3D mapping reveals climate impact of selective logging

3D mapping reveals climate impact of selective logging


Peru: Scientists, using a combination of satellite imagery, airborne-laser technology and ground-based plot surveys to create three-dimensional high resolution carbon maps of the Amazon rainforest, have documented a surge in emissions from deforestation and selective logging following the paving of the Trans-Oceanic Highway in Peru.

The study, published in the early edition of the Proceedings of the National Academy of Sciences, reveals that selective logging and other forms of forest degradation in Peru account for nearly a third of emissions compared to deforestation alone. The findings, which demonstrate the feasibility of using LiDAR and satellite imagery over large areas of tropical forest, have important implications for monitoring, reporting, and verifying emissions reductions under proposed Reduced Emissions from Deforestation and Degradation (REDD) programmes, which could compensate developing countries for protecting and sustainability managing their forests.

“We’ve demonstrated that a cost-effective use of airborne LiDAR and free satellite data can speed up the process of carbon mapping and greatly reduce uncertainties in tracking carbon emissions from land-use change in the humid tropics,” said the lead author, Greg Asner, a researcher at the Carnegie Institution’s Department of Global Ecology at Stanford University.

Asner and colleagues used a four-step process to map emissions over 4.3 million ha of the Peruvian Amazon. The vegetation types and disturbance were measured by satellite; the 3-D vegetation structure was mapped using the LiDAR system (light detection and ranging) aboard the Carnegie Airborne Observatory, a small airplane; the data was ground-truthed using field plots on the ground; and the satellite and LiDAR data was integrated to create “high resolution maps of stored and emitted carbon,” according to a statement from the Carnegie Institution.

Source: Mongabay