They integrated field data with satellite imagery and high-resolution airborne Light Detection and Ranging (LiDAR) data to map the vegetation and to quantify carbon stocks throughout the Republic of Panama.
This is the first high-resolution national carbon map. The highest carbon stocks in Panama are in the humid forests on the Caribbean side (red). The lowest carbon stocks are in developed areas (blue).
Credit: Image courtesy Carnegie Airborne Observatory
The results are the first maps that report carbon stocks locally in areas as small as a hectare (2.5 acres) and yet cover millions of hectares in a short time. The system has the lowest demonstrated uncertainty of any carbon-counting approach yet—a carbon estimation uncertainty of about 10% in each hectare overflown with LiDAR as compared to field-based estimates. Importantly, it can be used across a wide range of vegetation types worldwide.
The new system, described in Carbon Balance and Management, will greatly boost conservation and efforts to mitigate climate change through carbon sequestration. It will also inform our understanding of how carbon storage can be used to assess other fundamental ecosystem characteristics such as hydrology, habitat quality, and biodiversity. The approach provides much-needed technical support for carbon-based economic activities such as the United Nations Reducing Emissions from Deforestation and Forest Degradation (REDD) program* in developing countries.
Panama has complex landscapes, with variable topography, and diverse ecosystems (ranging from grasslands and mangroves to shrublands and dense forests). As a result, Panama is an ideal laboratory to develop and test a method for quantifying aboveground carbon.
Lead author Greg Asner commented: "Three things make this national-scale study unique. First, Panama is an outstanding place for testing carbon mapping approaches due in part to the long-term forest studies that have been undertaken by our partners at the Smithsonian Tropical Research Institute (STRI). Second, we have applied the very latest techniques using high-performance instrumentation, resulting in demonstrably high accuracy at fine spatial resolution. And third the partnership permitted us to estimate our errors in a novel way, and we did so over every point on Panamanian soil."
In addition to Carnegie and STRI researchers, scientists from McGill University and UC-Berkeley combined measurement methods—an extensive and essential network of ground-based plot sampling, satellite imagery, and LiDAR measurements from the Carnegie Airborne Observatory—to achieve the unprecedented accuracy.
LiDAR uses reflected laser light to image vegetation canopy structure in 3-D. The scientists calibrated the LiDAR measurements, taken at one-meter resolution throughout nearly one million acres (390,000 hectares), to the carbon density in 228 regional field plots, established and sampled by the collaborating scientists. They used 91 other plots to validate the LiDAR's aboveground carbon density estimates.
"Rarely has such a large number of field plots been available to validate LiDAR calibration independently," remarked Asner. "Our collaboration with STRI and its partners was vital to assess the accuracy of what we achieved from the air."
Traditional carbon monitoring has relied upon on-the-ground sampling of field plots, but this approach usually represents just small areas of land and is time-consuming. "There has been growing interest in using satellite imagery to cover larger areas, but it is low resolution both spatially and in terms of the structural information about the vegetation," described Carnegie author Joseph Mascaro. "In some parts of Panama, different global methods disagree by more than 100% at square-kilometer scale."
That's where the airborne LiDAR comes in. It directly probes the ecosystem's physical structure, which Carnegie scientists have repeatedly proven to be tightly linked to tropical carbon stocks. These measurements are the bedrock for mapping and estimating the amount of carbon locked up in plants from dense forests to shrublands.
The researchers then were able to scale up the plot and LiDAR data with freely available satellite data on topography, rainfall and vegetation to model carbon stocks at the national level.
The LiDAR and satellite combination were able to account for variations in the carbon pattern from differences in elevation, slope, climate, and fractional canopy cover over the entire country. For instance, the scientists found that highest carbon levels are in humid forests on the Caribbean side of Panama, often exceeding 110 tons of carbon per hectare (2.5 acres). In contrast, large regions were deforested to very low carbon levels, such as in the developed regions outside the protected watershed of the Panama Canal. Human activity is the overwhelming driver of carbon stock patterns in Panama.
"Panama is one of the first UN REDD partner countries, and these new maps put the country at the forefront of high-resolution ecosystem management." said co-author and STRI's director Eldredge Bermingham, "The new carbon mapping approach could be the model for other tropical nations."
*The objective of UN-REDD+ is to create a financial incentive for developing countries to protect their forest resources in order to offset increasing carbon emissions. By creating financial value for the carbon stored in trees, the aim is to make forests more valuable standing than they would be harvested or destroyed.
The Carnegie Airborne Observatory is made possible by the Gordon and Betty Moore Foundation, the Andrew Mellon Foundation, the Grantham Foundation for the Protection of the Environment, Avatar Alliance Foundation, W. M. Keck Foundation, the Margaret A. Cargill Foundation, Mary Anne Nyburg Baker and G. Leonard Baker Jr., and William R. Hearst III.
The Department of Global Ecology was established in 2002 to help build the scientific foundations for a sustainable future. The department is located on the campus of Stanford University, but is an independent research organization funded by the Carnegie Institution. Its scientists conduct basic research on a wide range of large-scale environmental issues, including climate change, ocean acidification, biological invasions, and changes in biodiversity.
The research reported in this article was based on funding to the CAO described above, a Grantham Foundation for the Protection of the Environment grant to STRI, in addition to Grantham funding for the CAO, SIGEO/ForestGEO funds from the Smithsonian Institution and STRI, and support to the CAO Panama project from William R. Hearst III.
The Carnegie Institution for Science (carnegieScience.edu) has been a pioneering force in basic scientific research since 1902. It is a private, nonprofit organization with six research departments throughout the U.S. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.
The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is a unit of the Smithsonian Institution. The institute furthers the understanding of tropical nature and its importance to human welfare, trains students to conduct research in the tropics, and promotes conservation by increasing public awareness of the beauty and importance of tropical ecosystems. See http://www.stri.si.edu
Image of Panama's carbon map http://carnegiescience.edu/panamas_carbon_map
Watch the Carnegie Airborne Observatory make the world's highest resolution carbon map of a country (Panama) in less than one minute http://www.youtube.com/watch?v=_fQwv4coRR8
For copies of the paper contact the author
Greg Asner | EurekAlert!
Safeguarding sustainability through forest certification mapping
27.06.2017 | International Institute for Applied Systems Analysis (IIASA)
Dune ecosystem modelling
26.06.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.
For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...
What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.
To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...
The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....
A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...
Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision
Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...
19.07.2017 | Event News
12.07.2017 | Event News
12.07.2017 | Event News
20.07.2017 | Information Technology
20.07.2017 | Materials Sciences
20.07.2017 | Physics and Astronomy