Laserfiche WebLink
r • <br />production exceeds reference area production, the Division could accept the <br />data as a valid demonstration of success (recognizing that the regulations <br />specifying specific sample size requirements and treatment of transect <br />quadrats as subsamples were not in effect at the time of sampling). <br />3. Text from the approved permit reads "Shrub density will not be used to <br />evaluate revegetation success, since the post mining land use is rangeland <br />and pastureland. Rather, the shrub component will comprise up to 5% of the <br />species composition or 2-4 shrubs per meter squared." No mention of the <br />shrubs or shrub component on the reclaimed area was noted in the report. <br />Please include some discussion in the report regarding success in achieving <br />this shrub standard or goal. <br />4. Tables A-4 and A-5, list the production mean field "wet" weights. However, it <br />appears that sample adequacy was calculated using the dry weights as <br />required by the regulations. The dry weights are calculated and recorded on <br />the data sheets in Tables A-9, 11, 13, 15, 17 and 19. For review purposes, it <br />would have been helpful to have a similar table using the dry weights <br />summarized for each of the reclaimed and reference areas. <br />5. The statistical methods and formulas used for the 2006 production <br />demonstrations appear to be appropriate and correct, except the undesirable <br />perennial forb component does not appear to have been defined or removed <br />from the data sets prior to calculation of sample statistics. From the data, it <br />appears that the undesirable forb component was more prevalent in the AVF <br />reference area than the AVF reclaimed area, and was a relatively minor <br />component of the rangeland reclaimed area. The undesirable perennial forbs <br />should be defined. If they are classified as "noxious weeds" on the Las <br />Animas County list, those species need to be removed from each sample <br />observation prior to calculation of sample statistics (mean, standard deviation, <br />variance). This would be the case for cover as well as production, in cases <br />where statistical testing is required to demonstrate success. <br />If you have questions or comments, please call me. <br />Since <br />Kent A Gorham <br />Environmental Protection Specialist 11