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<br />002733 <br /> <br />Opportunities for Ecological Improvement Along the Lower Colorado River <br />Mark Briggs and Steve Cornelius <br />7/24/97 <br /> <br />areas that are likely to experience significant agricultural runoff. Both sites receive <br />runoff from adjacent agricultural fields during the hot, dry summer months. This <br />seems to have had a remarkable effect on survival and growth rates of planted trees. <br />At the Dredge Spoils site, for example, the riparian vegetation planted on the levee side <br />immediately adjacent to the agricultural fields appear much healthier and seem to have <br />experienced greater growth rates those on the opposite side of the levee. <br /> <br />Future revegetation efforts should take advantage of similar opportunities. Moreover, <br />it has been noted that establishing native, riparian plants immediately adjacent to <br />farmland can provide useful habitat for a variety of avian species, helping to <br />compensate for avian habitat loss in other areas (Anderson et al. 1988). <br /> <br />Take advantage of sites that are inherently more mesic <br />Old river meanders and other low elevation topographic features can be characterized <br />by relatively high water availability. Such areas can offer ideal conditions for the re- <br />establishment of native, obligate riparian plants and should be considered for future <br />revegetation efforts. At the No Name Lake site (site #1), the only obligate riparian trees <br />to establish and grow were those planted in the relatively low elevation of the lake's <br />depression. <br /> <br />Develop recovery projects with a long-term outlook <br />All too often recovery efforts fail simply because there was no technical expertise or <br />funding available follOWing project completion. By its very nature, restoration has a <br />long-term time frame. Success is therefore measured over a protracted time period, <br />requiring an institutional backing that needs to persist beyond the possible departure of <br />individuals. At the very least, the design of the recovery effort needs to include <br />funding and personnel for maintaining irrigation systems and fences, controlling exotic <br />plants, replacing lost plant materials, and monitoring results for three years following <br />project completion (monitoring should continue over a longer time frame). <br /> <br />2. Identify and Protect Existing Wetland Ecosvstems <br />In both the delta and the lower reaches of the Colorado River there remains significant <br />areas occupied by native, wetland habitat The cottonwood-willow riparian forest at <br />the confluence of the Gila and Colorado Rivers, the Cienaga de Santa Clara, and the <br />marshlands of the Rio Hardy are examples. Whether these areas were created naturally <br />or artificially, with intent or completely by accident, their protection should be a clear <br />short-term priority for lower Colorado River conservation efforts. Additional existing <br />natural areas should be identified and plans to maintain or enhance their ecological <br />condition should be developed. <br /> <br />The Cienaga de Sa1!:ta Clara <br />The Cienaga de Santa Clara exemplifies this priority. The cienaga is maintained for the <br />most part by drainage flow from Arizona's Wellton-Mohawk canal. Since the canal's <br />completion in 1978, the cienaga has grown from 200 hectares (estimated in 1973) to <br /> <br />Page 21 <br />