A study published in Nature Communications by researchers at the University of Maryland, Northern Arizona University, the University of Arizona and other institutions has found that worldwide protected forests have an additional 9.65 billion metric tons of carbon stored in their aboveground biomass compared to ecologically similar unprotected areas - a finding that quantifies how important protected areas are to continued climate mitigation efforts.
"This is one of the first demonstrations of how new remote sensing technologies can be used to obtain detailed biomass estimates"
The study, which was jointly funded by the U.S. National Science Foundation and NASA, used accurate forest height, structure and surface elevation data produced by NASA's Global Ecosystem Dynamics Investigation.
The researchers compared protected areas' efficacy in avoiding emissions to the atmosphere with unprotected areas' ability to do the same and tested the assumption that protected areas provide disproportionately more ecosystem services - including carbon storage and sequestration - than unprotected areas.
"We have never had these 3D satellite data sets before, so we have never been able to map forest carbon accurately at this scale," said Laura Duncanson, lead author of the study. "Analyzing the data to discover the magnitude of avoided emissions in protected areas shines yet another light on the global importance of forest conservation."
The biggest, most climate-positive impact the researchers observed came from the protected, moist broadleaf forest biome in the Brazilian Amazon, with Brazil contributing 36% to the global signal.
Another key finding was that the amount of aboveground biomass - the dry mass of woody matter in vegetation that stands above the ground - gained from protected areas is roughly equivalent to one year of annual global emissions from fossil fuels.
Previous attempts to quantify protected areas' biomass content had high uncertainties and biases, as past satellite biomass products are known to saturate in high biomass forests, such as old-growth protected areas.
"This is one of the first demonstrations of how new remote sensing technologies can be used to obtain detailed biomass estimates," said Kendra McLaughlan, a program director in NSF's Division of Environmental Biology. "This study signals a new era in tropical forest ecosystem science."
