Weeds Cost All Valley Residents

By Tanner Dutton Range Management Specialist, Rio Grande National Forest.
First published in the Valley Courier.
During the summer months residents’ eyes are often drawn to showy vegetation on the landscape , on their trips to work, or even in gardens and flowerbeds . More often than they may realize, these bright flowering plants are weeds that can be damaging to soil, wildlife habitat, and agriculture .
A weed is often defined as a plant out of place. A noxious weed has a special definition with legal connotations. The Colorado Sate Noxious Weed Act defines noxious weeds as plants that are non-native and invasive. The Colorado State Noxious Weed Act lists 69 weed species considered to be a threat to the economy and environment of Colorado . Another 21 species are listed on the State’s Watch List.
Sometimes w e e d s a r e b r o u g h t i n , unknowingly, for a specific purpose such as their ornamental beauty or their ability to revegetate a damaged area. Unfortunately, it is later discovered that these species are weeds. Weed seeds can also be brought in inadvertently on equipment and vehicles , in hay, on livestock, and on the bottom of muddy Noxious weeds usually evolve in other regions and ecosystems. When they are introduced to a new area, their competitive ability is enhanced because the limiting factors that kept the species in check in its native land are absent. Noxious weeds are quick to germinate and are usually able to utilize moisture and nutrients much quicker than native species. These factors allow noxious weeds to take over and form monocultures. Invasive weeds often mine resources from the soil to support rapid growth and high reproduction rates, saving little energy for roots. Therefore, there is little to no structure for soil holding or inputs of nutrients, which is a detriment to soil microbes. Many weeds further damage soil by spreading toxins called allelochemicals, which inhibit other species from growing near them. Loss of native vegetation and decreases in native plant diversity can have far reaching impacts to wildlife habitat, livestock grazing, and proper function of the natural ecosystem. Noxious weeds usually have low forage quality, often have defensive structures such as awns or toxins, and are sometimes poisonous to wildlife and livestock.
In addition to damaging native ecosystems, noxious weeds can affect the local agricultural economy by lowering the quality of a harvested crop or impacting productivity by competing with crops for moisture, nutrients, and light.
Public land managers and users, municipalities, counties , private landowners, farmers, ranchers, and the general public must all work together to prevent and manage noxious weeds. Residents can prevent weed introduction by: not planting noxious and invasive species as ornamental plants; stopping weed spread by utilizing weed free hay on public lands for livestock, properly cleaning equipment, vehicles, and tools, and brushing seeds out of pet fur; managing existing weed populations by learning to identify noxious weeds and how to treat them; and treating populations while they are small and before they have formed monocultures.
Some of the most notorious noxious weeds in the San Luis Valley are Canada thistle, perennial pepperweed (tall whitetop), and Russian knapweed . Weeds often planted in flower gardens that have the potential to spread and harm land are common tansy, Chinese clematis, field bindweed (morning glory), salt cedar (tamarisk), Russian olive, oxeye daisy, and yellow toadflax.
Inform local weed management authorities of a weed infestation and they can assist in treatment. Everyone working together can protect the ecology and economy of the San Luis Valley from invasive and noxious weeds.
Contact the SLV Weed Management Association Coordinator at 719-588-3268 or via email at slvwma@gmail. com. Information is also available through the Colorado Weed Management Association’s website www.cwma.org and the Colorado Department of Agriculture’s website www. colorado.gov/ag/weeds. The SLV Weed Management Association is a public and private partnership created to promote awareness and management of noxious weeds through local and regional initiatives in the SLV area with the vision to cooperatively manage and/or control noxious weeds throughout the San Luis Valley Management Area regardless of geographic or political boundaries to promote ecological and economic values.

Posted in Noxious Weeds

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