other studies. — This type has been described in Montana by 

 Hansen et al. (1991). 



19. Agropyron smithii Type 



(AGRSMI; western wheatgrass; G4 S3) 



Vegetation. -- Agropyron smithii forms abundant cover within 

 this type. Other species that may be well represented with 

 greater than 5% cover include Carex stenophylla , Koeleria 

 cristata , Poa pratensis , and Equisetum hyemale . 



Physical Setting. — This type occurs on alluvial parent mater- 

 ials on flat flood plains in wide valley bottoms at elevations 

 around 5000 feet. Litter cover equals or exceeds 50% of the 

 ground surface. The soil surface is generally stable with no 

 evidence of accelerated erosion. 



Soils are often very deep with sandy loam to clay tex- 

 tures, have a high available water holding capacity, and are 

 non-calcareous. Many of the soils are alkaline. Coarse 

 fragment contents are generally low. 



Adjacent Communities. --Adjacent wetter communities are usually 

 graminoid dominated, while adjacent drier sites often feature 

 communities in the Artemisia tridentata series. 



Other Studies. — This type has been described in Montana by 

 Hansen et al. (1991). 



20. Elymus cinereus Type 



(ELYCIN; basin wildrye; G4 S2?) 



Vegetation. — Elymus cinereus dominates (often with a total 

 canopy cover of 100%) . Juncus balticus and Poa pratensis may 

 be well represented. The total cover of additional species 

 seldom exceeds 5%. 



Physical Setting. — This type occurs on gravelly alluvial 

 parent materials on flat terraces in wide valley bottoms at 

 elevations around 5500 feet. Litter cover equals or exceeds 

 60% of the ground surface. The soil surface is generally 

 stable with no evidence of accelerated erosion. 



Soils are often Mollisols, are very deep with loamy 

 textures, high available water holding capacity, and are non- 

 calcareous. Coarse fragment are generally absent. 



Adjacent Communities. — Adjacent wetter communities often 

 feature the Salix exigua type while drier uplands are often 



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