April 20, 2024

NASA Scientists Map 10 Billion Individual Trees in Africa’s Drylands To Estimate Carbon Stored

In a NASA-led study, researchers mapped nearly 10 billion individual trees in semi-arid areas of Africa, such as the one revealed here. Credit: Courtesy of Martin Brandt, University of Copenhagen, Denmark
Utilizing commercial, high-resolution satellite images and synthetic intelligence, an international team including NASA scientists mapped practically 10 billion private trees in Africas drylands in order to assess the quantity of carbon kept outside of the continents thick tropical forests. The outcome is the first detailed price quote of tree carbon density in the Saharan, Sahel, and Sudanian zones of Africa. The group reported its findings on March 1 in the journal Nature, and the information are free and openly readily available.
The scientists found there are much more trees spread out across semi-arid areas of Africa than previously believed, but that they also save less carbon than some models have actually anticipated. In the new research study, the team estimated roughly 0.84 petagrams of carbon are locked up in African drylands; a petagram is 1 billion metric loads.
Having a precise tree carbon price quote is necessary for environment change projections, which are affected by how long trees and other vegetation shop carbon. This “carbon residence time,” as scientists call it, is very brief for bushes and grasses, which grow seasonally, however much longer for trees that grow for many years. Understanding how much carbon a landscape stores depends on knowing exactly what is growing there.

Specific trees determined in satellite imagery, color mapped by the amount of carbon they consist of. Deep purple suggests lower carbon levels; yellow-white suggests greater levels. Credit: NASAs Scientific Visualization Studio
Beyond the huge tropical forests spread out throughout the middle of the continent, African landscapes vary from dry grasslands with a couple of trees to savannahs with spread trees to more damp locations with many scattered trees. This dispersed tree cover has actually made it difficult for scientists working to approximate the variety of trees in these areas, and there have actually frequently been over- or underestimates. Yet such measurements are vital for conservation efforts and for understanding the carbon cycle on our world.
” Our team collected and examined carbon data to the individual tree level across the large semi-arid regions of Africa or somewhere else– something that had actually formerly been done just on little, regional scales,” said Compton Tucker, lead researcher on the job and an Earth scientist at NASAs Goddard Space Flight Center in Greenbelt, Maryland. Previous satellite-based price quotes of tree carbon in Africas drylands often mistook grasses and shrubs for trees. “That resulted in over-predictions of the carbon there.”
Researchers mapped the sporadic tree cover in semi-arid Africa in order to much better calculate how much carbon is being kept. Credit: NASAs Goddard Space Flight
Carbon is continuously cycling in between the land, the environment, the ocean, and back. Trees get rid of carbon dioxide– a greenhouse gas– from Earths environment during the process of photosynthesis and shop it in their roots, trunks, branches, and leaves. For this reason, increasing tree cover is often suggested as a way to offset ever-increasing carbon emissions.
In the brand-new study, the team used sophisticated maker learning and expert system algorithms to sort through more than 326,000 industrial satellite images from the QuickBird-2, GeoEye-1, WorldView-2, and WorldView-3 satellites (operated by Maxar Technologies). The researchers acquired the images through NASAs Center for Climate Simulation and leveraged its Explore/ADAPT Science Cloud to organize and prepare the images for machine learning processing.
Researchers determined the circumference of trees and took other measurements to assist relate tree crown area in the satellite images to how much carbon is kept. Credit: Martin Brandt, University of Copenhagen, Denmark
Martin Brandt of the University of Copenhagen assembled AI training data from 89,000 private trees. Colleague Ankit Kariyaa, also at Copenhagen, adjusted a neural network so that computer systems might detect the individual trees in high-resolution 50-centimeter scale images of Africas drier, less verdant landscapes.
The researchers specified a “tree” as anything with a green, leafy crown and a nearby shadow. From this, they trained the artificial intelligence software to count the trees during millions of hours of supercomputing on heaven Waters supercomputer at the University of Illinois. When the team compared their machine-learning results with human assessments of the landscape, the computers were 96.5% proper in determining tree-crown location.
Field researchers determine the area of tree crowns and the associated masses of roots, leaves, and roots, of every tree in the allometry used to figure out how much carbon is stored within different parts of the tree. The tiresome work is essential to convert tree crown area into carbon quotes of trees. Credit: Martin Brandt, University of Copenhagen, Denmark
From measurements of tree crown area, the researchers can obtain the amount of carbon in each trees leaves, roots, and wood using allometry– the research study of how the attributes of living animals alter with size. A group led by Pierre Hiernaux of the University of Toulouse analyzed 30 various types of trees to determine leaf mass, wood mass, and root mass. They evaluated those masses of carbon and developed an analytical relationship to tree crown location.
The African tree carbon information are publicly available with a viewer app developed by the group. It permits individuals to view every tree in the study area and the quantity of carbon it shops.
These data could be helpful for trainees and researchers studying the carbon cycle, policymakers attempting to improve conservation efforts, and farmers who wish to determine the carbon kept in their farm.
Recommendation: “Sub-continental-scale carbon stocks of individual trees in African drylands” by Compton Tucker, Martin Brandt, Pierre Hiernaux, Ankit Kariryaa, Kjeld Rasmussen, Jennifer Small, Christian Igel, Florian Reiner, Katherine Melocik, Jesse Meyer, Scott Sinno, Eric Romero, Erin Glennie, Yasmin Fitts, August Morin, Jorge Pinzon, Devin McClain, Paul Morin, Claire Porter, Shane Loeffler, Laurent Kergoat, Bil-Assanou Issoufou, Patrice Savadogo, Jean-Pierre Wigneron, Benjamin Poulter, Philippe Ciais, Robert Kaufmann, Ranga Myneni, Sassan Saatchi and Rasmus Fensholt, 1 March 2023, Nature.DOI: 10.1038/ s41586-022-05653-6.

Having a precise tree carbon quote is necessary for climate change projections, which are influenced by how long trees and other plants store carbon. Beyond the huge tropical forests spread throughout the middle of the continent, African landscapes range from dry meadows with a couple of trees to savannahs with spread trees to more humid locations with lots of scattered trees. Previous satellite-based price quotes of tree carbon in Africas drylands frequently mistook yards and shrubs for trees. Field researchers determine the location of tree crowns and the associated masses of roots, leaves, and roots, of every tree in the allometry used to determine how much carbon is stored within different parts of the tree. From measurements of tree crown area, the researchers can obtain the quantity of carbon in each trees leaves, roots, and wood utilizing allometry– the study of how the attributes of living creatures alter with size.