Over the years, the uses of 3-D scanning technology continue to advance. As a non-invasive, non-destructive technology, industries from medical and environmental to mining and construction have benefitted from 3-D laser scanning.
Now, the technology that maps out surfaces to create three-dimensional models is being used to measure carbon emissions from forests.
Weighing Trees Through 3-D Laser Scanning
According to Diamond Land Surveying, a Utah-based company that utilizes 3-D laser scanning, the technology delivers an incredible amount of detail in a short period. With trees covering 766 million acres or 33 percent of the total U.S. land area, using the 3-D laser scanning method is an efficient way of mapping forests.
This is exactly what a team of researchers from the University of Virginia, Smithsonian Conservation Biology Institute, and the Smithsonian Tropical Research Institute did.
Rainforests play a huge part in stabilizing the world’s climate. They not only provide essential ecosystem services but also hold 45 percent of carbon on land and absorb a third of human carbon emissions.
According to the researchers, approximately half of a tree’s dry mass is carbon, so to accurately measure a tree is to estimate its carbon storage. However, the study authors said, “these allometric equations are known to have high errors and biases, particularly in carbon-rich forests, because they were calibrated with small and often biased samples of destructively harvested trees.”
Even without the errors of allometry, this method is difficult because the researchers would need to cut down trees to get their measurements. Obviously, doing so is counterproductive to the trees’ purpose.
This issue can be solved, though, through a new technology called terrestrial laser scanning. Terrestrial laser scanners reproduce a forest environment in 3-D, allowing the researchers to explore trees in detail. They used the 3-D models of trees to estimate tree volume and, with wood density, to measure tree weight.
Estimating Forest Carbon
According to the researchers, this study was conducted to improve the existing assessments of global forest carbon.
“We used this new method to ask two main questions: is current tree allometry accurate and, if not, how can we improve it with terrestrial laser scanning?” said study author Atticus E.L. Stovall from the University of Virginia.
Through the terrestrial laser scanning technology, the researchers found that trees actually contain 25 percent more carbon than previously believed. This suggests that deforestation may be emitting more carbon than previously understood.
“With this new method of measuring trees, we can easily collect thousands of samples, ultimately giving us the best possible allometry for accurate estimates of forest carbon.”
NASA’s Forest Structure Measurement
Apart from the practical uses of information about carbon content in forests, this study is also linked to NASA’s Global Ecosystem Dynamics Investigation (GEDI), according to the researchers. The GEDI will measure the Earth’s forests using billions of laser pulses from space.
By combining this study’s terrestrial laser scanning and GEDI’s measurement of forest structure from space, scientists will be able to create the most detailed and accurate map of global forest carbon.