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Dowe Flats Quarry Noxious Weed Management Plan 4.4.1 Grazing CEMEX has successfully used goats for noxious weed control since 2004. Goats will eat all of the noxious and nuisance species found on the Lyons Quarry property at almost any stage in the plant development. However, they are most effective for control when the plants have not gone to seed. Goats will eat the flowers, stems, leaves, and seeds and prefer the weeds to the grass species in the reclamation areas. Cattle have also been used to graze some of the leased pastures outside of the mined area. Cattle will only eat most of the noxious species when they are in the young rosette stages, this is especially true for the thistles and knapweeds that develop spines as they mature. With both goats and cattle, but especially with cattle, it is important to closely manage and rotate the heard to achieve weed control without overly impacting the desired vegetation. Cattle, unlike goats, will show a preference for grasses over many of the noxious species. 4.4.2 Insects & Plant Diseases The CDA maintains several host -specific insect species at their Palisade Insectary that can be purchased for biological controls (Table 1). CEMEX has introduced a stem -boring weevil to control Dalmatian toadflax and has seen the population of this species decrease over the past several years. Future insect releases will be coordinated with the CDA's Insectary and will comply with State and local requirements. Table 1: Insect biocontrol species available from CDA Noxious Weed Species State List Insect Control Species Insect Type Purple loosestrife A Hylobius transversovittatus Weevil, root feeding Canada thistle B Uro bora cardui Fly, stem galls Dalmatian toadflax B Mecinus janthinus Weevil, stem boring Diffuse kna weed B Larinus minutus Weevil, seed head feeding Leafy spurge B Aphthona nigriscutis, A. cyparissiae & A. czwalinaellacertosa Beetle, root & leaf feeding Musk thistle B Trichosirocalus horridus Weevil, crown -feeding Spotted kna weed B Cyphocleonus achates Weevil, root boring Tamarisk B Diorhabda spp. Beetle, leaf feeding Puncturevine C Microlarinus lareynii & M. ly ri ormis Weevil, seed -feeding Weevil stem -boring Field bindweed C Aceria malherbae Mite, leaf galls 4.5 Cultural Control One of the best ways to manage wide -spread weed species such as those on Colorado's C -List is to establish a vigorous, self-sustaining native vegetation community. Germination and establishment of noxious weeds can be reduced by following accepted revegetation and vegetation management techniques that favor the growth of desirable plants. These include: • Prompt seeding and revegetation of disturbed areas with appropriate seed mixtures, • Maintaining optimum fertility and moisture levels, • Planting at optimum density of pure live seed ("PLS"), Habitat Management, Inc. 7 September 2015