Vegetation: The slirub component of the plot is dominated by an open canopy (20-30% cover) of 

 tall Artemisia tridentata ssp. tridentata with lesser amounts of Chysothamnus nauseosus and C. 

 viscidiflorus. There is heavy grass cover, mostly by the introduced rhizomatous Poa pratensis 

 (ca. 60% cover), but the indicative native rhizomatous Agropyron smithii (syn. Pascopyron 

 smithii) is also abundant (ca. 30% cover). The native bunchgrasses Elymus cinereus (syn. Leymus 

 cinerens) and Poa cusickii and the exotic annual Browns tectorum and rhizomatous Agropyron 

 repens (syn. Elymus repens, Elytrigia repens) are also common. The forb component is 

 depauperate and composed of exotic or native weedy species including ^c/7z7/eo millefolium, 

 Capsella bursa-pastoris, Descurainia richardsonii, Lappula redowskii, and Taraxacum 

 officinale. 



Comments: Canyon and creek bottoms in the Ruby Range are heavily impacted by a long history 

 of cattle grazing and trailing, often making it difficult to determine potential natural vegetation. 

 It is hypothesized that much of the land occupied by the ARTTST/AGRSMI community type in 

 the study area and tliroughout southwestern Montana once supported the ARTTST/£/y7;7w.s' 

 cinereus plant association, or at least E. cinereus (syn. Leymus cinereus) was more abundant 

 (Lesica and Cooper 1997). Though Mueggler and Stewart (1980) rate palatability of the tall and 

 coarse bunchgrass E. cinereus as poor to only fair, observations by Lesica and Cooper (1997) 

 show it to be tender and highly desirable in the spring; it is speculated to be a decreaser under 

 intensive spring grazing regimes. 



The S-rank for this type is listed as undetermined because most sampled Montana occurrences of 

 big sage with western wheatgrass have not specified what big sage subspecies characterized the 

 site; these sites have been coded simply as Artemisia tridentata/ AGRSMl and ranked S5. We 

 suspect that most of the sites (certainly those where A. tridentata predominates on the first teirace 

 up from steams), wherein^, smithii and/or E. cinereus are the dominant undergrowth, support the 

 subspecies A. tridentata tridentata. 



Herb-dominated Vegetation 



Festiica idalioensis/Potentilla diversifolia plant association 



(FESIDA/POTDIV; Idalio fescue/variable-leaved cinquefoil; MTNHP rank G3/S3; 2 plots) 



Environment: FESIDA/POTDIV was sampled by two plots in windswept middle to high 

 elevation upperslope positions near the crest of the Ruby Range. The plots have moderate slopes 

 with northwest and southwest aspects at 7,880 and 9,000 feet elevation. Adjacent less wind 

 impacted positions of lower slopes support Artemisia tridentata ssp. vasyana/Festuca idahoensis 

 communities in the south and Abies lasiocarpa, Picea and Pseudotsuga menziesii forest types in 

 the north. 



Soils: The plots are within the Sebud-Hapgood rock outcrop complex, the dominant soil mapping 

 unit of the southern part of the study area (USDA Soil Conservation Service 1989). These are 

 deep, well drained Cryoborolls of colluvium parent material derived from metamorphic basement 

 rocks, mostly quartzite, gneiss and schists. 



Vegetation: The communities have a low growing patterned vegetation varying in species 

 dominance depending on elevation and degree of influence by wind and soil erosion. The 

 bunchgrass Festuca idahoensis is dominant in both plots with around 30% cover. The sedge 



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