2008-05-28_REVISION - C1981019 - Laserfiche WebLink

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Rationale for the proposed pre-2008 grazingland standard is relatively straightforward. As explained in the revised permit text, Harner's 1985 study of the overall baseline area revealed that the native area containing the S. Taylor permit exhibits an average of 3 perennial grasses and 1 perennial forb with between 3% and 50% relative cover. Similarly, Cedar Creek Associates, Inc. 2005 study of the Collom area (across 14 separate sample units - including reference areas) also found that the native area averages 3 perennial grasses and I perennial forb with between 3% and 50% relative cover. By definition, reclamation is designed to replace earlier seral stages of a successionally mature community that according to basic ecological precepts are less diverse. Therefore, to provide a minimally acceptable success criterion for the older (approved) reclamation metrics of the pre-2008 grazingland that also did not reflect "restoration ", the grass component of the herbaceous community was reduced by one integer (from 3 to 2). Because reduction of the forb component of the herbaceous community would have meant reduction to zero using this same logic, the alternative was to reduce the minimal contribution range from 3% to I %. Furthermore, the contribution range was not reduced to 2% because forb populations (like shrub populations) do not re-establish well in young reclamation and sometimes take decades to fully establish. However, by forcing 1% composition for the entire life form there would be eventual seed source for increased forb populations. Furthermore, given site-specific knowledge of pre-2008 grazinglands, Colowyo has modified the existing text to remove shrubs from consideration for meeting the diversity requirement. For the post-2008 grazingland, given the new reclamation procedures detailed in the TR-72 document, somewhat better diversity should be attainable than in pre-2008 grazinglands. Therefore, the standards were increased but additional options were also provided to account for possible differing circumstances. With regard to the grass component, "restoration " levels of diversity should be attainable within the first 20 to 30 years of a reclaimed area's existence. Therefore, the number of taxa with between 3% and 50% relative cover was increased back to the original value of 3. However, given the previous statement that it sometimes takes decades for forb populations to re-establish, "restoration " levels for forb populations would be inappropriate for a minimally acceptable success criterion. Therefore, the first option (b) would be for a single species of either forb or shrub to exhibit between 2% and 50% composition. Given the vagaries of reclamation, a second and third option seemed prudent for areas targeting grazingland as a land use. Therefore, the second option (c) was developed (all forbs or all shrubs with between 4% and 50% composition) to cover the circumstances where many forbs and/or shrubs are exhibited in the reclamation, but none have achieved significance. In this case, the overall population of all forbs and/or all shrubs in the grazingland area should contribute a more significant portion of the composition - double the amount for the life form. If more than about 4% composition is contributed by shrubs, the area would most likely be separately delineated as a shrubland community (wildlife habitat land use). Finally, the third option (d) was developed for those circumstances where excellent grass diversity is obtained, but only poor diversity for shrubs and forbs. However, given that the targeted land use is grazingland, such circumstances should still be considered very acceptable. All three options would provide reasonable diversity for a post-mining targeted land use of grazingland. For the post-2008 wildlife habitat, and considering the rationale provided above and responses to comment 429 below, Colowyo has adjusted the recommended diversity success criteria as appropriate.