The reports from the U.S.-based Rights and Resources Initiative (RRI) said this massive potential leap in deforestation could add to global warming and put pressure on indigenous forest dwellers that could lead to conflict.

"Arguably we are on the verge of the last great global land grab," said Andy White, co-author of "Seeing People Through the Trees," one of the two reports.

"Unless steps are taken, traditional forest owners, and the forests themselves, will be the big losers. It will mean more deforestation, more conflict, more carbon emissions, more climate change and less prosperity for everyone."

RRI is a global coalition of environmental and conservation non-government organisations with a particular focus on forest protection and management and the rights of forest peoples.

White's report said that unless agricultural productivity rises sharply, new land equivalent in size to 12 Germanys will have to be cultivated for crops to meet food and biofuel demand by 2030.

Virtually all of it is likely to be in developing countries, principally land that is currently forested.

The second report, "From Exclusion to Ownership", noted that governments still claim ownership of most forests in developing countries, but said they had done little to ensure the rights and tenure of forest dwellers.

It said people whose main source of livelihood is the forests were usually the best custodians of the forests and their biodiversity.

RRI said governments were failing to prevent industrial incursions into indigenous lands. Its report noted that cultivation of soy and sugar cane for biofuels in Brazil is expected to require up to 128 million hectares of land by 2020, up from 28 million hectares now, with much of it likely to come from deforestation in the Amazon.

"We face a deficit of democracy plagued by violent conflict and human rights abuses," said Ghanaian civil rights lawyer Kyeretwie Opoku, commenting on the reports.

"We must address underlying inequalities by consulting and allowing forest peoples to make decisions the themselves regarding the actions of industry and conservation," he added.