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Scotchman's Gulch Valley Plant Growth Medium Conditions <br />is The following parameters describe plant growth medium conditions in the Scotchman's <br />Gulch valley relative to the cross section location shown in Figure 1 and further <br />described in the valley cross section presented as Figure 4. <br />Depth to Saturation. Based on auger Hole 1 (Figures 1, 2 and 3) extending down from <br />the bottom of the incised channel, the depth to saturation is located approximately 71 <br />inches below the main surface (approx. elev. 6579 feet). Water flowing in the channel <br />seems not to be in direct hydraulic connection with ground water and appears perched <br />on fine textured, sodium - dispersed materials with very limited permeability. <br />Depth of Capillary Fringe. The top of the capillary fringe was determined to be about 41 <br />inches below the 6579 ft. general surface of the existing channel. This suggests a <br />capillary rise of approximately 30 inches, consistent with lower profile material that is <br />(field- estimated) silty clay loam in texture. <br />Depth of Rooting. At the Channel Profile (Hole 2), exposed depth of rooting was 27 <br />inches to 32 inches. Most roots were in the upper 15 inches. Depth of rooting was <br />consistent at the north -most hole (Hole 5) and the hole adjacent to the channel (Hole 3) <br />where the maximum depth of rooting was about 33 to 34 inches. <br />Evidence of Subirrigation. There is no evidence of subirrigation of the general valley <br />surface; rooting depths do not reach the capillary fringe. Present vegetation (outside the <br />sheep corral where nothing grows) is comprised of a planted stand of intermediate <br />wheatgrass (Thinopyrum intermedium) that shows evidence of productivity consistent <br />• with a deep valley bottom soil. That is to say that deep unconsolidated material in a low <br />topographic position has the opportunity and likelihood of collecting run -on surface water <br />from adjacent slopes, storing it in the upper layers, and supporting plant growth <br />somewhat greater than adjacent convex sites with shallower soils. However, were this <br />vegetation to possess root in contact with ground water, the resulting productivity would <br />be distinctly greater than observed. <br />Even in the Scotchman's Gulch channel (incised approx. 5 feet from the general valley <br />elevation), the narrow band of wetland vegetation along the flowing water did not appear <br />to be indirect contact with the saturated zone, located over two -feet below. Contact <br />with the capillary fringe may supplement wetland fringe growth slightly. <br />Other Surface Levels <br />Immediately to the south of the existing drainage channel on the valley transect, <br />elevations rise rapidly onto a surface defined by the presence of gravels likely to be of <br />Pleistocene age. Plant growth is much reduced. Gravel and cobbles composition is <br />high, the test hole (Hole 4, Figures 1, 2 and 3) met rejection at 10 1 /2 inches. <br />