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ERO Resources <br />The herb layer of the sagebrush-wheatgrass type has a mean cover value of <br />• 6.7%. The two codominant grasses in this type are Colorado wildrye and <br />western wheatgrass with mean cover values of 1.1% and 1.9%, respectively. <br />[The cover data for western wheatgrass compares with Dastrup's (1963) <br />findings that cover for western wheatgrass has decreased on range depleted <br />by overgrazing from 10 to 2%.3 Other species of grass important in the <br />herb layer include cheatgrass - 1.1%, Sandberg bluegrass - 0.4%, galleta - <br />0.3%, needle -and -thread grass - 0.3%, Junegrass - 0.1% and squirreltail <br />grass - 0.1%. Perennial grasses comprise 82% of the total averaged <br />herbaceous cover. Important forb species present in the sagebrush- <br />wheatgrass type with their respective mean cover values are fleabane - <br />0.5%, globemallow - 0.2%, long -leaf phlox - 0.1% and cushion phlox - 0.1% <br />(Figure 4, Table 6). <br />Mean shrub cover values are 19.9% for the sagebrush-wheatgrass type. Of <br />the above value big sagebrush, the most important shrub in this type, has <br />a mean cover of 17.3%. Other shrubs of descending importance include <br />shadscale - 1%, greasewood - 0.8%, spiny horsebrush (Tetra iia spinosa) - <br />• 0.1%, big rabbitbrush - <0.1%, little rabbitbrush - <0.1% and Gordon <br />saltbrush - <0.1%. Half -shrubs are less important in terms of mean cover <br />values in this community type. Of this life -form snakeweed is most <br />important with an average cover value of 0.6%, followed by petradoria - <br /><0.1%, winter fat - <0.1% and prickly pear - <0.1% (Table 6). Mean shrub <br />density for the sagebrush-wheatgrass type is 11,862 shrubs per hectare <br />(Figure 4, Table 1). Big sagebrush has an mean density of 10,726/Ha <br />followed by shadscale - 424/Ha, little rabbitbrush - 96/Ha, big <br />rabbitbrush - 40/Ha and spiny horsebrush - 35/Ha. Half -shrubs include <br />snakeweed with a mean density of 2,562/Ha and petradoria - 1 AU, <br />Snakeweed is considered an indicator of overgrazing (Costello 1944). <br />Greasewood characteristically occurs along superficial fractures and in <br />places where water is perched. Greasewood is not considered an upland <br />r 1 <br />U <br />species and its occurrence in this landscape position is remarkable. <br />Primary production in the sagebrush-wheatgrass stands is moderate at a <br />mean production of 20.6 g/m2, Grasses account for 70% of the above <br />II.F-35 <br />