RESULTS 



General Vegetation Overview 



Lowest portions of the study area, generally between 4,000 

 and 5,000 feet, occur in outwash plains and low hills on the 

 south side of the Pryor Mountains. Shrublands dominated by 

 species of sagebrush ( Artemisia tridentata , A. pedatif ida , A. 

 nova , A. spinescens ) , rabbitbrush ( Chrysothamnus nauseosus , C. 

 viscidif lorus ) , saltbush ( Atriplex nuttallii , A. conf ertif olia ) 

 and greasewood ( Sarcobatus vermiculatus ) and grasslands dominated 

 by bluebunch wheatgrass ( Agropyron spicatum ) and cushion plant 

 forbs are the principle vegetation in this zone. Utah juniper 

 (Juniperus osteosperma ) and limber pine ( Pinus f lexilis ) 

 woodlands predominate between 4,500 and 5,500 feet in the 

 foothills and on rocky ridges south of the mountains. Rocky 

 Mountain juniper (J^ scopulorum ) replaces Utah juniper near the 

 Clark's Fork of the Yellowstone River. With increasing 

 precipitation, woodlands give way to Douglas-fir forest which 

 dominates in the montane zone at ca . 6,000 to 8,000 feet The 

 subalpine zone, at 8,000 to 9,000 feet, is occupied by a mosaic 

 of forest and grassland vegetation. Idaho fescue (Festuca 

 idahoensis ) grasslands predominate on gently rounded ridge 

 crests. Warmer, more gentle slopes, often just below these 

 grasslands, support mesic limber pine forests, while cooler, 

 often steeper slopes are dominated by subalpine fir (Abies 

 lasiocarpa ) forests. 



The Classification 



Forests 



1. Abies lasiocarpa / Arnica cordifolia c.t. 



(ABILAS/ARNCOR; subalpine f ir/heartleaf arnica) 



(1 Stand) 



Environment- ABILAS/ARNCOR is a minor type in the study area. It 

 occurs on cool, moist benches and gentle upper slopes above 8,000 

 feet on limestone substrates. Adjacent warmer sites often 

 support Abies lasiocarpa / Clematis Columbiana while colder sites 

 support Abies lasiocarpa / Ribes montigenum . Adjacent non- 

 calcareous sites that are topographically similar often support 

 Abies lasiocarpa / Vaccinium scoparium . 



Vegetation- Abies lasiocarpa is always well represented and Picea 

 enqelmannii , Pseudotsuga menziesii , and/or Pinus contorta may be 

 co-dominant. Undergrowth vegetation varies from herb-rich 

 patches beneath open forest canopies to sparse undergrowth 

 beneath dense canopies. Dominant undergrowth herbs include 

 Arnica cordifolia , Lupinus sericeus, Solidago multiradiata , Carex 

 rossii , and Festuca idahoensis . 



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