USA – Tropical rain forests are treasure houses of biodiversity, but there has been no effective way to inventory and monitor their plant species over large areas. As a result, we have limited understanding of how climate change, clearing, invasive plants, and other threats are affecting these delicate ecosystems.
A major advance in improving this situation is in the works, however. Gregory Asner of the Carnegie Institution’s Department of Global Ecology was just awarded a $1.8 million grant from the John D. and Catherine T. MacArthur Foundation to create a database of plant chemical and remote sensing signatures for tropical forest species. This large ground-based “Spectranomics Project” will expand Carnegie’s unique aerial mapping and remote-sensing capabilities to inventory and track rain forest vegetation around the globe, and it will enhance the value of satellite observations over tropical forest regions.
Tested and proven in the rain forests of Hawaii, the Carnegie Airborne Observatory (CAO), designed and operated by Asner and Carnegie’s Department of Global Ecology, is uniquely positioned to undertake large-area ecological studies.
With its instrumentation, techniques, and algorithms, the CAO can map forest canopy chemistry over nearly 40,000 acres per day.
The system is highly portable, flown aboard a fixed-wing aircraft. The CAO uses a waveform LiDAR (light detection and ranging) system that maps the 3-dimensional structure of vegetation and combines it with advanced spectroscopic imaging. By analyzing different wavelengths of reflected light, this imaging reveals an area’s biochemistry in stunningly beautiful 3-D maps from the treetops to the forest floors. However, like most airborne or space-based instrumentation, the CAO is hampered by a lack of on-the-ground data about the chemical properties of rain forest vegetation. The MacArthur grant provides funding for Asner’s team to collect this much-needed information.
“This grant will allow our team to accomplish something that’s never been done before,” commented Asner. “The Spectranomics Project will help us to build a species database in different tropical forests of Africa, Southeast Asia, Amazonia, the Caribbean, and the western Pacific. Information derived from the project will be a huge boost for rain forest mapping, and thus for conservation and management around the world.”
Asner’s team will strategically collect plant samples on foot and analyze their properties to establish a library with chemical fingerprints of thousands of individual species. Spectroscopic measurements will also be performed to link the chemistry to light-reflecting spectra that can later be obtained from the air.
The database will be available on the web for researchers to use and there will be video and other educational materials for public outreach.