|Panama has first high-fidelity nationwide carbon map
A team of scientists piloted a gadget-laden plane over every terrestrial ecosystem in Panama, firing 400,000 light pulses per second at the landscape with airborne Light Detection and Ranging (LiDAR) technology. Countless terabytes of crunched data later, researchers unveiled the most high-fidelity carbon map of any nation to date. Their work injects new levels of confidence into carbon stocktaking and the findings have the potential to revolutionize nation-level carbon trading.
"If the world is serious about counting its carbon resources in the long term, we need to do work like this," said the former director of the Smithsonian Tropical Research Institute (STRI) Eldredge Bermingham, a co-author of the study. "We need to establish standards."
The research shows just how important even a small country’s tropical forests are in the context of global greenhouse gas emissions. "According to our calculations, Panama’s forests hold more than 326 million metric tons of carbon," said Bermingham.
Lead author Greg Asner, from the Carnegie Airborne Observatory, says the Panama map breaks a low-resolution, high-uncertainty barrier that hinders confidence in traditional national carbon maps. "This is the first high-resolution carbon mapping of an entire country where each hectare of land has a carbon value and an uncertainty value," he says. The LiDAR-based estimates of aboveground carbon stocks had an uncertainty level of just 10 percent, relative to field-based estimates.
The high-tech mapping system is rooted in STRI’s track record of systematically gleaning fresh understanding from Panama’s highly diverse forests. It began decades ago by setting aside 50 hectares of old growth forest to ask simple questions about Panama’s hundreds of tree species. Today, the monitoring methodologies developed by STRI are applied to forest plots around the world. This standardized approach allows scientists to ask ever more complex questions about how climate change will alter forests and the ecosystem services they provide, including carbon capture.
In recent years, STRI scientists have refined the on-the-ground techniques and equations used to quantify carbon stocks. Standard procedures include measuring tree girth and height, and placing those and other variables - including each tree’s specific wood density - into formulas that estimate biomass. While these techniques are quite accurate at the plot level, scaling up to regional and national scales has been tricky.
Enter the Carnegie Airborne Observatory and its expertise with remote sensing technology like LiDAR. Using STRI’s plot carbon data to calibrate their Panama LiDAR scans, CAO produced the multicolored map of the Central American nation. It ranges from the deep blue of low-carbon dry deforested areas to the dark red of high-carbon rainforests.
"Panama is a beautiful model country because it has a wide range of ecosystems," said Asner, adding that Panama’s LiDAR map places the country at the vanguard of forest carbon mapping. "Smithsonian carbon science in Panama makes the country the ideal place to improve the calibration and validation of the LiDAR approach."