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Talbotiella gentii : genetic variation and conservation. Species conservation strategies. David Boshier, Daniel Dompreh and Mike Swaine. MSD. Bandai Hills. Worobong. Yongwa. Sapawsu. ME. Krobo. D SD. SM. 100km. WE. Forest Reserves in Ghana and distribution of Talbotiella gentii
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Talbotiellagentii: genetic variation and conservation Species conservation strategies David Boshier, Daniel Dompreh and Mike Swaine
MSD Bandai Hills Worobong Yongwa Sapawsu ME Krobo D SD SM 100km WE Forest Reserves in Ghana and distribution of Talbotiella gentii Dompreh, 2008
Records of Talbotiella populations in Ghana Red dots = Extant populations, Yellow dots = Extinct populations.
Yogaga Bandai
Talbotiella gentii 15 of 28 populationsnow extinct Most of those extinctare outside reserves Threats inside and outside reserves from fires, firewood cutting Populations range in size from 2-500 adult trees
1982 Damage of Talbotiella population at Krobo mountain from fire and fuelwood exploitation over 23 years 1990 2005
Preservation of actual diversity Conservation of evolutionary potential Mantain options for future generations, while satisfying present needs Conservation alternatives
How big is “big enough”? • 50/500 rule (Franklin 1980) • 50 - inbreeding depression to acceptable level • 500 - sufficient for new variation from mutation to replace that lost by genetic drift • effective population size (Ne) more critical than survey numbers (N) - may need 5,000! • in trees Ne smaller than N due to: overlapping generations, dioecy, asynchronous flowering, fecundity differences between individuals
Where should we conserve? In situEx situ In situ- reserve system of undisturbed, protected areas within natural distribution (ecosystem based) Ex situ- artificial maintenance of populations outside natural distribution (species based)
Conservation of biodiversity in situ : trees as a paradigm • Ideal reserve model • Emphasis: large, continuous, protected areas • Limitations: location, size, security, biology: • movement of animals • extensive distribution of many species • gene flow between populations • upland, non agricultural areas essential but not sufficient
Conservation of biodiversity ex situ : methods and limitations Seed banks - problems of regeneration Plantations - changes in gene frequencies, few populations Botanical gardens - deficiencies for gene pool conservation
Conservation of biodiversity ex situ : methods and limitations • Useful, but resources limit application to few species (usually commercial) • Last possibility holding for highly endangered species • Complementary to other approaches
Table 3 Within population genetic variability in Talbotiella gentii, estimated by percentage of polymorphic loci for 83 RAPDs polymorphic bands (8 primers)
Figure 3. Effect of geographic distance of pollen source on initial fruit set in Talbotiella gentii
Talbotiella gentiieach group summarize on wall chart paper or PowerPoint Remember - need a conservation objective - prioritize actions – resources are limited list problemsby type - genetic, which pops. too small? which are different? - other types of problems whichconservation methods - in situ, ex situ, circa situm? who? will do, what? where? how will you pay for it?