Give invasive species the brush off

Several new informational signs at Lewis and Clark Caverns State Park are warning visitors about the dangers of invasive plants like spotted knapweed.

The signs inform guests that shoes can carry the seeds off invasive plants, and visitors are asked to remove or brush seeds and burrs off before entering and leaving the areas near the sign.

According to Assistant Park Manager Tom Forwood Jr., noxious weeds are a high level concern and at Lewis and Clark Caverns State Park they spend thousands of dollars and hundreds of employee and volunteer hours fighting weeds each year.

Forwood said they were many years of use in the park before most people realized how big of a problem these plants can be.

"Starting with the mining era at the turn of the 20th century a lot of these plants became established so that by the time efforts were really ramped up many of them had the better part of a century head start in getting established and propagating. Our comprehensive weed program now includes use of chemicals, hand pulling, bio controls (insects that feed on weeds), mowing, monitoring, reestablishment of native plant species, and reducing inadvertent seed transportation. With this program it adds another level of education to our weed management approach," he said.

The signs give residents information about spotted knapweed, a non-native, invasive plant that is considered a "pioneer plant"; which means it establishes quickly in disturbed areas, outcompeting native plants. The signs also inform visitors the plant has alllelopathic properties, meaning that the root gives off a natural herbicide that kills seedlings of other plants growing nearby. They also inform park visitors that spotted knapweed has a taproot, which makes hand pulling an effective method of control. The signs also tell visitors to look out for Canada thistle, Common mullein, and houndstongue.

"Signage and education is an important part of the overall effort. What makes these signs potentially more effective is that they are interactive. When you put a device or some sort unusual addition to the familiar, in this case the boot scrubber, people pay more attention," Forwood said. "If we can educate even a small portion of our trail users from this program and have them take better care of their gear and utilize best practices in regards to noxious weeds then it is a success. A sign is not cheap, but it is much cheaper than the employee hours, chemicals and other methods to fight these plants once they establish. So far I've had several positive comments from visitors on our new signs which is promising."

Forwood stated the decision to place the signs came about from work by their Region 3 State Parks maintenance foreman Scott Harvey, who he said has been at the forefront of Montana State Park's fight against noxious weeds for the better part of a decade and is always and new methods and strategies to fight against these invasive plants.

"He started looking into this program last summer and the process came to completion this spring with the installation of these signs at several Montana State Parks in Region 3. At Lewis & Clark Caverns a group effort by the Montana State Parks AmeriCorps program finally put them on site and ready to use," Forwood said. "These are just one part of a complex strategy that Harvey and others at Montana Fish, Wildlife and Parks are employing to combat an ever increasing invasive plant problem. Montana Fish, Wildlife and Parks is working to take a lead in many areas for fighting noxious weeds across the state and limit their negative impacts upon our lands and economy and these signs are one aspect of that larger plan."