Kenya launched a US$400 million appeal with the UN Environment Programme (UNEP) on Wednesday to save the Mau Forests Complex, the country's biggest closed-canopy forest and a vital water catchment area.

Experts say the Mau Complex has lost some 107,000 hectares - or about a quarter - of its trees over the last two decades due to illegal settlement, logging and charcoal burning encouraged by corrupt officials.

That threatens to affect energy generation, tourism, agriculture and water supplies to cities and industry, doing severe damage to east Africa's biggest economy.

"We gather here to define the way forward for the Mau," Prime Minister Raila Odinga said at UNEP headquarters.

"I wish to appeal to every Kenyan and development partner to support the government's efforts ... by ensuring adequate resources are mobilized to preserve and conserve the ecosystem."

The money would be used to restore and replant degraded areas, create a strategic management plan, raise public awareness and carry out boundary surveys, a UNEP statement said.

The Mau was broken into 22 blocks by human settlement over the last century. But the real devastation began in 1997 when large plots were dished out by the government of former President Daniel arap Moi to win votes during an election.

Kenya's new coalition government set up a task force in July last year to reverse the destruction, which UNEP says could cost the tourism, tea and energy sectors alone at least $300 million.

But disputes over the land allocated in the forest have set Odinga against allies, including his former right-hand man and Agriculture Minister William Ruto.

Ruto's Kalenjin community was the main beneficiary of the hand-outs during Moi's era in the late 1990s. Odinga has insisted any land given out illegally should be returned.

Experts have warned that continued destruction of the Mau Forests Complex will lead to a water crisis that could extend far beyond Kenya's borders.

"We are looking at securing the livelihoods and economies of millions of Africans who directly and indirectly depend on the ecosystem," Odinga said.

Reuters