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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 - PowerPoint PPT Presentation
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Species conservation strategies
Talbotiella gentii: genetic variation and conservation
David Boshier, Daniel Dompreh and Mike Swaine
100km
MSD
ME
WE
D SD
SM
Krobo
Worobong
Bandai Hills
Yongwa
Sapawsu
Forest Reserves in Ghana and distribution of Talbotiella gentii
Dompreh, 2008
Records of Talbotiella populations in GhanaRed dots = Extant populations, Yellow dots = Extinct populations.
Sapawsu
Yogaga
Bandai
Yongwa
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
1990
2005
Damage of Talbotiella population at Krobo mountain from fire and fuelwood exploitation over 23 years
Aburi Botanical Gardens
Conservation alternatives
• Preservation of actual diversity
• Conservation of evolutionary potential
• Mantain options for future generations, while satisfying present needs
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 situ - reserve system of undisturbed, protected areas within natural distribution (ecosystem based)
Ex situ - artificial maintenance of populations outside natural distribution (species based)
In situ Ex situ
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
• Useful, but resources limit application to few species (usually commercial)
• Last possibility holding for highly endangered species
• Complementary to other approaches
Conservation of biodiversity ex situ : methods and limitations
Bottleneck genetic drift
Table 3 Within population genetic variability in Talbotiella gentii, estimated by percentage of polymorphic loci for 83 RAPDs polymorphic bands (8 primers)Population Population size No. of samples % polymorphic loci
AbiriwapongBotriansaYongwaNayomDoorkperSapawsuHospitalChaletAjena KuwereKroboYogoga HotelBooboheneOseikromSenkyesoKwame Addo
>1002
>1003921
>502
>50>5016
>20112720623
162
1355828648552222
16.32.1
13.65.23.98.10.88.44.83.17.77.94.42.12.12.12.1
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 problems by type- genetic, which pops. too small? which are different?- other types of problems
which conservation methods - in situ, ex situ, circa situm?who? will do, what? where?how will you pay for it?