The Population Genetic Consequences of Gene Flow during Colonisation and Regeneration of Forest Trees
Davies, Samantha. 2006 The Population Genetic Consequences of Gene Flow during Colonisation and Regeneration of Forest Trees. Heriot-Watt University, School of Mathematical and Computer Sciences, PhD Thesis, 311pp.Before downloading, please read NORA policies.
This thesis investigates the population genetics of colonisation in the neotropical pioneer tree Vochysia ferruginea. A combined approach of empirical molecular analysis and simulation modelling was used to understand how gene flow during colonisation impacts genetic diversity. Samples of adult, seedling and seed from two sites in Costa Rica were analysed to estimate mating system parameters, genetic diversity and gene flow. Spatial modelling was used to investigate the effects of seed and pollen dispersal on the genetic dynamics of recolonisation and to assess potential forest management strategies. Genetic diversity was higher in primary than in secondary forest indicating that colonisation caused a loss of alleles. However, higher diversity was found in secondary forests trees and seeds than in seedlings suggesting that, with time, high levels of gene flow may counter initial diversity loss due to founder effects. Genetic diversity and spatial genetic structure of individuals contributing to founding populations had significant and population-specific effects. High population densities appeared to decrease gene flow from pollen, impacting fine-scale spatial genetic structure and levels of biparental inbreeding. Modelling gene flow during colonisation illustrated the importance of long distance seed dispersal and demonstrated how seed from trees in continuous forest with high pollen flow can provide genetically diverse material for regenerating abandoned land.
|Item Type:||Thesis (PhD)|
|Programmes:||CEH Programmes pre-2009 publications > Biodiversity|
|Additional Keywords:||Vochysia ferruginea, Costa Rica, regeneration, microsatellites, modelling, pioneer, tropical trees|
|NORA Subject Terms:||Ecology and Environment|
|Date made live:||20 Jul 2009 14:58|
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