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Section 4 <br />Delineating and Prioritizing Colorado's Environmental and Recreational Resources and Needs <br />Among the riparian and wetland conservation targets <br />tracked by CNHP, 97 are vascular plants and more <br />than 270 are plant communities. Only a subset of these <br />tracked targets occurs in any one river basin. Tracking <br />by CNHP confers no legal status; only a few plants <br />and no communities have legal status, e.g., <br />Endangered Species Act listing. The plants shown in <br />Figure 4-11 include those with fewer than 100 known <br />populations in the world (imperilment rank Gl-G3) <br />and have fair to excellent estimated viability (A-C <br />viability rank). Locations of plant communities with <br />conservation value include both rare (Gl-G3) <br />communities with A-C viability rank as well as more <br />common communities (G4 and G5) with excellent <br />estimated viability (A rank). The species or plant <br />community is ranked from A through D, where A <br />indicates excellent estimated viability and D indicates <br />poor estimated viability. For example, an A-ranked <br />occurrence might be a large willow stand in the <br />headwaters of the Yampa River where flows are <br />unaltered from natural flow, there are few weeds, and <br />the surrounding landscape is natural. A D-ranked <br />occurrence might be a small cottonwood stand on the <br />Arkansas River where flows are used for multiple <br />purposes and tamarisk is abundant Based on the <br />Natural Heritage Methodology, all locations included <br />on the maps have conservation value. <br />Data included on these maps have been collected <br />over the past 2 decades by a wide range ofnot-for- <br />profitand agency scientists working on many types <br />of projects. However, most data have been collected <br />by CNHP scientists during efforts to classify <br />Colorado's riparian and wetland vegetation and <br />during county-wide surveys for potential <br />conservation areas. CNHP data collection efforts <br />began in 1990 and continue through the present. <br />Although CNHP data indicate much about what <br />occurs in an area, they do not necessarily indicate <br />anything about areas where nothing is mapped. <br />Blank spots on the map can occur either because <br />there really is nothing of conservation value there, or <br />simply because the area has not been evaluated. <br />Also, mapped locations are only the known areas <br />with conservation value; these data in noway <br />suggest that because an area is not mapped, it is not <br />important. <br />Wildlife <br />Wildlife coverages depicting distribution <br />information were originally developed for the SW SI <br />Phase I by the Colorado Division of Wildlife <br />(CDOW) and updated for this Phase 2 effort <br />(Table 4-2 and Figures 4-12 through 4-24). Each <br />species map delineates the current distribution of <br />the species based on actual field sampling within the <br />designated stream or lake. Point sampling data for <br />stream populations have been evaluated by using the <br />best professional knowledge to expand and define <br />the stream reach that is most likely to be occupied <br />by the species. These delineations represent the <br />CDOW's best attempt to describe the habitat that is <br />known to be populated by the species at specific <br />sampling sites and reaches in between those sites. It <br />must be recognized that due to temporal and spatial <br />distribution characteristics of the species, all <br />segments along the entire stream reach may or may <br />not be populated by the species at any given time. <br />Furthermore, the streams and lakes designated as <br />specific habitat describes only those waters where <br />the species has been recently sampled (last <br />25 years). The total habitat for the species is not <br />necessarily limited or fully described by this <br />depiction. CDOW is expected to refine occupied <br />habitat locations as time and resources allow for the <br />completion of species surveys of all potential <br />habitat. <br />Hydrologic Unit Code (HUC)10 and HUC 12 <br />distribution polygons are included to illustrate the <br />drainages that are connected to habitat that is <br />currently occupied by the species. These larger <br />geographic units are known to have or are likely to <br />possess habitat attributes that provide for the <br />protection or continued persistence of the species <br />populations within those units. The HUC 10 and 12 <br />areas provide the user with a visual representation of <br />terrestrial areas that have the potential to affect the <br />habitat for each species that may be considered by <br />the CDOW. <br />In response to requests for data and map products, <br />field sampling data for aquatic species in the State of <br />Colorado were drawn in part from the aquatic <br />relational database that, in some cases, contains <br />FINAL DRAFT 4-9 <br />