"We found that conservation lands successfully protect against deforestation and forest disturbance," Greg Asner of the Carnegie Institution of Washington, US, told environmentalresearchweb. "We also found that the indigenous lands are relatively well-protected from major deforestation and logging activities."

Peru has around 661,000 sq. km of tropical forest. In recent years, the country's government has established large natural protection areas, set up indigenous territories and introduced forest management legislation for some land.

The satellite analysis revealed that only 1–2% of the rainforest damage took place within protected natural areas, while indigenous territories contained 11% of the forest disturbances and 9% of the deforestation. "These results show clearly that these two forms of land-use allocation can provide effective protection against forest damage," say the researchers in their paper. Forest concessions also appeared to protect against clear-cutting.

The Carnegie Landsat Analysis System (CLAS) uses satellite images to uncover forest changes at a resolution of 30m x 30m. The system, which employs complex detection algorithms to analyse satellite images, was originally developed between 1997 and 2002 to monitor logging in the Brazilian Amazon.

"Probably the most significant thing about our Peru work is our demonstration that forest monitoring and assessment can work if the satellite data are made available," said Asner. "Our methods have worked well in Brazil, and now Peru. We could do this in just about any country now, as long as the satellite images are collected and provided to scientists."

For this study, Asner and colleagues from Instituto del Bien Común, Peru, Stanford University, US, and Boston University, US, improved the CLAS detection algorithm with optimized atmospheric and haze correction, water/cloud masking processes as well as adding an automated-deforestation detection module.

"Now CLAS includes a deforestation module to match the forest disturbance module that was originally invented for mapping logging," said Asner. "So, now our approach maps out both clear-cutting (deforestation) and logging, as well as other forest disturbances."

The researchers' figures for deforestation in the region agree with estimates by the UN Food and Agriculture Organization (FAO), but are lower than data reported by the Peruvian government.

The team also found that 86% of all forest damage was concentrated in two regions – around the logging centre and associated road network of Pucallpa, and along a corridor centred on the city of Puerto Maldonado and the Inter-Oceanic Highway. Lack of road access appeared to be limiting damage to forest in more remote areas.

While protected natural areas and indigenous territories were relatively well-protected, the team found that logging concessions (which are designed to derive income from the Peruvian timber resource) are "leaky operations".

"What I mean is that forests designated for timber extraction are surrounded by other non-concession forests that should, in principle, remain intact," said Asner. "That is not the case. There is forest damage occurring in areas adjacent to concession areas. This is a cause for concern."

Now the team is working with collaborators from Yale University, US, to study deforestation and forest disturbance trends in Borneo. "We know that a lot of damage has occurred there already, so our current effort is to provide a retrospective look at what happened, and to understand why," said Asner.

The researchers reported their work in Sciencexpress.