quartzite and shales are also parent materials supporting this 

 type. Surface gravel is cominon to abundant. The soil subgroups 

 at our three soil characterization sites included a Lithic Ustic 

 Torriorthent, a Ustic Torriorthent , and a Ustollic Haplargid. 

 Surface texture ranges from loam to clay-loam. In our stands pH 

 varied from 7.3 to 7.8., and conductivity ranged from 201 to 237 

 uhmos/cm^ (3 stands) . 



Other Studies- Kratz (1988) reports this community type in the 

 same study area. Knight et al. (1987) describe a black sagebrush 

 steppe for the Bighorn Canyon NRA. This type is also reported 

 for southwest Montana by Mueggler and Stewart (1980) . Their type 

 ( Artemisia arbuscula / Agropyron spicatum ) , which was described 

 from areas with higher rainfall, commonly has higher vegetation 

 cover and greater species richness than our stands. Similar 

 communities are described for much of the Intermountain West 

 (Mueggler and Stewart 1980, Franklin and Dyrness 1973, Jensen et 

 al. 1988, Bourgeron and Engelking 1992). 



Natural Heritage Program Rank- G5/S4 



18. Artemisia pedatif ida / Aqropyron spicatum c.t. 

 (ARTPED/AGRSPI; birdfoot sagebrush/bluebunch wheatgrass) 



(3 stands) 



Environment- ARTPED/AGRSPI is a minor type in the study area, 

 usually occurring on gentle to moderate slopes at 4,700 to 5,100 

 feet in the outwash plains and lower foothills. It is most 

 abundant west of Crooked Creek. Adjacent communities on better 

 drained soils are often dominated by Artemisia tridentata , while 

 on heavier or more saline soils Atriplex nuttallii and Aqropyron 

 smithii are important species. 



Vegetation- This type has a sparse cover of low shrubs with 

 scattered clumps of grass intermixed. Artemisia pedatif ida had a 

 mean canopy cover of 17%. Artemisia tridentata and Ceratoides 

 lanata were the only other frequent shrubs with mean covers of 2% 

 and 1% respectively. Aqropyron spicatum was the only common 

 grass with a mean canopy cover of 21%. Forbs are not abundant, 

 but Allium textile , Arenaria hookeri and Phlox hoodii are 

 frequent species. Soil lichens are present but not abundant. 



Soils- ARTPED/AGRSPI occurs on deep soils derived from shales or 

 sandstone interbedded with shale or clay. Surface texture is 

 clay loam to clay. We collected no additional soils data for 

 this type. 



Other Studies- Kratz describes an Artemisia pedatif ida / Aqropyron 

 spicatum community type that probably includes both our 

 ARTPED/AGRSPI and ARTPED-ATRI\'UT types. Knight et al. (1987) do 



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