Science - September 29, 2005

Healing plants in Benin becoming extinct

There are far more plant species in the forests of Benin that are threatened by extinction than was previously assumed. These include valuable medicinal plants that are used to treat malaria and psychiatric complaints. In his PhD thesis, Dr Aristide Adomou recommends that the forests be protected to prevent the plants becoming extinct.

Adomou made an inventory of the vegetation in the whole of Benin, from which he compiled a Red List of 280 threatened species. Biologists had been using a list of just 48 plants, which was compiled in the 1970s. Researchers made other lists in the ensuing decades, but these are even shorter.

Adomou’s list of plants in danger is long and contains examples that will be sorely missed by biologists and the local population should they disappear from Benin. Adomou: ‘I would include Zanthoxylum zanthoxyloides, the roots of which are used to treat malaria and anaemia. The roots of the plant Rauvolfia vomitoria are used to treat psychoses and other psychiatric disorders.’

About twenty percent of Benin is still covered with forest, but these are making way for plantations, salt mines and human habitation at an alarming rate. From his inventory Adomou has distinguished a number of ecologically valuable vegetation types including mangroves, swamp forests and higher forest areas.

Adomou’s supervisor Professor Jos van der Maesen is impressed with Adomou’s nationwide inventory. ‘The remaining forests in Benin can only be protected if they are designated as protected areas. By knowing what threatened plant species are present and where they are found, the government has a good basis for making policy. Adomou’s PhD thesis is an excellent handbook for this. / HB

Aristide Adomou received his PhD on 21 September. He was supervised by Professor Jos van der Maesen, chair of Biosystematics.