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Drones and A.I. hunting down invasive plants at Salt River

Drones and A.I. hunting down invasive plants at Salt River
Posted at 3:41 PM, Aug 12, 2021

The Salt River is under attack from invasive plant species like the ornery Salt Cedar Tree. From a birds-eye view, scientists are spotting their targets using drones to get rid of as many as possible.

The plants come in different shapes, sizes, colors and origins, threatening a fragile ecosystem with ease.

“Our primary objectives are to reduce invasive species,” said Justin Eddinger.

Eddinger with the Center for Adaptable Landscapes at Northern Arizona University is joined by scientists at Arizona State University Thursday at the Lower Salt River. Since March of 2020, the team has spent more than a hundred hours, mapping hundreds of acres, looking for plants like the Salt Cedar, Giant Reed and Stinknet.

These ordinary-looking, non-native species, are on a mission to take over the area.

“That’s going to decrease biodiversity right, if there’s one type of plant, that means there’s less insects, less birds, less wildlife using that ecosystem,” said Eddinger.

Finding them from the ground in the rugged terrain is both tedious and time-consuming. Once combined with machine learning and drones, the project really took off.

“To the human eye, they all look very similar so when we look from above it’s a lot of green,” said Dr. Amy Frazier, Associate professor at the School of Geographical Sciences and Urban Planning.

That’s where Dr. Frazier and geologist Arnold Kedia with ASU come in. They’ve programmed and developed sensor systems to spatially map vegetation, helping to distinguish the good plants from the bad.

“Each plant has a unique spectral signature, so it reflects light in its own unique way,” said Dr. Frazier.

Their systems can tell the difference. They use pictures taken from the air and create three-dimensional images, allowing them to identify different species with a 93% accuracy.

“It has its leaf structure, it grows up to this altitude, it likes places where it’s more moist, some like it dry,” said Kedia. “We’ll put this data together and into the mapping software and tell it to find this plant species with this characteristic.”

What the combination creates are color-coded mapping models that then guide ground crews with the Department of Fire and Forest Management where to go to remove the damaging species. So far the effort has been met with great success, restoring our past beauty, thanks to futuristic technology.

“I’ve seen a reduction in Salt Cedar in the areas that we’ve treated and I’ve also seen an increase in abundance of native species,” said Jacob Draper with NAU.

The project wouldn’t be possible without partnerships with the National Forest Foundation, Tonto National Forest, NAU, ASU, the Department of fire and forest management and many more. To learn more about the Salt River Restoration Project click here