Saving an Endangered Palm: The Case of Carpoxylon

(page 2)

The FSP survey identified the palm’s broad ecology and morphology, and made observations on flowering and fruiting habits, using these to attempt to identify variability. It found a marked difference in tree height between the Tanna population and those in the rest of the country, the Tanna trees reaching a higher maximum height. There was, however, very little if any other easily observed variability. It also found that the natural stands seemed to be regenerating moderately successfully with a ratio of 2:4:13 of adults:juveniles:seedlings. However, the stands were so scattered and the sizes so small that the long term viability of the population was not assured.

Because there were so few mature trees left, it was important to establish the genetic variability of the species in order to ensure that what still existed was entirely protected. The survey conclusion was that the palm was highly vulnerable and approaching extinction. FSP contracted the Australian Institute of Marine Sciences to complete a DNA analysis on samples collected. This confirmed the existence of only three genetic varieties of the palm. All three occurred on only one island, Tanna, while only one of them occurred on all the other islands. One variety was identified as originating from only one cultivated tree in a village on Tanna.

There are several issues that raise serious concerns about the future of the Carpoxylon palm in Vanuatu:

• The population survey found that the natural population totalling 26 adult fruiting trees existed in very small and widely scattered stands of adult trees. This restricts cross fertilisation and maintenance of a healthy population with a good stock of genetic variability;
• Little is yet known of the flowering, pollination and reproductive system of Carpoxylon, i.e. extent of cross fertilisation, what size cross-breeding population is needed for viability in the long term, etc.;
• While the rate of regeneration observed during the survey showed it to be moderately successful, this does not guarantee long term viability if the total size of the population is insufficient anyway;
• Since the individual populations do not appear from the DNA analysis to contain much variability, the species is vulnerable to drastic changes in environmental conditions.
• The forest areas in which the three DNA varieties exist on Tanna are being cleared for agriculture purposes. The natural stand on Futuna consists of only 5 adult fruiting trees in a forest area that is dwindling in size due to agriculture clearing. Only on Aneityum is the forest less threatened by clearing. However, the population there seems to be of only one genetic variety and therefore still vulnerable to extinction with drastic environmental changes.

Clearly the population studies both in the field and through the DNA analysis showed the urgent need for action to save the palm and to conserve what little variability is left. Traditionally, the approach would have been to find some international funding agency to finance the necessary activities for its protection. However, the Profitable Environmental Protection project, under which the Carpoxylon research was undertaken, had a clear mandate to develop profitable enterprise as a tool for conservation.

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