CAHNRS NewsCollege of Agricultural, Human, and Natural Resource Science
New professor uses high-tech sensors to study forest threats, resilience
Since boyhood in Holland, Arjan Meddens has loved experiencing the wonders of the forest, firsthand.
Washington State University’s newest forest ecologist is also lifting his vantage point high above the trees, using drones, airplanes and orbiting satellites to discover how our forests can survive devastating fires and insect outbreaks.
Now in his first semester as assistant professor of forest ecology in the WSU School of the Environment, Meddens specializes in disturbance ecology—how forests react to fire, invasive species, altering climate, and other drastic changes.
“I’m naturally curious,” he said. “I love to think about processes and how they work across landscapes and different time periods.”
While much of Meddens’ research involves hands-on work with measuring tape, pad, and pencil in the field, remote sensors play an increasingly important role. High-resolution cameras help Meddens and his students study the color and health of foliage, while Light Detection and Ranging, or LIDAR, sensors, use laser pulses to create 3-D maps of the forest.
These tools help Meddens to understand how forests recover after fires, and predict areas at risk for future blazes and bug invasions.
Attack of the bark beetles
Native to western North America, bark beetles such as the mountain pine beetle normally play a beneficial role by killing weakened trees and spurring renewal of the forest. But multiple dry, hot summers followed by mild winters have led to a population explosion of the insects, which burrow into, attack, and kill lodgepole, spruce, ponderosa pine, and other trees.
In some of the biggest insect outbreaks ever seen in the U.S. and Canada, the bark beetles have killed tens of millions of acres of western forests in the last two decades.
“Once a bark beetle outbreak happens, you can’t defend against it,” said Meddens, who is trying to gain a better understanding of the cycle of bark beetle outbreaks. His research so far has confirmed that forests face a peak outbreak of the pine beetles.
In the field, Meddens inventories outbreak sites, measures trees and surveys their health, and looks for signs of damage and evidence of beetle species. Then, he compares what he sees on the ground with high-resolution satellite imagery and photos from the past. The resulting data helps him predict areas that are vulnerable.
“Our goal is to understand how today’s beetle outbreaks compare to those of the past,” Meddens said. “We want to be able to see them coming.”
Meddens also maps the carbon impact of beetle outbreaks, revealing the added environmental cost of attacks. Healthy trees take in carbon dioxide for photosynthesis, but dead trees release the gas as they slowly decompose.
Forest refuges from fire
Wildfire is another major agent of change in the forest. Fires burn millions of acres annually in the U.S., destroying homes and trees but also clearing the way for new growth. Climate change is believed to be making wildfires worse, lengthening the fire season and increasing their intensity.
Meddens is particularly interested in fire refuges—areas within the fire perimeter that don’t burn. These sanctuaries help repopulate the forest with plants and animals after the blaze.
By understanding how these refuges can withstand fires, Meddens helps preserve vital natural resources.
“As we encounter hotter and more frequent fires, these unburned islands will be increasingly important for maintaining threatened species, such as owls and sage grouse, in the landscape,” Meddens said.
Now training a group of students in ecological methods, Meddens has been exploring ideas in the classroom and the woods this fall. He looks forward to taking his first sensor-enhanced drone flight for WSU next year.
“The forests of the West are so beautiful, and so important to our wellbeing and our way of life,” he said. “I’m excited to be here at WSU, and I look forward to helping future foresters discover new ways for the forest to survive and thrive.”