Wyoming Weed & Pest Council: State Wildfires Making Way for Invasive Plants

Over several weeks, wildfires have ravaged northeastern Wyoming, burning nearly half a million acres of land in the Cowboy State and Montana. State firefighters have made progress containing the flames, but the risk of new fires continues as summer rolls on. 

Data from the National Integrated Drought Information System as early as Aug. 13 shows more than one-half of Wyoming is feeling the effects of abnormally dry to severe drought conditions, making the conditions ideal for fires to spread quickly.

Once the flames are extinguished, scorched areas will need time to recover and regrow wildlife. This period of healing, according to the Wyoming Weed and Pest Council (WWPC), is actually one of the most dangerous times for the state’s local plants.

“A lot of times, we can see whole fields of native plants burned away,” says Lindsay Wheat, Albany County Weed and Pest District supervisor. “Those plants need time to regrow naturally. However, there are stronger invasive weeds which move in and establish themselves as the dominant species in the burn area.”

Canada thistle

Canada thistle is a particular problem in Wyoming, often spreading across large swaths of burned soil. The plant is considered one of the worst invasive weeds in the world, given its ability to adapt to its environment more efficiently than native plants. 

The roots of Canada thistle are extensive and allow the weed to outcompete the local plant life for soil, water and sunlight.

“Plants like Canada thistle are ruderal species, meaning they are the first to move in on disturbed land,” Wheat explains. “They are so resilient they have no problem regrowing in burned fields and forests before any other plant. This is a huge problem for native species, but also for our state’s livestock.”

Most animals will not eat the invasive weed due to its prickly features. This allows the plant to spread even further through seeding and pollination, depleting the already devastated natural food sources for livestock and wild animals. 

Beyond areas affected by wildfires, Canada thistle also impacts crop yields and severely hinders farmers’ productivity.

Prevention and eradication

To help stop the spread of plants like Canada thistle, WWPC often partners with the Wyoming State Forestry Division to help assess any damage done by wildfires and identify the potential threat of invasive species hindering the growth of native plants.

“When a fire burns through a particular area, we are often called to help eradicate the noxious weeds which rush in to take up space and soil,” Wheat says. “It’s one of many examples of how different state agencies work together to help keep Wyoming wild and beautiful.”

According to Wheat, spraying affected areas with herbicide is the preferred method WWPC uses to eradicate Canada thistle. 

An article posted by the University of Wyoming recommends thoroughly cleaning boots and equipment when leaving an area with thistles to help prevent the spreading of seeds. 

Use a hoe or shovel to remove isolated weeds before they reproduce in higher numbers.

Overall, prevention remains the best way to stop noxious weeds impeding the growth of native species. 

If individuals notice weeds on their property that seem out of place or chemical intervention is needed to remove noxious species, contact a local weed and pest district for assistance. A list of all of the district offices can be found on wyoweed.org.

Practicing fire safety also helps protect the Wyoming wild. Always be sure to properly dispose of litter rather than burning it, avoid activities involving fire during dry conditions and always properly extinguish any campfire or open flame when finished using it.

“Drought conditions are something we have been regularly dealing with since the early 2000s,” says Erika Edmiston, supervisor of the Teton County Weed and Pest District. “This year hasn’t been much of an improvement, so it is important to be aware of surroundings and be mindful of potential forest fires. Maintaining a healthy population of native plants is critical for the health of our wildlife, livestock and Wyoming as a whole.”

WWPC is comprised of 23 weed and pest districts in the state of Wyoming. The council works closely with the Wyoming Department of Agriculture and the University of Wyoming to keep current with the latest technology and research available in the ongoing management of noxious weeds and pests. The overall mission is to provide unified support and leadership for integrated management of noxious weeds and pests to protect economic and ecological resources in the state.