By Mark Kinver
Science and environment reporter, BBC News
A multi-billion dollar deal tabled at the Copenhagen climate summit could lead to conflicts in forest-rich nations, a report has warned.
The study by the Rights and Resources Initiative said the funds could place "unprecedented pressure" on some areas.
Six nations offered $3.5bn as part of global plans to cut deforestation, which accounts for about 20% of all emissions from human activity.
Campaigners warn the scheme fails to consider the rights of forest people.
The money - tabled by Japan, Norway, Australia, France and the US and UK - was made available under the UN's Reducing Emissions from Deforestation and Degradation (Redd) scheme.
However, delegates in the Danish capital failed to reach agreement on the mechanisms needed to monitor and manage the framework.
"One of the things that the world has learned over the years is that Redd is far more difficult than many people imagined," said Andy White, co-ordinator of RRI, a US-based think-tank, and one of the report's lead authors.
"The forested areas of the world - by and large - have very high levels of poverty, low levels of respect for local rights, and a very low level of control among local people to shape and control their destiny.
"So the rather simplistic notion that money from the rich North can control or limit deforestation was unrealistic."
Redd was developed as a global concept that would provide developing countries with a financial incentive to preserve forests.
The Copenhagen conference was expected to finalise an international Redd finance mechanism for the post-2012 global climate change framework.
The RRI's report, The End of the Hitherlands, said that there would be "unparalleled" attention and investment in forests over the coming year.
It asked: "But who will drive the agenda and who will make the decisions?"
The authors said studies showed that there was the potential for "enormous profits", but this would lead to increased competition for forest resources between governments and investors on one hand, and local communities on the other.
Dr White told BBC News that the UN-Redd scheme still had "tremendous potential".
"It requires, from our perspective, that the governments who tabled the $3.5bn quickly get together and decide on the standards and mechanisms that they will set up," he suggested.
"This would send the necessary signals to the private sector, as well as forest-rich nations, about what is expected from them in order to comply with the policy.
"Sorting out the institution arrangements in developing nations in order to manage the forest market is a huge undertaking."
But the report said that the "unprecedented exposure and pressure" on forest regions was being met by a rise in local groups setting up co-operatives and representative bodies.
The authors added that it gave "nations and the world at large a tremendous opportunity to right historic wrongs, advance rural development and save forests".