NASA Technology Aims to Save the Forests

Ravenous insects that are smaller than a penny continue to migrate north from the southeast U.S., threatening to destroy millions of pine and ash trees in the northeastern part of the country. NASA scientists have teamed with the U.S.

Forest Service to combat the problem, hoping to save millions of acres of woodlands throughout North America.

Scientists at NASA’s Goddard Space Flight Center in Greenbelt, Md., are using the G-LiHT (Goddard LiDAR Hyperspectral and Thermal imager) airborne instrument — first developed in 2011 — to assist the U.S. Department of Agriculture’s U.S. Forest Service in understanding and combating two types of insects in particular.

The southern pine beetle, a lethal predator of pine trees, currently infests about 1000 acres of land in New York, and is now moving into Connecticut and Massachusetts.

The second species, the emerald ash borer, is considered the worst tree-killer in the United States. This insect is responsible for killing tens of millions of trees in the Northeast already, and has set up camp in 24 other states and parts of Canada.

The G-LiHT device sits inside an airplane’s cockpit over an open camera port that allows it to look down from 1000 feet up at a speed of about 150 mph.

“We’re probably looking at the eradication of most of the ash trees in the United States and Canada,” said Goddard Earth Scientist Bruce Cook, noting that insects like the emerald ash borer “will continue their feast for the foreseeable future.” However, employment of the G-LiHT device (mounted to a Forest Service airplane) should ultimately help. He and fellow scientists from both agencies have been observing forests in Massachusetts, New Hampshire, New York and Rhode Island this summer.

G-LiHT bounces photons off the forest ground and canopy, measuring signs and symptoms of forest health. It monitors insect damage and maps specific areas at risk, creating detailed, 3D images of individual trees, from the trunk to the leaves. With an imaging spectrometer, G-LiHT is also able to see reflected sunlight that is invisible to the naked eye. This helps scientists gather useful information about the trees, such as changes in leaf pigments that plants use for photosynthesis; according to Cook, declining photosynthesis indicates sick trees.

G-LiHT also features a thermal IR camera that works like night-vision goggles to detect heat. It allows identification of infested trees, as they appear warmer when insects girdle their trunks and interrupt the natural flow and transpiration of water.

With a multisensor, G-LiHT essentially operates similarly to a nervous system with different senses, offering numerous points of view.

“One sense cannot totally inform you,” Cook said. “A more complete picture of forest composition and health can be obtained with multisensor instrument packages.”

Observation at ground level is necessary, too, to examine the health of individual trees; this allows the scientists to better interpret the information gathered via the G-LiHT system.

Both the southern pine beetle and emerald ash borer pose “astronomical damages for the forestry industry in costs for postinfestation control, cleanup and replanting,” according to Ryan Hanavan, an entomologist with the U.S. Forest Service.

“We’re literally talking about millions to even billions of dollars in impact to the forestry industry,” Cook said, adding that infestation prevention “could save millions of dollars to municipalities and landowners, who could be responsible for disposing of dead trees.”

Not only are the pests detrimental to the economy, they also jeopardize Mother Earth’s overall health. Unhealthy forests contribute to biodiversity loss, while healthy ones help offset increasing levels of atmospheric carbon dioxide, a known contributor to climate change.