communities occur in Idaho and Wyoming (Bourgeron and Engelking 

 1992) . 



Natural Heritage Program Rank- G3/S3 



12. Juniperus osteosperma / Artemisia tridentata c.t. 



(JUNOST/ARTTRI; Utah juniper/big sagebrush) 



(6 Stands) 



Environment- JUNOST/ARTTRI is generally found on southwesterly 

 slopes at elevations between 4,000 to 5,500 feet. Upslope 

 vegetation often features the Pinus flexi lis - Juniperus 

 osteosperma type. Downslope vegetation is often of the Artemisia 

 tridentata / Aqropyron spicatum or the A^ tridentata / St ipa comata 

 types. 



Vegetation- Juniperus osteosperma is the only tree present and 

 Artemisia tridentata is alv;ays well represented in the 

 undergrowth. The only other species exceeding 1% cover on 50% or 

 more of the study plots are Aristida purpurea and Poa sandberqii . 

 Combined bryophyte and lichen cover is generally less than 5% of 

 the ground surface. 



Soils- Soils underlying the JUNOST/ARTTRI type are generally 

 derived from calcareous sandstone. Combined cover of gravel and 

 rock on the ground surface averages 60% and bare soil cover 

 averages 20%. The soil subgroup at our single soil 

 characterization site v;as a Ustic Torriorthent . The single pH 

 measurement was 8.0, and conductivity was 202 uhmos/cm- (1 

 stand) . 



Other Studies- This type has not been previously described in 

 Montana. Similar communities occur in Arizona, Colorado, Idaho, 

 New Mexico, Nevada, Utah, and Wyoming (Bourgeron and Engelking 

 1992) . 



Natural Heritage Program Rank- G5/S3 



13. Juniperus osteosperma / Cercocarpus ledifolius c.t. 



(JUNOST/CERLED; Utah juniper/curlleaf mountain mahogany) 



(8 Stands) 



Environment- JUNOST/CERLED is found on dry, rocky ridges and 

 slopes at elevations around 4,500 to 5,000 feet. The type 

 integrades to Cercocarpus ledifolius / Aqropyron spicatum and 

 commonly adjoins the Juniperus osteosperma / Aqropyron spicatum 

 type. 



Vegetation- Juniperus osteosperma is the only tree species 

 present (canopy cover averages around 10%) . The undergrov.-th is 

 dominated by Cercccarous ledifolius . Aqropyron spicatum is 



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