Extension Viewpoints: The cost of noxious weeds


By Ethan Proud
PREVIEW Columnist

Who really cares about noxious weeds? A select group of weed managers? Ranchers? While many people may not actively participate in weed control or even understand what invasive species can do to an ecosystem or a property, everyone should care. 

Noxious weeds degrade native communities, alter migration routes, increase the frequency of fires and may harm human health. 

But they are plants, how can they be bad? Many supporters of weeds will argue that it’s a plant and it is serving some role in the ecosystem, but invasive plants are biological litter. They would not have established a foothold without help from humans. The damage they cause is a direct result of human activity. 

In their native range, they compete with other plant species, pathogens, insects and animal herbivory. In their invaded ranges, they have left their competitors behind, and our native plants and animals have not adapted to their presence. These means that without human interference, they will run rampant and create dense monocultures that outcompete other plants. 

The key to a healthy environment is a diversity of plant species to support multiple mammal, bird, reptile and insect species (this also means that a lawn of Kentucky bluegrass is not a healthy environment). 

A 2014 study by W. Marshall Frasier conducted by the Colorado Weed Management Association, Colorado Departments of Natural Resources and Agriculture, and Colorado State University addressed the cost of noxious weeds in Colorado. The article is titled “Economic Impact of Invasive Weed Species in Colorado.” 

Loss of value was calculated by three use components: the average economic value of uninvaded parcels, proportion of diminishment of economic value due to the presence of 10 weed species and the proportion of invaded land which displaced value activity. The product of these three values identifies the cost of weed presence. 

The total cost of these 10 species was $13,838,920 when the costs to agricultural land, wildlife habitat and recreational lands were combined. The data that was considered in this report came from one source: county weed managers. 

Mapping is voluntary and not all programs have weed districts, meaning that the data has many gaps and should be considered a conservative report. This analysis did not take into consideration the cost of controlling noxious weeds by private landowners and public agencies, but rather the degradation of value to land due to the presence of noxious weeds. Simply put, noxious weeds by virtue of being here cost Colorado nearly $14 million before control measures are considered. The cost of doing nothing to control weeds is monumental.

Archuleta County Weed and Pest is your local resource for managing noxious weed populations and controlling other pests.

Upcoming event

June 3, 4 to 6 p.m.: Shred Day. Downtown TBK Bank parking lot. Donations support Archuleta County 4-H programs. NAID Certified. The cost is $5 per box.