Two twice ‘extinct’ trees rediscovered in coastal Tanzania

Posted on March, 12 2012

Scientists have confirmed the rediscovery of two tree species that were feared to have become extinct twice, according to a report published in the Journal of East African Natural History. The finds were made in highly threatened fragments of dry forest in coastal Tanzania.
Scientists have confirmed the rediscovery of two tree species that were feared to have become extinct twice, according to a report published in the Journal of East African Natural History. The finds were made in highly threatened fragments of dry forest in coastal Tanzania.

One of the trees, Erythrina schliebenii, belongs to the genus of ‘coral trees’ which have spectacular red flowers and viciously spiny trunks. The tree was only known from two collections from the 1930s until it was recollected in a small patch of unprotected forest in 2001. It was feared that it might have gone extinct again when a Dutch company cleared part of that forest for a biofuel plantation in 2008.

The other tree, Karomia gigas, was only known from a single specimen cut down a few years after it was first discovered in coastal Kenya in 1977. Another tree was found some 600 km away in a tiny fragment of forest in Tanzania in 1993, but a more recent search at the same site was unable to relocate it.

Last year botanists from the University of Dar es Salaam set out to look for both trees near where they had been found. They discovered small populations of both in remote coastal forest near Kilwa in southeast Tanzania.

The coral tree Erythrina schliebenii was collected with mature seeds for the first time, allowing taxonomists at the Royal Botanic Gardens in Kew to confirm it as a distinct species. This was only possible through consulting reference collections of coral tree specimens housed in herbaria throughout the world.

Neil Burgess, senior advisor to WWF’s conservation and Africa programme, said: "The re-discovery of these two trees highlights the lack of information in a forested region where we could be losing species without ever knowing they are there.

“Conservation of these forests, in partnership with local villages, is essential. This can also lead to standing forest being used as an income source for communities through the development of sustainable logging initiatives.”

Recent infrastructure development, together with a rapid population increase, are putting the coastal forests of southeast Tanzania under increasing threat of being degraded and cleared.

Erythrina schliebenii has only survived because it grows in rocky areas that are not usually cleared for cultivation, but even those areas will be cleared one day if nothing is done,” added botanist Cosmas Mligo from the University of Dar es Salaam.

Roy Gereau from the Missouri Botanical Garden, who coordinates the IUCN Red Data book listing of East African plants, said: “Both trees are still in critical danger of extinction, given that fewer than 50 individuals of each species are known.”

Notes to Editors:
About WWF WWF is one of the world's largest and most respected independent conservation organizations, with more than 5 million supporters and a global network active in over 100 countries. WWF's mission is to stop the degradation of the earth's natural environment and to build a future in which humans live in harmony with nature by conserving the world's biological diversity, ensuring that the use of renewable natural resources is sustainable, and promoting the reduction of pollution and wasteful consumption.

Recent fieldwork in Tanzania’s Coastal Forests was supported by the Global Environment Facility through the United Nations Development Programme, WWF and the Tanzania Forest Service. Their work forms a part of the WWF’s ‘Coastal East Africa’ Global Initiative and the UNDP GEF project ‘expanding the protected area subsystem in the coastal forests of Tanzania’.

Further details are available online from the latest issue of the Journal of East African Natural History, available online at http://www.bioone.org/loi/eanh

Paper citation: Clarke, G.P., N.D. Burgess, F.M. Mbago, C. Mligo, B. Mackinder & R.E. Gereau (2011). Two ‘extinct’ trees rediscovered near Kilwa, Tanzania. J. East African Nat. Hist. 100(1&2):133–140.

For further information, please contact:
Robin Clegg, Tel: +44 7771 818707, email: rclegg@wwf.org.uk


Erythrina flowers
© Frank Mbago
Cosmas Mligo with the fruit and a leaf of Karomia gigas
© Cosmas Mligo