anemophilous group. A survey of the genetic diversity at nuclear microsatellite loci over the species’ total range suggests that adults of A. nemorosa are not genetically depauperate, maintaining equivalent levels of genetic diversity to A. columnaris (Ae=20.66; 14.7; He=0.715; 0.654 in A. nemorosa and A. columnaris respectively). However, quantifying genetic diversity and inbreeding coefficients in seedling populations revealed a significant loss of allelic richness and a two-fold increase in the inbreeding coefficients in A. nemorosa  seedlings compared to adult populations (FIS 0.195 vs 0.096). This indicates that genetic bottlenecks and elevated inbreeding are likely consequences of fragmentation in A. nemorosa populations. Stand structure, reproductive characteristics and population genetic structure within remnant populations of A. nemorosa were assessed in order to place the genetic consequences of fragmentation in an ecological context. This indicates that in severely fragmented populations ecological and genetic factors can interact to determine population persistence. The reproductive characteristics of A. nemorosa were evaluated, which revealed that seed set is generally very low (5% seed set per cone) with a high variance among individuals. The consequences of fertility variance for the effective population size were explored using both ecological and genetic methods. This suggests that fertility variance will have few consequences for population genetics of wild seedling cohorts. However, in a single season, the number of adults contributing to the seed crop may be small and this has implications for the sampling of germplasm for forest restoration.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.653345  DOI: Not available
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