2011-06-21_REVISION - C1981019 (3)

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C1981019, TR84 Adequacy No. 3 response June 21, 2011 12. Page 4.15-17, picture `Aspen/Tall Shrub Establishment General Location - This picture shows the general location of the proposed aspen/tall shrub field trial area. The area appears to have a north facing, shallow slope that is generally flat and has been disturbed by mining activity. The area is also surrounded by sagebrush steppe habitat. A sagebrush steppe is characterized by low annual precipitation and can be characterized a semi-arid grassland. These conditions are not favorable to the establishment of an aspen community. Aspens tend to occupy sites that are mesic with fine textured soils that are more fertile and they have a low drought tolerance. The Division suggests that a more suitable site for the aspen trial areas be used, such as in the bottom of a drainage. Please consider a relocation of the field trial area and discuss any possibilities. Please show the proposed location of the field trial area on Map 28 or CCC's Reclamation Map. Colowyo's Response: The location of the field trials were specifically discussed and evaluated by DRMS and CDOW staff at the September 28, 2010 meeting and all were in agreement that this location was appropriate for the trials. Due to it's relative elevation compared to the rest of disturbed area across the mine site, this location receives among the highest annual rainfall/snowfall volume within the proposed disturbance and therefore provides the best opportunity to provide adequate soil moisture during the growing season. The area directly below (down-slope to the Northeast) the trial locations is a mix of serviceberry, snowberry, etc. There are examples of aspen stands on North facing slopes of the Western edges of the proposed South Taylor Pit area. The ability to access these locations for monitoring and future replanting activities, in addition to fencing and other implementation considerations make this location ideal for these trials. This location is also the only location in the South Taylor disturbance area available in the near term for any form of reclamation activities, and will provide the most applicable information towards any future activities targeting aspen/tall shrub establishment. Furthermore, perusal of Map 4C shows Aspen and Sage communities in close proximity at multiple locations at higher elevations, especially in the S. Taylor area. The sage communities at these elevations are co-dominated by snowberry. They are the mesic expression of the community as opposed to the xeric expression. Should this Aspen field trial be successful, further evaluation of additional sites will be discussed with DRMS for appropriateness prior to their implementation. The general area targeting the establishment of these field trials has been included on Map 28B and included with this submittal. 13. Page 4.15-18, table `Aspen & Tall Shrub Field Trials Modified Sagebrush Steppe Mix' - The sagebrush steppe seed mix has been modified to reduce the volume of " low shrubs" in favor of the tall shrubs in the mix and the grasses were also reduced to minimize competition while still providing soil stabilization. The tall shrubs that were added to the seed mix (i.e. Acer glabrum and Prunus virginiana) are adapted to more mesic sites than the grasses and forbs in the same seed mix. Please provide a separate seed mix designed for these field trials that contains a low rate of grasses and forbs combined with tall shrubs that are adapted to mesic sites consistent with the conditions associated with aspen groves. This item has been adequately resolved.