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C.D co ...-1 o n (::") Chapter I II AFFECTED ENVIRONMENT AND ENVIRONMENTAL CONSEQUENCES Nuttall saltbush or black greasewood. Greasewood occurs on sites with high ground water tables. This is an over--simplification in that each community supports several different species. For example, sites dominated by Nuttall saltbush may also support mat saltbush, shadscale, autumn willowweed, galleta, and other species (Ecology Consultants, Incorporated, 1976). Alkali seepweed is often commonly associated with black greasewood. Two shrub communities are defined here because they support somewhat different wildlife species. For example, Brewer's and lark sparrows, and western meadowlarks are more common on sites dominated by black greasewood than on saltbush sites (Colorado Division of Wildlife, 1984). Greasewood occurs between the Stubb Ditch and I-70 while saltbush species are found in borrow areas north of the interstate. Gambel's quail and ring-necked pheasants also use greasewood areas. Wildlife.--Existing habitats that would be impacted by the proposed project are primarily shrubland, and to a lesser degree, tamarisk. Along with various passerine bird and small mammal species, shrublands provide habitat for game species, such as Gambel's quail, cottontail, and ring-necked pheasants. A small flock of chukars occur at one site along the Stubb Ditch. These may be birds from the nearby Bookcliffs seeking open water. However, almost no native shrub vegetation exists within the Price Ditch rights-of-way, and along the Stubb Ditch rightS-Of-way there are small and disjunct patches of shrubs and tamarisk. No population estimates for various species using shrub cover within the Stubb Ditch rights-of-way exist. However, we assume the existing small and isolated patches, that are easily subjected to human disturbance, would have marginal habitat value if measured in actual sustainable wildlife use. An alternative to using population estimates as an assessment technique is presented below. Imoacts Conditions under the no-action alternative would follow current trends of converting agricultural lands to residential and commercial developments, but at a slower rate than experienced during the early 1980's. Current wildlife habitat conditions within the study area are dependent upon the orchards, croplands, pastures, waste areas, natural washes, residential areas, and vegetation associated with ditch banks and rights-of-ways. The rights-of-way and banks of the Price Ditch are intensively sprayed, mowed, and burned for weed control, and thus provide little permanent wildlife habitat. Located along the northern border of the study area, the Stubb Ditch and its rights-of-way support potential habitat, but experience unauthorized human disturbance. If current trends continue, wildlife habitat would eventually be concentrated into isolated sites unfit for agriculture or urban use. The Price Ditch and its rights-of-way currently reflect this trend and provide little habitat value except perhaps where the unlined ditch functions as a travel lane between waste areas or washes. The Stubb Ditch may continue to provide some habitat value in the short term because of its location at the base of the salt-desert shrub rangeland to the north of the study area. However, financial speculators are currently purchasing sites between the Stubb Ditch and I-70. For example, the southwest corner of the I-70 and Clifton interchange is being filled by private landowners in preparation of future development. 23