Green group Conservation International said last month that Equatorial Guinea had pledged itself to this goal, but this was the first official confirmation from the government.

The mainland of the small, oil-rich nation is home to a variety of rare species including gorillas and giant frogs.

"Before oil was discovered we had to cut our trees because there was no other alternative," said Ofa Mbo.

Equatorial Guinea's government is often criticised by activists for graft and repression, so it remains to be seen if its ecological commitment will translate into reality on the ground. But it is sparsely populated and has growing oil revenues so it has the capacity to take action.

Liberian President Ellen Johnson-Sirleaf said in a pre-recorded video address that her country planned a US$30 million fund to protect its rainforests which still covered 50 percent of its territory despite a civil war in which timber revenues were used to buy guns.

"Liberia has successfully emerged from 14 years of civil conflict. In the future we may be able to develop a vibrant ecotourism industry," she said.

The five-day Antananarivo conference will focus on ways to use Africa's ecological treasures to help poverty relief while also protecting them.

Topics will include how to value ecosystems and the services they render, the use of debt relief for conservation, and the links between the environment, poverty and health.

Madagascar was chosen as the host because of its unique wildlife and the government's commitment to conservation in one of the poorest countries in the world.