31. Chrysothamnus nauseosus / Erioqoniim brevicaule c.t. 



(CHRNAU/ERIBRE; rubber rabbitbrush/short-sten buckv/heat) 



(3 stands) 



Environment- CHRNAU/ERIBRE is common on moderate to steep, highly 

 eroded slopes, often in badlands terrain on the south and west 

 sides of the Pryor Mountains. Elevations range from 4,200 to 

 5,000 feet Adjacent communities on gentler slopes include 

 ARTPED/AGRSPI and ARTTRI/AGRSPI . Utah juniper woodland may also 

 occur nearby on ridgetops with fractured bedrock. 



Vegetation- These stands are characterized by lov.' vegetal cover. 

 Chrysothamnus nauseosus v;as present in all stands but had a mean 

 cover of only 3%. Gutierrezia sarothrae was present in most 

 stands with mean cover of 2%. Atriplex conf ertif olia is often 

 present. Agropyron spicatum was the only common grass, occurring 

 in half of the stands with mean canopy cover of 7%. Oryzopsis 

 hymenoides occurs in some stands. Eriogonum brevicaule was 

 present in nearly all stands and had mean cover of 8%. Arenaria 

 hookeri is common in some stands, and Machaer anther a 

 qrindelioides is present in many stands. Cryptogamic soil crusts 

 are v.'ell-developed in some of the stands on gentler slopes. 



Soils- CHRNAU/ERIBRE occurs on deep soils derived from shale, 

 bentonite, clay or sandstone interbedded v.'ith clay. Surface 

 gravel and cobbles are common and texture is sandy clay to clay. 

 We collected no additional soils data for this type. 



Other Studies- CHRNAU/ERIBRE probably corresponds to Knight et 

 al.'s (1987) nixed desert shrubland. ECON (1975) describes a 

 similar badlands community in southeastern Montana v.'here 

 Eriogonum paucif lorum replaces E_^ brevicaule as the most common 

 f orb. 



Natural Heritage Program Rank- G2/S2 



32. Festuca idahoensis - Agropyron caninum c.t. 

 (FESIDA-AGRCAl-I; Idaho fescue-bearded v.'heatgrass) 



(3 stands) 



Environment- Upper slopes and broad ridges near the crest of the 

 Pryor Mountains are often occupied by mesic high-elevation 

 grasslands. Elevations range from 8,000 to 8,800 feet On 

 gentle, warm slopes these grasslands often grade into mesic 

 limber pine forests at lower elevations, while on cooler slopes 

 or the highest areas, Abies lasiocarpa and Picea engelmannii 

 dominate adjacent communities. 



Vegetation- Shrubs are rare in this type although Artemisia 

 f rigida r.ay be locally common in protected sites at lower 

 elevations. Festuca iaahoensis , Aarcpvron caninum and Koeleria 



33 



