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udrX I • CSU/DMG SHRUB ESTABLISHMENT FIELD TRIALS SENECA II DEMONSTRATION SHRUB PLOTS INTRODUCTION AND GENERAL STUDY DESCRIPTION Shrub establishment demonstration plots were established at the Seneca II Mine, dte Colowyo Mine, and the Trapper Mine in the fall of 2000. The goal of these plots is to evaluate cost effective methods for establishing native shrubs on reclaimed lands. Continued monitoring of the demonstration plots will be critical to make meaningful evaluations of the treatments as many effects may not become appazent for several more years as plant communities progress from anearly-seral to mid- or late-seral conditions (Paschke and Aedenk, 2005). Native shrub establishment on reclaimed lands has been a challenge. Compeddon from herbaceous species and wildlife browsing present significant obstacles to establishment. Introduced cool season grass spades in partiatlar were frequently seeded in the recent past, and stands dominated by these aggressive grasses have suppressed establishment and growth of the slow growing native shrub spades. The uniform replacement of topsoil, at depths ranging from 12-20 ittches, may be another factor contributing to the homogeneous grass community structure. Grasses thrive at the expense of forb and shrub spades. The young shrub plants that do get established aze highly desirable browse for deer and elk. Thus, heavy browse pressure ¢eates another limitation for shrub establishment In an effort to overcome these limitations, the Division of Minuals and Geology (DMG) requested Colorado State University (CSU) to assist with a study plan to evaluate shrub establishment A study design was developed after considerable discussion with representatives from the mining community, • the DMG and the Colorado Division of Wildlife (DOIX~. Three coal mines in northwestern Colorado volunteered to assist with the project be providing personnel, regraded lands for the plots, construction equipment, planting materials, elk proof fenang, and plot maintenance. At each mine, demonstration plots were constructed in the fall of 2000. Five to six treatments were established to evaluate shrub establishment techniques that have commerdal practicality on a lazge scale. The study design took into consideration the possible limitations to shrub establishment The treatments vary a[ each mine to accommodate the reclamation techniques and material availability for each site, but certain similaz treatments were included at each mine. To evaluate the effect of the herbaceous competition, seed mixes were design so that shrubs contributed the majority of the seed mix. Two seed [nixes were evaluated at each mine: 1) a native grass, forb and shrub seed mixture and 2) a seed mixture of unpalatable native shrubs and low-competitive native grasses and (orbs. At each mine, one treatment included alternating strips seeded with only the shrub/forb component of the mix. At the Seneca II Mine, treatments included seedling transplants, for tall shrub spades that have proven to be particularly difficult to establish from seed. Typical topsoil replacement depths varying from 12-20 inches creates an ideal environment for grass establishment. Therefore, the depth of topsoil on the plots was varied to evaluate shrub and forb response to topsoil depths ranging from 0 inches to 20 inches. Composite soil and overburden samples were taken from each treatment at each miae. Cbetall, the soils (topsoil and spoil) at all three-mine sites have good physical and chemical properties. Soil pH ranges from 6.9 to 7.8, macronutrients appeaz to be adequate fox sustained plant growth, organic matter contents aze relatively high (3.7% to 6.3%), salt levels aze low (EC ranges from 0.6 to 7.6 mmhos/cm and SAR ranges from 0.3 to 1.8), cation exchange capadty (CEC) is in normal range, and • textures are clay loam and sandy day loam. Ctvexall, topsoil and spoil at all tnitte sites have favorable characteristics and provide suitable plant growth medium. MR-52 73-17-] July 2005