Reproductive biology and population genetics of trees
My research focuses on the genetics of tree populations, human impacts (e.g. fragmentation, logging) on such populations and applications to issues of use and conservation in natural and agro-ecosystems. Recent research has focussed on the genetic effects of fragmentation on remnant stands and trees, which are currently under debate. Whilst fragmentation may reduce populations below critical size and gene flow to levels below that needed to prevent genetic drift, it may also increase or alter patterns of gene flow between remnant populations. Consequently, even in severely fragmented landscapes, remnant forest patches and trees may be effective and important in conserving genetic diversity.
With Tonya Lander and Stephen Harris we studied how land-uses vary in the degree to which they present a barrier to, or facilitate, gene flow, depending on the ecological requirements of the organism and the ecological attributes of the matrix. The study focused on an endangered endemic tree from Chile, Gomortega keule (queule; Gomortagaceae), using an ecologically explicit landscape. Our results have significant implications for; theoretical landscape ecology, how habitat corridors and biological reserves are designed, and landscapes maybe simultaneously managed for conservation, economic and social value. This was part of a Darwin Initiative project.
As part of the SEEDSOURCE project (with Paul Rymer, Christina Vinson) we used field and laboratory techniques to study the genetic resources of neotropical trees (partners in Brazil, Costa Rica, Ecuador, UK, France, Germany, Italy). The overall aim was to provide best practice for sourcing tree germplasm for use within degraded landscapes to ensure the use of best adapted material, that maximises production, without eroding genetic and ecosystem diversity and long term adaptive potential. Integration of climatic, topographic and substrate information with genetic differentiation and diversity estimates from non-coding and potentially coding genetic markers and adaptive performance from growth trials to produce appropriate translocation guidelines for 16 study species. Work at Oxford covered Cordia alliodora, Pachira quinata, and Swietenia humilis.
Application of research results
I am also interested in knowledge exchange through the development of appropriate materials. As part of the SEEDSOURCE project and in conjunction with Bioversity International (for whom I am an Honorary Research Fellow), I have developed a series of training modules for use in the teaching of forest genetic resources. Each module uses actual data and visual teacher resources to examine the relevance and use of genetic information in the formulation and implementation of conservation actions. With Jesus Cordero-Salvado and researchers at CATIE, we published the book Central American trees: source book for extension workers. This book was also the focus for a training programme on the production of extension materials throughout Central America.
