10 



Lithic Cryoborolls are most likely (Montagne et 

 al. 1982) . 



6. Dependence of this taxon on natural 



disturbance: A number of the C. lonqistylum 

 populations occur in areas which have been 

 lightly disturbed in the past through timber 

 management, grazing or road maintenance, 

 however, other populations occur on sites that 

 are relatively remote and pristine. The plant 

 does not appear to be disturbance dependent. 



C. Biological characteristics. 



1. Vegetation physiognomy and community structure: 



Cirsium lonqistylum occurs in open meadow 

 communities that are dominated by grasses and 

 forbs, but often include scattered Potentilla 

 fruticosa . indicating moderately mesic 

 conditions. 



2. Regional vegetation types: According to 

 Kuchler (1964) , the populations in the Little 

 Belt Mountains fall within the Douglas fir 

 forest zone. 



3. Frequently associated species: Cirsium 

 lonqistylum populations occur in both disturbed 

 and undisturbed habitats. The disturbed 

 habitats are typically roadsides, trails, 

 meadows and clearings. Species associated with 

 the disturbed sites include: 



Artemisia spp. (sagebrushes) 



Bromus inermis (smooth brome) 



Phleum pratense (timothy) 



Poa pratensis (Kentucky bluegrass) 



Cirsium arvense (Canada thistle) 



Taraxacum officinale (common dandelion) 



The undisturbed habitats are native grasslands and 

 grassy openings in open forests. Associated species 

 include: 



Juniperus communis (common juniper) 

 Pinus contorta (lodgepole pine) 

 Pinus ponderosa (ponderosa pine) 

 Pseudotsuqa menziesii (Douglas fir) 

 Potentilla fruticosa (shrubby cinquefoil) 



k Achillea millefolium (yarrow) 



" Aqoseris qlauca (pale agoseris) 



Allium qeyeri (Geyer's onion) 



i 



