Whether it's for hiking, boating, picnics or fishing, most Alaskans will find any excuse to be outside during the summer. The season is our reward for tolerating months of marginal weather, and we will brave cooler-than-usual temperatures and swarms of no-see-ums in order to enjoy it while it lasts.
Juneau is blessed with multiple trails, parks, and access to spectacular wild places. Sometimes recreational use of such areas can be all too apparent, however. The presence of litter, trampling of streambanks, or muskegs damaged by off-road vehicle use are indications that our love of being outdoors can degrade the fish and wildlife habitat that is so highly valued by locals and visitors alike.
Another potential threat to natural ecosystems is colonization by invasive weeds. Nonnative plants that spread aggressively and reduce biodiversity by creating monotypic vegetative stands, invasive weeds can alter entire ecosystems once established.
In many cases, invasive weeds simply "outcompete" native plants for essential resources such as soil nutrients, water or sunlight. They often are prolific seed producers or effectively spread through rhizomes (roots). Some invasive weeds secrete chemicals that are toxic to animals or humans, or that can alter soil characteristics. One particular example of such a plant is garlic mustard, which secretes a chemical from its roots that kills mycorrhizal fungus, an essential component of forest ecosystems.
Although in some instances weeds are spread by animals, humans are primarily responsible for spreading invasive weeds. We facilitate new infestations through landscaping or gardening practices, efforts to prevent soil erosion (such as along roadways or in areas disturbed by development), and even unwittingly transport seeds on our clothing, shoes, or vehicles. Colonization by invasive weeds often goes unnoticed until it becomes a legitimate problem and the population is difficult to eradicate.
Prevention of spread, coupled with early detection and control efforts, are therefore critical for protecting natural areas from the impacts of weeds. In addition to keeping an eye out for invasive weeds when traveling on trails and in natural areas, following are some suggested actions that you can take to help prevent weeds from becoming established or spreading to wild areas:
Be aware of what plants are on your property and what you are planting.
Be diligent about checking around purchased starts for weeds. Soils imported from other areas may contain weed seeds.
Avoid planting "wildflower" seed mixes, which often include nonnative and/or invasive species.
Be sure to pull, spray, or mow weeds in your yard before they produce seeds.
Do not share unfamiliar plants with neighbors, or transport plants from wild areas to new locations and/or for personal gardens.
Wash boots and clothing after each outing and before going to another location, especially if there are known weeds where you have been.
Information about weeds, including weed brochures and guides, can be obtained through Cooperative Extension Service, the U.S. Forest Service (including the State and Private Forestry office), the USDA Natural Resources Conservation Service, and the Juneau Watershed Partnership. These entities work cooperatively along with other organizations and individuals in our area to identify and locate invasive weed populations, plan and facilitate eradication and control efforts, and provide information to interested landowners and citizens.
Not in My Backyard is a monthly feature about invasive species created by U.S. Forest Service botanist Ellen Anderson. She can be reached at firstname.lastname@example.org.
The Alaska Natural Heritage Program Weed Ranking Project is available online at akweeds.uaa.alaska.edu/akweeds_ranking_page.htm. Contributors to this column will include Juneau Invasive Plant Action, Juneau Watershed Partnership, Forest Service State & Private Forestry and the National Marine Fisheries Service. Others may be added in future columns.