
Tropical forests are complex ecosystems, and their management often involves the sustainable exploitation of a range of resources, including non-timber products. Genetic diversity represents an essential component promoting population level adaptation ensuring the continued proliferation of individual species within tropical systems. Reduced genetic diversity can lead to loss of adaptive variation and inbreeding depression, both of which can threaten the long-term survival of isolated populations. Many tropical species are currently extracted at unsustainable levels or their habitats are being degraded, threatening the long-term survival of species within this ecosystem. Whether harvested from natural or managed landscapes, there is a need to develop a practical, operational system concerned with the management of genetic sustainability .
In this project, a programme of research aimed at measuring key genetic indicators of sustainability in tropical forest
ecosystems will be undertaken. The aim is to evaluate the level and dynamics of genetic diversity in natural forest populations. The sustainability of current management practices will be assessed in selected extracted species using computer simulation of field genetic data. Specific sustainable extraction/management strategies arising from this process will be promoted to forestry stake holders, who will be made more aware of the genetic implications of management. To aid this process it is necessary to establish criteria and indicators. An important criterion already identified for genetic diversity is conservation of the processes that maintain genetic variation (Namkoong et al., 1996), for which four indicators have been identified:
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Levels of genetic variation
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Mating system processes
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Directional change in gene or genotype frequencies
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Gene migration between populations.
However there are three additional issues that need to be considered for genetic diversity in tropical
ecosystems:
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The formulation of genetic criteria and indicators depend on understanding of the processes we are proposing to
research
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These criteria and indicators are many, complex and interacting, and that therefore a modelling approach is
appropriate
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There are still many knowledge gaps that need to be filled before a model produces realistic information, these can be examined further through integrated field and laboratory
work
GENEO-TROPECO therefore has the following objectives: