other studies- Cooper and Lesica (1992) describe a similar 

 limestone fellfield type from alpine areas in southwest Montana. 

 This community type also occurs on limestone ridges along the 

 east side of the Beartooth Mountains and at lower elevations in 

 the Ruby Range of Beaverhead County (P. Lesica, observations) . 



Natural Heritage Program Rank- G3/S3 



Incidental Types 



In addition to the 33 vegetation types described above, six 

 communities were observed that did not fit our classification. 

 Additional sampling is needed to more fully document these 

 communities and to ascertain their status as unique types. 



Within the forest and woodland zone the following three 

 additional communities were sampled: 



1) Pseudotsuqa menziesii - Juniper us osteosperma 



This community was sampled at two mid slope locations on 

 soils derived from limestone parent materials at elevations 

 between 5,200 and 6,200 feet. Vegetation composition 

 suggests that this community is at the ecotone between 

 Pseudotsuqa menziesii forest and Juniperus osteosperma 

 woodland and both tree species are well represented to 

 abundant. Characteristic undergrowth species include 

 Artemisia tridentata , Cercocarpus ledif olius , Aqropyron 

 spicatum , and Koeleria pyramidata . This community type has 

 not been previously described. 



2) Pinus ponderos a - Juniperus scopulorum 



This community was sampled at one mid slope location on 

 soils derived from non-calcareous sandstone parent material 

 at an elevation of 4,300 feet. Sandstone outcrops were 

 abundant. Adjacent vegetation was the ARTTRI/STICOM type. 

 Pinus ponderosa and Juniperus scopulorum were both well 

 represented. Undergrowth species that were v;ell represented 

 included Artemisia tridentata . Aqropyron spicatum , and 

 Bromus tectorum. This community type has been previously 

 described in north-central Montana (Roberts 1980) . Similar 

 communities occur in Wyoming (Bourgeron and Engelking 1992) . 



3) Picea enqelmannii / SCREE 



This community v;as sampled at one upper slope location on 

 steep limestone talus with little soil development at an 

 elevation of 8,600 feet. Adjacent vegetation v.'as of the 

 ABILAS/ARNCOR and ABILAS/RIBMON types. Picea enqelmannii 

 dominates the open tree stratum. Undergrowth species that 

 were well represented included Clematis columbiana , Leucocoa 



35 



