microphylla were some of the many common forbs present in this 

 type. 



Pinus f lexilis stands with a dense understory of shrubs such 

 as occur in the study area are prone to severe crown fires with 

 high P_s_ f lexilis mortality (Fischer and Clayton 1983) . It is 

 likely that much of what is now limber pine woodland was 

 sagebrush steppe before active fire suppression (see discussion 

 below under Arttri/Fesida) . 



A large proportion of the limber pine occurring on the 

 limestone ridge at the north end of the study area had infections 

 of dwarf mistletoe. In some areas administered by BLM, ca. 50% 

 of the limber pine were dead or dying. 



Shrublands and Grasslands 



Shrub steppe dominated by species of Artemisia occur in the 

 lower foothills at the base of the Line Creek Plateau on the east 

 side and, to a limited extent, on the north side along Rock 

 Creek. Elevations range from 5,700 ft to 7,500 ft. These 

 communities have undoubtedly been affected by livestock grazing 

 and fire suppression, both of which would result in an increase 

 of shrubs. Portions of this area have experienced fire in the 

 past five years. Studies are currently underway to elucidate the 

 role of fire in structuring vegetation of the region (K. Reid, 

 pers. comm.). Classification of shrublands follows Mueggler 'and 

 Stewart (1980) . These authors place Artemisia nova in synonymy 

 under A^_ arbuscula . Most authorities recognize these taxa as 

 separate species, and I have followed their treatment (e.g., Dorn 

 1984) . 



(16) Artemisia tridentata / Festuca idahoensis h.t. 



Lower slopes along the foothills on the north and east sides 

 of the Line Creek Plateau are occupied by shrublands dominated by 

 Artemisia tridentata and cool season bunch grasses such as 

 Festuca idahoensis , Aqropyron spicatum , A. dasystachyum and Stipa 

 comata . Common forbs included Artemisia friqida , Cerastium 

 arvense , Lupinus sericeus and Balsamorhiza incana . 



This community occurs intermixed with Pinus f lexilis 

 woodland. Fire destroys both the P^_ f lexilis and the understory 

 of A^ tridentata . The resultant Festuca - Aqropyron grasslands are 

 then reinvaded by A^ tridentata and eventually P^. f lexilis . 

 Thus, the Pinus f lexilis / Festuca idahoensis , Artemisia 

 tridentata / Festuca idahoensis , Artemisia nova / Festuca idahoensis , 

 and Festuca idahoensis / Aqropyron spicatum "habitat types" in the 

 east foothills of the Line Creek Plateau form a dynamic mosaic 

 dependent on fire frequency . It may be that the entire area 

 would be considered potential P_^ f lexilis woodland under 

 atypically long fire-free intervals. 



