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attributable to annuals, with grasses contributing 197 lbs./acre and forbs providing 56 lbs./acre. Noxious <br />weeds contributed 1.4% or 14 pounds per acre to the average herbaceous production. <br />Perusal of Tables V12 and Chart V4 indicates that the estimated woody plant density in this area <br />was 974 woody plants per acre with the shrub lifeform accounting for 100% of the total. Holly grape <br />(Mahonia repens) was the dominant woody species with 345 plants per acre followed by low rabbitbrush <br />(Chrysothamnus viscidifiorus), mountain snowberry, and mountain big sagebrush (Artemisia tridentata <br />var. paucifiora) at 209, 186, and 184 plants per acre, respectively. <br />The grassland community type in the study area has been divided into two relatively arbitrary sub- <br />types based on whether or not the area was subject to a recent prescribed burn (Sagebrush Reduction <br />area), or is naturally lacking a shrub component or was naturally burned in the past (Grassland). The <br />sagebrush reduction areas are generally located on the relatively flat upland areas surrounded by over- <br />mature stands of mountain sagebrush and just north of the transition zone between mountain shrub and <br />sagebrush zones. Most of the older sagebrush reduction areas now contain enough reinvading <br />sagebrush to be classified as sagebrush, but the more recent areas exhibit only a few plants and <br />therefore, can still be classified as grassland. The naturally occurring grasslands are scattered <br />throughout the study area in small patches. Some of these patches are located along high-elevation, <br />wind-swept ridgelines and summits where thin soils favor grass and forb development over shrubs. <br />Annual bromes have invaded some of the past natural burn areas (especially at lower elevations) and <br />have slowed the re-invasion of sagebrush into these areas. <br />3.3.2 Grassland Reference Area <br />The Grassland reference area is located in the northern uplands on the bench between Collom and <br />Morgan Creeks (see map V1). It appears this area was subject to a prescribed burn approximately 1 to 2 <br />decades prior to sampling and re-invasion of sagebrush has been generally slow compared with burned <br />areas at higher elevations. This area was selected as a reference area because of its easy access, low <br />probability of future disturbance, and it represents an older grassland area unlikely to see extensive <br />sagebrush re-invasion in the immediate future. Review of Table V5 and Chart V1 indicates that the <br />average vegetation cover of the Grassland reference area was 51.85%. Litter and rock provided an <br />average of 30.5% and 0.0% of the ground cover, respectively, while bare ground exposure averaged <br />17.7%. The dominant plant species were western wheatgrass, prairie pepperweed, Sandberg bluegrass, <br />and cheatgrass with 19.4%, 13.3%, 7.6%, and 5.4% of the ground cover, respectively. Perennial plants <br />(excluding noxious weeds) contributed 64% of the total plant cover (33.0% average cover) while annual <br />CIEDAR CREMASS®CKAT93, INC. Page 20 2005 Collom Vegetation Survey