Early detection helps states control invasive species before it’s too late

Rising temperatures continue to fuel climate change-related disasters like hurricanes and drought with little sign of stopping. In fact, last month was the hottest July on record in the U.S., with July 3 marked as the hottest day in history until the record just a day later. While residents lament over scorching temperatures, many invasive species thrive in warm climates. That’s why concerns over an increase of invasive species around the nation are heating up.

As non-native plants invade new areas, state officials worry about their effects on local ecosystems, infrastructure and recreation. Japanese knotweed, an invasive plant commonly found in the Northeast along roadsides, wetland areas and waterways, for example, can damage highway and water infrastructure, according to a 2021 report from the U.S. Transportation Department. It can grow up to 8 inches per day and quickly block lines of sight at intersections and stop signs. When the plant’s roots expand, they can weaken the integrity of or even cause fractures in road pavement and concrete on bridges. Stormwater and septic systems are also vulnerable to knotweed damage. 

The plant also poses a more general, but equally serious climate threat, said Bethany Bradley, a professor of biogeography and spatial ecology at the Department of Environmental Conservation at the University of Massachusetts Amherst. Where it grows, water permeates the ground at slower rates, leading to drier soil that increases the risk of floods and erosion. With natural disasters projected to increase in coming years as a result of climate change, invasive species like Japanese knotweed could compound those consequences, she said. Flooding isn’t the only negative impact of invasive species. 

Cheatgrass, another nonnative plant mainly invading the Great Basin region in the western U.S., is notorious for being flammable, worsening the spread of fires. Nevada recently felt the fiery effects of cheatgrass when California’s York Fire crossed state lines, burning more than 80,000 acres last week.

Knowing where invasive species crop up as early as possible can help managers minimize the consequences of noxious vegetation, Bradley said, and understand the relationship between climate change and the spread of nonnative species. “You can translate that [data] back onto a map of what the future climate conditions are likely to be, and that can give you a sense of [invasive species] risk right now, and what risk looks like 20 years, 50 years [or] 100 years, which, from a management perspective, can help with advanced planning,” she said. 

In the West, for example, Utah is battling an invasive reed called phragmite that has taken over the Utah Lake shoreline. Phragmites create a fire-prone landscape and often impede recreation and rescue efforts, requiring land management officials to annually spray affected areas with herbicide to control the phragmite. To better identify where treatment is needed and to track treatment progress, the Utah Division of Forestry, Fire and State Lands, or FFSL, and other state agencies use geographic information systems to map the phragmite landscape. 

Last year, phragmite coverage was reduced by 74% with improved monitoring, herbicide treatments, revegetation and other efforts. The state is also exploring how drone imagery and artificial intelligence could be used to enhance the identification management of invasive species in wetland areas, FFSL Senior GIS Analyst Gabriel Svobodny said. 

Using drones for invasive species management has already taken off in Washington. This summer, the state’s Fish and Wildlife Department launched an initiative to deploy drones to map the location of and spray harmful plant species like cattail and reed canarygrass with herbicide. 

In Michigan, non-native aquatic vegetation such as Eurasian water milfoil and starry stonewort have proven to be thorny problems. They crowd out native plants, filtering nutrients out of the water and interfering with fish predation. Additionally, they can impede recreational activities and clog residential or industrial water intakes. Like most invasive species, these plants grow fast and are expensive to control. In fact, treating invasive aquatic plants is estimated to cost Michigan about $24 million a year, William Keiper, an aquatic biologist in the water resources division of the Michigan Department of Environment, Great Lakes and Energy, told Route Fifty in an email.

“[T]he aquatic invasive plants we are most concerned about invading Michigan are well established in states further south because of such favorable growing conditions in those warmer climates,” he said. “As the climate continues to warm and our cold winter months decrease, the potential for Michigan to become a favorable place for these species to thrive is a concern.”

But the Wolverine State is putting up innovative defenses to protect its native environment. For instance, the state is partnering with researchers to explore early detection technology that identifies the environmental DNA, or the genetic material shed by organisms in water, of invasive plants, Keiper said. Early detection can help managers develop solutions before the damage reaches an unsalvageable point.

Michigan’s Natural Resources Department is also a part of the Midwest Invasive Species Information Network, or MISIN, a data-sharing effort led by the Michigan State University. The network aims to enable the development of effective invasive species control strategies. For instance, researchers developed the MISIN app that residents can download to upload photos of invasive species they find in the wild to support officials’ detection and response efforts. The app also provides data on more than 400 invasive plant and animal species found in the Midwest so users can better educate themselves on what wildlife to watch out for. 

“Thinking outside the box and being adaptive are often needed when dealing with invasive species as they are resilient and often challenge managers,” Keiper said. “[I]f an invasive species becomes established, it is unlikely eradication will be as simple as just pulling it out of the ground or capturing it with a net.”  

Managing invasive species “is like weeding your garden,” Bradley said. “If you have a small patch of weeds in your garden, and you go out and treat it … then the rest of your plants are probably doing just fine. But if your entire garden is taken over by weeds, that's a huge, huge effort to transform it back into whatever you are trying to grow in the first place.”