Weeds in the Wilderness

By Marty Maddalena, Weeds Crew Leader

The Wilderness is undisturbed, untrammeled and beautiful just the way it is, right? Sort of. The Bob Marshall Wilderness Complex as well as every other piece of public and most private land is in a constant battle with noxious/invasive weeds. These are non-native plants that were introduced to the continent in a variety of ways; for instance, purposefully planted as ornamental garden plants, or accidentally as a contaminant in agriculture seed.

If hand-pulling is the chosen method, the full bags of weeds must be packed out by mule.

That’s where the Bob Marshall Wilderness Foundation steps in. Working with the Forest Service we target specific projects and work hard at combating these weed infestations.

This is important for several reasons. Weeds can outcompete native and more desirable plants in many locations. Weeds are specialists at surviving in drought conditions and thrive in disturbed areas (in the wilderness this includes livestock sites, camp sites, trails, burned areas, landslides, avalanche chutes, etc.). Spotted Knapweed (Centaurea steobe) can produce thousands of seeds per plant and the seeds can be viable for up to eight years! Weeds establish quickly and often before native plants, and tie up and utilize nutrients that are necessary for our native plants to thrive. Once these weeds are established they can alter ecosystems and dominate a site.

There are currently two main treatment options used throughout the Bob. The first is mechanical control. This is the good, old fashioned, on your knees, dirt under the nails method. With some patience and a little plant identification training (which you get on our trips!) entire plants are removed by hand pulling. This is effective because it addresses the plant as well as the seeds it produces.

Invasive Yellow Toadflax spreads by rhizomes as far as ten feet away from the parent plant.

Unfortunately not all species are managed well this way. Plants that reproduce with rhizomes, or by their root systems (like Yellow Toadflax, Linarea vulgaris), are hard to manage because if even a little bit of root is left behind that plant will propagate. These plants are more effectively managed by the other option used with the Foundation: chemical control. The Forest Service provides the proper chemicals and rates, and we provide hands-on training for volunteers. This method can be very effective, but obviously spraying chemicals in the wilderness is not something to be taken lightly. We spend a lot of time trying not to overspray and we steer clear from bodies of water and trees that are effected negatively by the chemicals.

Weeds in the wilderness complex are harmful because they are resilient and require multiple years of treatment at the right time of year. The Foundation works hand in hand with the Forest Service to identify and treat sites that are in danger of altering these precious ecosystems, to help mitigate the influence of humans on the natural landscape.