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Based on a review of these known distributions, previous studies in the area, and required habitat • <br />requisites for the eight target flora, it was determined that few had little potential for occurrence within the <br />study area. In fad, comparison of the life requisites with habitats known from the study area indicated <br />that only a single taxon was a reasonably potential inhabitant of the area's riparian /wetland community, <br />the Arizona centaury (Centaurium arizonicum). <br />Des~oite the low probability for occurrence, sensitive plant surveys were scheduled to be coincidental <br />with optimal stages of anthesis (June -July) to dated the Arizona centaury. Given that the Spring of ;?000 <br />In the vicinity of the study area was drier than normal and somewhat late, conditions for detection oP this <br />sensitive plant was considered optimal. <br />Prior' to implementation of field work, taxonomic descriptions and botanipl drawings of all eight <br />target species were carefully reviewed and committed to memory. In this manner a definitive search <br />image w2~s attained and the unique characteristics facilitating field identification of suspect plants would <br />be most tnarksd. Actual field work involved search patterns in all portions of appropriate habitat within <br />those portions of the study area exhibiting potential project facilities. Search procedures involved slow <br />implementation of qualitative pedestrian transeds and careful visual scanning of the ground surface for <br />any of th,e target species. Although all plant species observed wHhin the vegetation study area were • <br />identified, special attention was given to looking for target sensitive species within appropdate habitats. <br />2.8 Sample Adeouacv Determination <br />Sampling within each community type for ground cover (pastures, irrigated hayfields and dererlid) <br />and production (pastures and irrigated hayfields) was conducted to a minimum of 10 or 15 transeds <br />depending on requirement. From these initial samples, a mean and standard deviation for each variable <br />was calculated. Where statistical testing is required, collodion of an adequate sample (nm„J is typically <br />necessary to insure reliable estimates of the population (e.g., estimates to within 10% of the true mean <br />(N) wtth 90% confidence). Although statistical testing is not a study requirement, the minimum numbers of <br />samples necessary was determined to establish scientific defensibility in all ciratmstances except <br />production from the irrigated hayfields. In this latter instance, data from 10 samples were only used for <br />corroboration of historic yield data provided by area managers. The Cochran formula below was utilized <br />in accordance with direcfives in Colorado's guidelines (1988). When the inequality (n,,,tn s n) is true, <br />sampling c:an be considered to be adequate, and n,Mn is determined as follows: <br />nmin = (t 23 ~ / (0.1x)2 • <br />~~~ 2~.7BwS AsAm¢.~o4Ra, inc. Page 11 Exhibi[ 5 -Bowie Baseline Vegetation Survey <br />