Remote sensing gives new look at forest diversity

Generating comprehensive and accurate tree inventories is key to understanding forest population dynamics and using that information to manage the land. But those inventories in even the smallest forests can mean weeks and months in the field, identifying and measuring individual trees by hand.

johncouture.jpg
John Couture

Purdue University scientist John Couture participated on a team that used aerial hyperspectral remote sensing platform to identify trees in a diverse forest plantation, and to understand the role of tree diversity on forest productivity. The team, led by the University of Minnesota, published its findings in the journal Nature Ecology & Evolution.

The chemical and physiological differences in plants allows scientists to classify them based on how they’ll reflect light. Then algorithms can take data from an aerial platforms or satellite images and match those light signatures to plants.

“Light interacts with vegetation in somewhat predictable manners based on the chemical, physiological and internal structure of the leaves and in the canopies themselves,” said Couture, an assistant professor of entomology and forestry and natural resources. “When we measure the light reflected off those leaves, we can start to determine which species of tree we’re seeing.”

Couture and his colleagues are interested in using remote forest identification tools to understand forest productivity. In general, it’s believed that the more diversity in a forest, the more productive the forest. When diversity is high, all species tend to grow larger than they would on their own. However, that isn’t the case when one species dominates an area.

“Sometimes you see a particular tree species dominate the canopy, and it might be that species drive over-yielding, where one species outcompetes all the others” Couture said. “We can see from the data we’re collecting whether there is a complementary effect, meaning trees are using resources more efficiently, or an over dominance effect. And we can start to understand how different combinations of tree species will provide different outcomes.”

That’s key for developing tools that can help plantation owners and foresters better manage the health of their forests.

“Right now, this is giving us a look at the health of a forest stand and using this information, we can possibly make more informed decisions about where to harvest and where to plant new trees,” Couture said. “If we can expand this to natural systems, we’ll be able to determine diversity levels without having to go in and census trees. It will help make more timely and accurate decisions for maintaining the health of those forests.”

Featured Stories

Meghan Hartman by statue with children at the Celery Bogg Nature Center.
From classroom to camp: Purdue student’s AmeriCorps summer service term inspires environmental stewardship

As dawn breaks over the Celery Bog Nature Area, Meghan Hartman, a sophomore in Natural Resources...

Read More
yellow agave flower sprout from the giant flower stalk against a clear blue sky
The death bloom of a century plant

Agave americana, also known as the century plant, has evolved for a dry desert life. For 30...

Read More
4 students stand in front of marshall porterfield, all in different space and NASA shirts, one carrying a plastic jug with a white fungus growing over a mycoponics tube inside. Grow tents line the background on each side.
Mushrooms in space: Purdue researchers invent mycoponics to cultivate fungi for Earth, the moon and beyond

Porterfield founded MycoGravity — the Purdue Innovates Office of Technology...

Read More
Ag Barometer
After 3 months of decline, farmer sentiment rebounds in July

After three consecutive months of decline, farmer sentiment rebounded as the Purdue...

Read More
Majid Kazemian in his lab, standing in front of a desk, smiling.
Majid Kazemian named 2026 University Faculty Scholar

Majid Kazemian, professor in Purdue University’s Departments of Biochemistry and Computer...

Read More
Graphic with a slanted picture of the chemical fire and ash on the ground inside Purdue Branded Black and Gold bars
Extension steps up: Where do communities turn after disaster?

On Saturday, Sept. 6, 2025, a fire started in a chemical company on the outskirts of Newburgh, a...

Read More