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• 4.4.1.7 Shrub Establishment Test Plots <br />Introduction and General Study Description. Shrub establishment demonstration plots <br />were established at Trapper Mine during the fall of 2000. The test plots were established <br />in cooperation with the Colorado Division of Minerals and Geology (DMG) and <br />researchers with Colorado State University (CSU). The goal of the plots was to evaluate <br />cost effective methods for establishing native shrubs on reclaimed lands. <br />Native shrub establishment on reclaimed lands in northwest Colorado has been a <br />challenge. Competition from herbaceous species and wildlife browsing present <br />significant obstacles. The uniform replacement of topsoil, at depths ranging from 12-20 <br />inches, may be another factor contributing to the homogenous grass community structure. <br />Grasses thrive at the expense of forb and shrub species. The young shrubs that do get <br />established are highly desirable browse for deer and elk. Thus, heavy browse pressure <br />creates another limitation for shrub establishment. <br />In an effort to overcome these limitations, a study design was developed. Six treatment <br />plots were established to evaluate shrub establishment techniques that have commercial <br />practicality on a large scale. The specifics of the Trapper demonstration plots are <br />presented in the Field Trial Details section of this narrative. <br />The study design took into consideration the possible limitations to shrub establishment. <br />To evaluate the effect of herbaceous competition, seed mixes were designed so that <br />• shrubs contributed the majority of the seed mix. Two seed mixes were evaluated: 1) a <br />native grass, forb and shrub seed mixture and 2) a seed mixture of unpalatable native <br />shrubs and low-competitive native grasses and forbs. One treatment included alternating <br />strips seeded with only the shrub/forb component of the mix. The depth of topsoil on the <br />plots was varied to evaluate shrub and forb response to topsoil depths ranging from 0 <br />inches to 20 inches. <br />Composite soil and overburden samples were taken from each treatment. Overall, the <br />soils (topsoil and spoil) had good physical and chemical properties. Soil pH ranges from <br />6.9 to 7.7, macronutrients appear to be adequate for sustained plant growth, organic <br />matter contents are relatively high (4.8% to 6.5%), salt levels are low (EC ranges from <br />0.6 to 1.6 mmhos/cm and SAR ranges from 0.6 to 1.8), cation exchange capacity (CEC) <br />is in a normal range, and textures are clay loam and sandy clay loam. Overall, both <br />topsoil and spoil have favorable characteristics and provide a suitable plant growth <br />medium. <br />To evaluate the impact from wildlife browse, elk proof fencing was constructed on one- <br />half of each treatment. <br />• <br />4-124 <br />I . .: - Zoo <br />Approvk?d• <br />APPROVED MAY 27M