USDA/USFS Listed Invasive Plant Species: References: University of Nevada Cooperative

Extension—”Measures to Prevent the Invasive Plants Spread of Noxious and Invasive Weeds During Construction Activities”

of Coconino  Cheat grass (Bromus tectorum), in photo USFS/Coconino National Forest - http://www.fs.usda.gov/coconino/ Diffuse knapweed (Centaurea diffusa) County Leafy spurge (Euphorbia esula) Other resources: Field bindweed (Convolvulus arvensis) The Arboretum at Flagstaff - Management During Scotch thistle (Onopordum acanthium) http://www.thearb.org Building Project Russian thistle (Kali tragus) San Francisco Peaks Weed Construction Sweet clover (Melilotus officinalis) Management Area - Dalmatian toadflax (Linaria dalmatica) http://www.swvma.org/ sanfranciscopeakswma.htm Kochia (Kochia scoparia) Prickly lettuce (Lactuca serriola) Coconino County Cooperative Extension - Foxtail barley (Hordeum jubatum) http://extension.arizona.edu/invasive- Common mullein (Verbascum thapsus) plants

Poison hemlock (Conium maculatum) Contact Us

Coconino County Community

Development

2500 N Fort Valley Rd Building 1 Flagstaff, AZ 86001

(Above: Field bindweed; right: 928-679-8850 Scotch Thistle) www.coconino.az.gov All photos credit of USDA

What is an invasive plant species? Best Management Practices:

A species is defined as invasive if it is  It is best to remove a weed at an imma- nonnative to an ecosystem and its introduc- ture stage. Mechanically remove (hand tion changes environmental conditions, caus- pull, etc.) weeds that are young to not es economic losses due to landscape degra- disturb multiple layers of soil. dation, or causes harm to human health (Executive Order 13112, 1999 - USDA). In-  Dispose of all flowering weeds by incin- Weed Management During Construction: vasive plants have expanded populations erating them or transport them to an with increasing large-scale soil disturbance  Before disturbing the project grounds, take appropriate disposal location in sealed, associated with development and severe inventory of current weed infestations and thick bags. It is not adequate to compost prioritize treatment in project areas and along fires. them at a typical residential site. access points. Areas with noxious weeds should be treated prior to construction. Contact the Arizona’s Natural Resources  Areas treated to remove noxious weeds Why remove invasive plants species? Conservation Service to learn how to map should be revegetated with native spe- weed populations on your property (602-280- cies. 8808). Invasive species compete directly with native species for water, sun, and soil nutrients. By  Operate and stage in an area that is not  Utilize seed and other plant materials not managing invasive plants, we are allow- infested with weeds as much as possible to that have been checked and certified as eliminate further contamination. ing them to potentially out-compete northern noxious weed-free and have a weed Arizona’s plant communities and harm deli-  Avoid or limit traveling in areas that are weed content of 0.5% percent cate processes that support the biodiversity infested, or go through an area where seed spread is less likely to occur.  After seed or transplants are installed, we see in Coconino County. Invasive plants area should be mulched immediately to can increase the likelihood of soil erosion,  Clean construction equipment before arriving prevent erosion, prevent new establish- decrease wildlife habitat quality, and contrib- to a project site and when leaving. Ensure that equipment is clean of dirt or any seed ment of weed species, and to conserve ute to the decline of endangered and threat- harboring media. water. Most likely, more weeds will ened species (National Wildlife Federation).  For seed and straw material, make sure it is emerge from the soil. Proactively re- certified as weed-free. moving these weeds after treatment will

make a site’s restoration easier and less  In areas with canopy vegetation, retaining the canopy may help shade/suppress further laborious. weed establishment and growth.  Herbicide may be worth considering for  Avoid creating soil conditions that promote situations where invasive plant popula- weed germination and spread (excessive tilling, etc.) tions cannot be mechanically removed due to site conditions or available man-  Minimize soil disturbance to the extent power. Consult with local experts who consistent with project goals. understand the specific species’ life Left: Diffuse Knap- weed (Centaurea cycles in which you are managing and diffusa). Above: Leafy with experts who are certified in Spurge (Euphorbia esula). Photos: USDA herbicide applications.