2008-03-03_PERMIT FILE - C2006085 (13)

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remont County Area, Colorado acres in size. The native vegetation is mainly grasses and scattered pinyon and juniper. Elevation is 3,500 to 6,000 feet. The average annual precipitation is 12 to 14 inches, the average annual air temperature is 50 to 52 degrees F, and the average frost-free period is 130 to 150 days. The surface layer is typically brown very gravelly loam about 3 inches thick. The upper part of the subsoil is 3 inches of very gravelly clay loam over 14 inches of very gravelly loam. The lower 43 inches or more is very gravelly sandy loam. The soil has a high content of finely divided calcium carbonate below a depth of 6 inches. It is neutral to a depth of 6 inches and is moderately alkaline below that depth. The surface layer is very cobbly or very stony loam in about 20 percent of the unit, mainly along the outer edges of the mapped areas. Included with this soil in mapping are areas of Kim soils in swales. These soils make up about 5 percent of the unit. They are not gravelly. Also included are small areas of soils that have a layer of loam about 10 to 30 inches deep over gravelly sandy loam. Permeability is moderate in the Sedillo soil. Available ter capacity is low. Effective rooting depth is 60 ches or more. Runoff is slow or medium, and the hazard of water erosion is slight or moderate. This soil is used as rangeland. The potential plant community is mainly blue grama, needleandthread, Scribner needlegrass, and pinyon. The average annual production of~air-dry vegetation is about 850 pounds per acre. If the condition of the range deteriorates, red threeawn, blue grama, rabbitbrush, and broom snakeweed invade or increase. Range seeding is suitable if the range is in poor condition. Broadcast seeding generally is necessary because of cobbles and pebbles on the surface. This soil is well suited to homesite development. The capability classification is Vls, nonirrigated. The soil is in the Gravelly Foothill #214 range site. 102-Seitz gravelly fine sandy loam, 20 to 40 percent slopes. This deep, well drained soil is on north-facing mountainsides. It formed in alluvium and colluvium. The native vegetation is mainly conifers. Elevation is 8,200 to 11,500 feet. The average annual precipitation is 16 to 25 inches, the average annual air temperature is 38 to 42 degrees F, and the average frost-free period is 40 to 60 days. The surface is typically covered with a thin layer of rtially decomposed needles, leaves, and twigs. The urface layer is pinkish gray gravelly fine sandy loam about 15 inches thick. The upper 9 inches of the subsoil is very gravelly clay loam. The next 10 inches is very cobbly clay. The underlying material to a depth of 60 75 inches or more is very cobbly sandy clay loam. The soil is neutral. In some areas the surface layer is very cobbly loam or very stony loam. Included with this soil in mapping are areas of Larand soils on the upper part of side slopes. These soils have a surface layer of very gravelly fine sandy loam. They make up about 10 percent of the unit. They have less clay in the subsoil than the Seitz soil. Permeability is slow in the Seitz soil. Available water capacity is moderate. Runoff is rapid, and the hazard of water erosion is very high. This soil is used as woodland, for wildlife habitat, or for recreation. The potential plant community is mainly Douglas-fir and some Engelmann spruce and an understory of mountain muhly, elk sedge, Kentucky bluegrass, buffaloberry, and common juniper. The potential production of native understory vegetation is about 250 pounds per acre. This soil is suited to production of Douglas-fir. The site index for Douglas-fir is about 45. Harvesting some of the mature trees for sawtimber and thinning dense stands of the younger trees for use as poles increase the growth rate of the rest of the stand and increase the understory vegetation. The soil is suited to limited production of Christmas trees. The slope limits felling, yarding, and road construction. Conventional harvesting methods generally are restricted to areas that have slopes of less than 30 percent. Measures that minimize erosion should be applied when landings, roads, and skid trails are established. Unless disturbed areas are carefully protected, the hazard of erosion is high. Properly designing road drainage systems and carefully placing culverts help to control erosion. Spoil from excavations is subject to rill and gully erosion and to sloughing. Installing water bars on roads, landings, and skid trails and reseeding after harvest help to stabilize grades, cuts and fills, and other disturbed areas. Suitable seeding mixtures include smooth brome, orchardgrass, and intermediate or pubescent wheatgrass. Chiseling or otherwise disturbing the surface helps to provide an adequate seedbed. Seeding late in fall helps to ensure that soil moisture will be adequate for the establishment of seedlings in spring. Because of the high content of rock fragments, planting seedlings is difficult. If plant competition is not a limitation, the mortality rate of 2-year-old seedlings is about 25 to 50 percent. The planting techniques used and local variations in climate greatly influence seedling survival. Plant competition delays natural regeneration but does not prevent the eventual development of a fully stocked, normal stand of trees.