Habitat loss caused clonality, genetic diversity reduction and reproductive failure in Santalum album (Santalaceae), an endangered endemic species of Indonesia

摘要

An economic-important endangered species native to Eastern parts of Indonesia, sandalwood, has been categorized as threatened species due to significant degradation and habitat loss caused by heavy exploitation. As it possessed pollen limitation, low reproductive success and self-incompatibility mechanism, habitat loss is able to have important conservation consequences. Allozyme and embryology observation used in this study to determine the effect of habitat loss on sandalwood grown in two of Gunungkidul populations; one was well managed as ex situ conservation and another was heavily wild-harvested. Result indicated significant reduction on genetic variability in harvested population that may occur as result of clonality on fragmented or isolated habitat, in which the remnant mother trees reproduced asexually by root suckers thus each individual was identified as a unique single clone. A low genetic variability, in turn, resulted to inbreeding depression and sexual reproductive failure. Rare and missing alleles found in harvested population indicated that several alleles were no more inherited in the next generation. Embryology observation indicated a reproductive failure as there were little or no sexual reproduction occurred in the harvested population, probably due to inbreeding depression. Clonality, biodiversity reduction and sexual reproductive failure are the main problems should be unravelled on designing the conservation strategy of sandalwood. The genetic infusion and enhancement of population size is recommended.