In situ and Ex situ Conservation of Commercial Tropical Trees - ITTO

140Two examples on conservation through increased utilisationAn example of a species that is well suited for an increased utilisation strategyis Prunus africana, a tree species native to the African highlands. Its bark isutilised to extract a medicament used for treatment of benign prostatichyperplasia. The bark is usually harvested by felling trees in natural stands, andthis has led to extreme overexploitation of the species. The species is listedunder CITES appendix II regulating trade with endangered species, and allinternational trade must therefore be under licence. World Conservation Centrehas listed the species as vulnerable at the species level. Genetic diversity withinthe species is certainly being strongly eroded.ICRAF has analysed options for conservation of the genetic resourcesof Prunus africana (see e.g. Dawson & Were 1999). They find that the speciesis fairly easy to cultivate on-farm and that the bark from the planted trees canbe extracted in a non-destructive way. Prunus africana offers the potential ofgenerating income for farmers cultivating the tree. The value of the globaltrade of Prunus africana is approximately 220 mill US$/year (Dawson & Were1999). At the same time, on-farm cultivation of this species will be an effectiveway to protect its genetic diversity, as well as to release the pressure on thefew remaining natural populations.Dalbergia cochinchinensis is one example of a valuable timberspecies found in the Indochina region (Soerianegara & Lemmens 1994) thathas – like other Dalbergia species - been subject to heavy logging. In Vietnam,Dalbergia cochinchinensis has been exposed to high rates of exploitation ofthe prime timber, and it is now considered a threatened species. In Thailand thepressure on the species has caused concern too. The species has been appointedtop priority by the FAO Panel of Experts on Forest Genetic Resources (FAO1999), and is classified as vulnerable by the World Conservation MonitoringCentre.For a long time, it has been a general assumption that Dalbergiacochinchinensis trees grow slowly when cultivated. Also, that the seed wasnot easy to handle. The species has therefore not been included in plantingprogrammes. However, a demonstration plot in Laos has shown that it cangrow quite fast if cultivated under suitable conditions (STRAP 1995). The woodis extremely valuable, and the value produced per ha far exceeds the valueproduced by the fast growing eucalypts or Acacia mangium. Planting Dalbergiacochinchinensis as alternative to the often-planted eucalypts can thus bothprovide superior income and protect the genetic resource of the species. Effortshave been made to support identification of - and seed collection from - goodseed sources to be used for plantings. Such plantings can serve as seed sourcesfor commercial seed procurement later on (LTSP 2000), and thus form the