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JACK30N COUNTY AREA, COLORADO 66
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<br />Dry Mountain Loam range site
<br />
<br />This range site is the most extensive in the Area. This
<br />site consists of moderately deep and deep, well drained
<br />soils. The surface layer is moderately coarse textured
<br />to medium textured. Slope ranges from 0 to 25 percent,
<br />but it is mostly 2 to 15 percent. Permeability is mostly
<br />moderate to moderately rapid, and available water ca-
<br />pacity is low to high. Winter is extremely cold, and
<br />summer is cool. Annual precipitation is 9 to 18 inches;
<br />about two-thirds of this normally falls during the grow-
<br />ingseason.
<br />The potential plant community is 15 percent stream-
<br />bank wheatgrass, 10 percent sheep fescue, 10 percent
<br />muttongrass, 8 percent pine needlegrass, 5 percent
<br />Letterman needlegrass, 3 percent Sandberg bluegrass,
<br />and 5 percent ~unegrass, bluebunch wheatgrass, squir-
<br />reltail, and Nevada bluegrass. The grasses form a
<br />sparse stand beneath an open stand of big sagebrush,
<br />which makes up 15 percent of the community. Brtter-
<br />brush makes up 5 percent of the community, and low
<br />rabbitbrush makes up 3 percent. The community is also
<br />3 percent lupine, 3 percent pussytoes, 3 percent aster,
<br />3 percent fleabane, 2 percent yarrow, 2 percent blue-
<br />bells, 1 percent buckwheat, 1 percent phlox, and 3 per-
<br />cent fringed sage, snakeweed, and other forbs.
<br />The high proportion of grasses in the potential com-
<br />munity makes this site suitable for grazing cattle.
<br />Heavy grazing by cattle causes grasses, such as blue-
<br />bunch wheatgrass, sheep fescue, pine needlegrass,
<br />muttongrass, Nevada bluegrass, and Letterman needle-
<br />grass, to decrease and other plants, such as big sage-
<br />brush, blue grams, and the less palatable forbs, to
<br />increase.
<br />Condition of the range vegetation can be improved,
<br />and forage production increased, by use of planned
<br />grazing systems, proper grazing practices, fencing,
<br />and brush management where needed.
<br />The estimated total annual production of air-dry
<br />plant material ranges from 600 pounds per acre in poor
<br />years to 1,000 pounds per acre in good years. About
<br />400 to 650 pounds per acre is suitable forage for cattle.
<br />Valley Bench range Bite
<br />This range site is extensive. It is on benches and up-
<br />lands. This site consists of deep to shallow, well drained
<br />soils. The surface layer is moderately coarse textured.
<br />Slope ranges from 0 to 30 percent. Permeability is mod-
<br />erate or rapid, and available water capacity is low to
<br />high. Winter is extremely cold, and summer is mod-
<br />erately cool. Annual precipttation is 9 to 16 inches;
<br />about three-fourths of this falls during the growing
<br />season. This site is slightly more droughty than Dry
<br />Mountain Loam range site. The dry growing season
<br />strongly influences the kind and amount of potential
<br />vegetation on this site.
<br />This site has a scrubby big sagebrush aspect. The
<br />potential plant community is 20 percent streambank
<br />wheatgrass, 15 percent muttongrass, 10 percent june-
<br />Figure 13.-Area of Mountain Loam range Bile, which ie at outer edge of park floor where rainfall ie higher; Gellcie sandy loam.
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