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transplants after three years. <br />Differences in soils: <br />There were rather dramatic differences between the two soil types for many of the attributes <br />measured in the experiment, particularly growth (Figure 4). Soil samples from the two soil types <br />were collected and analyzed for organic matter and nutrient content, water holding capacity, <br />chemical, and physical properties. Because the soils were somewhat mixed prior to placement <br />and no soil profile existed, sampling at 1 foot increments was not conducted. Samples analyzed <br />were taken from the entire topsoil depth placed at the site, about 1 in deep. Preliminary data <br />indicate that neither soil type was toxic, except for high electric conductivity in high irrigation <br />treatments for 2006. Nutrient content such as nitrogen did not seem to be related to soil type, and <br />appeared to not be the limiting factor in tree growth. <br />Fresh roto-cleared soils provided adequate sprouting of aspen from residual aspen roots in the <br />topsoil. Limited sprouting occurred from the stored dozer cleared soils. The data suggest that <br />moving fresh soil to reclaimed land could allow for sufficient sprouting of aspen from residual <br />roots without planting. While survival was not significantly different on the roto-cleared (53%) <br />and dozer-cleared (52.5%) soils, average growth on dozer-cleared soils (18.9 cm) was only about <br />two-thirds of that on the roto-cleared soils (29.4 cm). <br />Dozer cleared soil had higher moisture content, suggesting either less ability of the trees to <br />extract the moisture since they were smaller, and/or the dozer cleared soils had better soil <br />moisture holding capacity and/or was less well drained. Visual observations suggested that the <br />dozer cleared soil was more compact and poorly drained as evidenced by water ponding in a soil <br />pit at the site. Roto-cleared soil generally had less moisture available for trees (Figures 5-7). The <br />soil moisture seemed to have no relationship to amount of irrigation, but was somewhat related <br />to biomass; with larger trees and greater amount of weed growth on the roto-cleared soils related <br />to lower soil moisture. Soil moisture was higher at 30-40 cm depth in the soil than at the surface <br />(Figures 8-9). <br />The lower soil moisture content on the roto-cleared soil was perhaps because of the better <br />drainage and greater plant biomass removing water from the soil. Water in this soil was likely <br />less tightly held since this soil was considerably less compact. All these conditions apparently <br />favored growth of aspen trees. <br />Water Chemistry: <br />Data from 2006 confirmed that local pond water used for irrigation was saline. Non-saline <br />potable water from a Hayden, CO, hydrant was used to irrigate the trees in 2007. Carryover of <br />effects of saline irrigation water for 2005-2006 was evident in lower growth of aspen in the high <br />and medium irrigation treatments compared to the low and control treatments. <br />Physiological status: <br />•