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Dowe Flats Quarry Noxious Weed Management Plan • Minimizing use of fertilizers, • Selecting suitable species for revegetation, and • Minimizing areas of disturbance and exposed soil to prevent opportunities for aggressive species to establish. CEMEX has a detailed revegetation plan in the mining permit that has been approved by both DRMS and Boulder County. This revegetation plan utilizes native species that are well -adapted to the site and revegetation management practices designed to provide competition with noxious weeds. 5 Existing Noxious Weed Infestations The basis for IWM is that no one treatment will be effective for all noxious species. The treatments vary by species, season, and site conditions. Table 2 outlines the best timing for various chemical and mechanical controls as well as species palatability to goats and cattle. Diffuse knapweed, musk thistle, common teasel, bull thistle, and common mullein are biennial forbs that reproduce by seeds. Biennial species typically take two years to complete their life cycle. These species will germinate in the fall or spring and will produce seed from June through August of their second growing season. First-year rosettes should be treated with appropriate herbicides throughout the growing season to prevent bolting and seed production. In the event that they do produce seed, hand cutting of the seed heads and their removal from the property is the most effective treatment. Canada thistle, Dalmatian toadflax, and field bindweed are perennial forbs that reproduce by seed and root sprouts from extensive root systems. Plants should be treated with appropriate herbicides during active growth periods to prevent seed production. Treatment in the fall is critical to ensure translocation of herbicides to the extensive root systems. All of these species are palatable to goats and most are palatable to cattle during at least part of their growth cycle. Grazing animals can be used to control perennial and biennial weeds when grazing is timed to prevent the production of seeds and the intensity and duration of grazing are carefully monitored to prevent overgrazing. CEMEX has had success with goat grazing for weed management in the past. Treatment of cheatgrass is not required under the Colorado Noxious Weed Act, but can be necessary when it is inhibiting the establishment of the desirable plant community that is required for bond release under DRMS rules. Cheatgrass is a winter annual species that germinates in the late fall or early spring. Pre -emergent herbicides can be applied in the late summer or fall to prevent germination or kill seedlings without impacting establishment of desirable species. Post -emergent herbicides can also be used after germination, but before seeding. Large infestations can be mowed prior to seed set and some dense infestations may need to be mowed prior to herbicide application to remove the dead annual vegetation and litter to allow for effective soil contact of the herbicide. Habitat Management, Inc. 8 September 2015