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<br />Chapter II I
<br />
<br />AFFECTED ENVIRONMENT AND
<br />ENVIRONMENTAL CONSEQUENCES
<br />
<br />Aaricultural Lands.--Farming practices and crops grown in the
<br />proposed project area generally reflect conditions within the Grand Valley.
<br />Principal cash crops include fruit (apples, peaches, pears, apricots, and
<br />cherries), corn, barley, and other grains. Alfalfa and corn ensilage are
<br />the main forage crops. The irrigation facilities that support most
<br />agricultural land uses also provide some diversity to cultivated areas.
<br />Canals and ditches, such as the Price and Stubb Ditches, carry water to the
<br />farms. Smaller on-farm ditches carry water to fields where it is typically
<br />spread through furrows. Furrow irrigation is most common, with some
<br />sprinkler and drip irrigation systems also in use.
<br />
<br />While some crops supply food and cover, it is the small areas of
<br />farmland that are not regularly cultivated that provide the majority of
<br />habitat value to farmland wildlife. These areas, often referred to as
<br />"edge", are defined as the natural vegetation found along fence rows,
<br />roadsides, irrigation laterals and canals, and other sites escaping
<br />disturbance. Vegetation includes scattered cottonwood trees and willows.
<br />Agricultural edge is particularly important to ring-necked pheasants.
<br />Existing conditions and potential impacts to on-farm edge habitat and
<br />species using such sites have been addressed in Stage Two studies (Bureau
<br />of Reclamation, 1986a and Colorado Division of Wildlife, 1984).
<br />
<br />Wetlands.--Two types of wetland vegetation are found within the
<br />proposed Unit area. Marshes (emergent wetlands) are supported by water
<br />seeping from canals and ditches, and are characterized by common cattail,
<br />bulrushes, coyote willow, baltic rush, alkali muhlenbergia, common spike
<br />rush, inland salt grass, and other species. Marshes often exhibit distinct
<br />zonation dependent on level of water, inundation, soil moisture, and soil
<br />salinity (Ecology Consultants, Incorporated, 1976). Aquatic species
<br />(common cattail, coyote willow) are generally found submersed at the
<br />wetland's interior, surrounded by bulrush, baltic rush, and common spike
<br />rush, which are in turn surrounded by alkali muhlenbergia, and smooth
<br />horsetail. Very saline sites may support inland saltgrass, while alkali
<br />seepweed and Haloaeton alomeratus are found on salt encrusted areas just
<br />outside the marsh. Small mammals found in these wetlands include the
<br />western harvest mouse, deer mouse, long-tailed vole, and house mouse. Bird
<br />species include the red-winged blackbird, song sparrow, and shore birds.
<br />Marshes located within the proposed project area have been previously
<br />addressed in Stage Two studies (Bureau of Reclamation, 1986a). The primary
<br />functions and values of marshes in the Unit include sediment removal,
<br />wildlife habitat, and esthetics. No marshes occur along either the Price
<br />or Stubb Ditches.
<br />
<br />Tamarisk or other wetland shrubs are the other wetland association
<br />found in the proposed project area. Tamarisk dominates cottonwood and
<br />other slow growing species on disturbed sites subjected to high water
<br />tables, soil salinity, fire, flooding, and grazing (Ecology Consultants,
<br />Incorporated, 1976). Willows are common in small seepage areas along the
<br />ditches. Other plants commonly found with wetland shrubs include Russian
<br />olive, inland saltgrass, alkali sacaton, cheatgrass brome, and Kentucky
<br />bluegrass. Common species that use these areas include the robin and
<br />mourning dove. The values of wetland shrub areas include wildlife habitat
<br />and esthetics.
<br />
<br />Shrubland.--For purposes of this analysis, desert shrub associations
<br />are characterized by their dominant plant member; in this case either
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