Those of us that have been around agriculture tend to know about noxious weeds and the potential impacts they can have on the landscape. My parents managed a ranch growing up, so I spent many summer hours pulling spotted knapweed, chopping down houndstongue and burdock and in later years, spraying weeds. I also spent countless hours fishing, riding horseback and enjoying everything ranch life has to offer a kid. Now that I am older, I spend a lot of time enjoying the outdoors and recreating on public lands. Each year, it becomes more and more apparent to me that the general public lacks knowledge about noxious weeds, and frankly, most don’t care or understand the impacts they can have on our beautiful state.
According to Montana State University Extension, Montana’s Noxious Weeds publication, approximately 8.3 million acres or 9% of Montana is covered in noxious weeds. Noxious weeds are described as exotic plant species that can form dense infestations and may render land unfit for agriculture, forestry, livestock, wildlife or other beneficial uses or that harm native plant communities. These weeds are not just a farmer’s problem, they have the potential to invade not only cropland, but can also have detrimental impacts on rangelands and forestlands, and riparian areas. They can increase soil erosion, displace native plants, decrease biodiversity, degrade stream and riverbanks, and decrease available forage for livestock and wildlife. These factors reduce recreation value. Noxious weeds have the competitive advantage over most native plants because many have deep root systems which allows them to get started earlier in the spring and continue to grow later in the year. They also have no natural predators to keep them in check as they do in their native habitat. Generally, noxious weeds have the ability to produce thousands of seeds annually, which can remain viable in the soil for several years. Some plants, such as spotted knapweed, release chemicals that inhibit the growth of other plants, which is believed to give it a competitive advantage. Weeds that invade streambanks and riparian areas, can decrease bank stability by replacing better suited native grasses, shrubs and trees. Lack of bank stability can speed up erosion, increase sediment deposits in the stream, and increase water temperatures by replacing tall stature, native plants. This can have a direct impact on something Montana is noted for, its clean water and blue-ribbon fisheries.
A 2011 article in Montana Outdoors magazine, featured a story called Open Space Invaders. The story mentioned a study in the 1990’s by Mike Thompson (MT Fish, Wildlife and Parks), who found that dense stands of spotted knapweed in native bunchgrass sites reduced available winter forage for elk. “Weed infestations definitely make a difference in elk distribution. If you have more weeds on public lands, elk could move to property where there are fewer weeds.”
Everyone can make a difference in the war against noxious weeds. Many trailheads and fishing access sites have educational signs about noxious weeds. Take a look before heading off on your next hike or float, and keep an eye out for the weeds that are listed. Contact responsible public agencies if you find an infestation. Or if the infestation is small, take a minute or two and hand pull a few. Many weeds can be controlled by hand pulling (gloves are recommended) to ensure the plants don’t go to seed, carry a small bag and pack them out with you. If you find weed seeds, such as houndstongue, on your clothes, gear or your dog, properly dispose of the seeds instead of throwing them on the ground.
Rafting and fishing guides are on the water almost daily, and can be instrumental in fighting the spread of noxious weeds. Guides, and those of us that enjoy recreating on Montana’s waters can make an impact by reporting new infestations or pulling a few weeds when they stop for lunch and educating clients/friends/family about the effects noxious weeds can have on native landscapes.
Prevention is one of the best and most cost-effective methods to fight this growing problem. Here are some final thoughts to consider:
If you plan to travel with pack animals on public lands, it is a good idea to feed the animals Noxious Weed Seed Free Forage (NWSFF) for 3 days prior to taking them on public lands. It is required that you feed certified weed seed-free forage (hay, pellets, etc.) while animals are on public lands.
Thoroughly clean vehicles, including ATV and UTV’s, so seeds are not dispersed to other areas. A Montana State University study showed that seeds can travel 160 miles in dry conditions on a vehicle before falling off. If possible, don’t drive recreational vehicles through weed patches, and stay on designated trails.
Get involved with local county weed districts, or nonprofit conservation groups such as local watershed or weed management groups and volunteer! Check out our local watershed group, Stillwater Valley Watershed Council at http://www.stillwatervalleywatershed.com/.
Some great additional resources are:
Play, Clean, Go- Stop Invasive Species in Your Tracks. http://playcleango.org/
For information on aquatic invasive species go to Montana Fish Wildlife and Parks: Clean. Drain. Dry. http://cleandraindry.mt.gov/What-You-Can-Do
Montana Noxious Weed Education Campaign (MNWEC). https://weedawareness.org/
Sources: *Montana Outdoors, July-August 2011. Open Space Invaders by David Stalling. *Montana’s Noxious Weeds, April 2018 (EB0159) by Monica Pokorny and Jane Mangold. * Washing Vehicles Prevents Weed Spread. MT NRCS fact sheet. August 2017.
USDA/NRCS Columbus Field Office