US: Two new research papers show that an advanced laser-based system for forest monitoring is at least as accurate as traditional plot-based assessments when it comes to measuring carbon in tropical forests.
The first paper, published in Remote Sensing of Environment by researchers from the Department of Global Ecology at Carnegie Institution for Science and the Smithsonian Tropical Research Institute (STRI), compared plot data for Barro Colorado Island, Panama — the most intensively studied tract of tropical forest on Earth — with carbon data derived from overhead flights using the Carnegie Airborne Observatory’s (CAO) LiDAR system. It found that “LiDAR-based uncertainties of aboveground carbon stocks are indistinguishable from errors obtained when doing the most detailed plot-based estimates.”
The second paper, published in Oecologia by researchers from Carnegie, STRI, and other institutions, laid out a universal equation for determining forest carbon stock values from LiDAR data. The equation — based on sampling of forests in Panama, Peru, Madagascar, and Hawaii — is adjusted for a forest region based two variables: basal area and wood density information, allowing researchers to “radically decrease” the time needed to calibrate airborne LiDAR data.
The research has important implications for mapping global forest carbon stocks, according to Greg Asner, the Carnegie Institution scientist who leads CAO. He said, “This new approach opens doors for really accurately monitoring how much carbon is stored in tropical forests, which has been one of the key challenges in developing international strategies to mitigate climate change.”