Sustainable management of Neo -Tropical Tree Genetic Resources: Combining molecular and modelling methods to understand the structure and dynamics of gene diversity. Final Scientific Report. February 2002 - January 2006

摘要

Original Objectives:ud•Examine the structure and dynamics of genetic variation for a range of economically and ecologically important Central and South American tree species within natural ecosystems and identify the main factors that are responsible for partitioning of variation within speciesud•Examine the impact of identified extraction methods/habitat degradation (i.e. fragmentation, logging, forest clearance and domestication) on selected economically important speciesud•Produce a model tailored to the individual study species that will integrate field observations and DNA-based technologies to provide realistic simulations of the impact of differing land-use strategies and extraction regimes on the genetic resource base of impacted speciesud•Improve capacity to execute sound natural forest management by improving awareness of genetic implications of natural forest management and implementation of a modelling approach to setting sustainability strategiesududResults and Milestones:udDevelopment of molecular techniquesudSeveral new microsatellite primers were developed in a range of species; DNA extraction methods for target species were optimised; AFLP protocols were optimised and applied across the range of target species. Practical measures to maximise comparability of AFLP datasets between labs were designed, and standardised scoring and analysis techniques developed for the analysis stages. Several aspects of the methodological development were published in peer-reviewed journals. ududIdentifying biological determinants of genetic diversityudFor a list of 50 target species collections and information on biological characteristics were prepared, following protocols from WP1. All target species were analysed using AFLPs and a meta-analysis conducted. Within the timescale of the project only preliminary analysis was possible but this indicated significant effects of pollination and seed dispersal mechanism on population differentiation and within-population genetic diversity respectively. Geographic distribution was not found to have any effect. ududEffect of human-mediated processes on genetic diversity udSubstantial case studies were carried out examining the effects of human-mediated processes on genetic diversity in Pinus oocarpa, Araucaria angustifolia, Swietenia macrophylla (Brazil and Belize), Vochysia ferruginea, Symphonia globulifera and Theobroma grandiflorum. Important outcomes of the case studies in general showed the impact of population modification on tree mating systems (and hence genetic diversity maintenance), the scale of real gene movement within tree populations, the significance of population densities for gene flow patterns and highlighted potential forest management strategies to mitigate the genetic diversity impacts of harvesting.ududSimulation modelling of population genetic dynamicsudThe model, ECO-GENE, was adapted for use with the genetic datasets derived from case studies. In particular, a new module was designed for the model allowing sensitivity analysis to be performed. Simulations using empirical data from studies of Symphonia globulifera and Swietenia macrophylla were conducted. These studies highlighted the necessity for preparation of site-specific plans, and the importance of population density and the interaction between demography and growth and gene dispersal capability for capture and maintenance of genetic diversity in populations.ududDesigning Management strategies to maximize diversityudBoth scientific and non-technical communications were achieved during the project lifetime. Amongst other individual peer-reviewed papers, special issues of the journals Heredity (Nature Publishing Group) and Silvae Genetica were produced. Further paper writing and publication is ongoing. Additional dissemination of project outputs was achieved through preparation of a board game for schools and colleges and a high-level public workshop for the biodiversity conservation sector (in San Jose, Costa Rica), including attendees from the government’s Biodiversity Conservation Commission as well as a range of other public and private bodies with interests in the field.ud