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the level of the f7trv~al feat~r~~e and may include such categories as terrace, active floodplain, side <br />channels, islands, point bars, reattachment bars, etc. Because vegetation patterns along rivers are <br />strongly associated with geomorphic features, a vegetation sampling scheme would be designed <br />to systematically sample the range of geomorphic features identified in this classification. <br />One approach to sampling vegetation is to establish permanent cross-sections, perpendicular to <br />the river channel at pre-determined intervals. Systematically placing transects so that the full <br />range of fluvial environments is represented is another sound approach. The number and <br />placement of cross-sections is usually determined by accessibility, resources, and time. Once <br />cross-sections are located and permanently marked (i.e., with rebar end posts), herbaceous <br />vegetation may be sampled in framed plots placed at regular or random intervals along transects <br />(1-4 m2 is an acceptable range of plot sizes). Alternatively, if time permits, plots may be laid out <br />continuously (belt transects) along a measuring tape from the edge of low water to the landward <br />extent of the riparian zone. Woody vegetation may be sampled using the line-intercept method <br />with visual estimates or measurements using a densitometer. <br />Characterization of important abiotic variables may then be directly related to vegetation in the <br />plots. For example, if rating curves were established for a site, plot specific flood frequency, <br />inundation duration, etc. could be directly related to the elevation/stage of the plot. k7 addition, <br />variables such as soil texture and chemistry could also be gathered. These abiotic factors could <br />then be formally related to plant community composition in the plots. From this, causal <br />explanations for the observed patterns in plant communty composition, age-class structure, and <br />the species or life-history guilds might become more apparent. k7 addition, our confidence in <br />predictions about the probable response of riparian vegetation to changes in driving variables <br />(such asflow-related factors) would increase with such information (Ruble et al. 2005). <br />Understanding the patterns that currently exist along the Dolores River is a fundamental first step <br />in malting flow recommendations. Once a baseline of plant species composition data measured at <br />permanently marked sites is established, the inventories could be repeated amlually or after <br />extreme events (floods or droughts) to refine our understanding of cause and effect along the <br />Dolores River. <br />Changes in flow regime on the Dolores River, flow components, and vegetation <br />Along the Dolores River there have been many biologically relevant changes in flow regime as a <br />direct result of the operations of McPhee dam. The following text does not attempt to assess <br />whether these changes are positive or negative, but rather points out the biological responses to <br />changes in physical factors such as hydrologic and fluvial processes. <br />kldicators of hydrologic alteration analysis was conducted on the Dolores River at Bedrock, CO <br />(USGS 09169500) and at the Dolores River near Cisco, UT (USGS 09180000) gages. Summary <br />statistics were calculated to compare the daily average flow records for pre and post dam periods <br />of time. Flood frequency curves were also fitted to annual instantaneous peak flow data using the <br />log Pearson type III distribution. The magnitudes of recurrence interval flows of interest were <br />estimated from these flood frequency curves. <br />53 <br />