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