18 



may eventually be necessary here, to protect the 

 seepage area. At the North Fork Birch Creek site, a 

 hiking trail (#105) traverses all three seepage 

 areas which contain C. passer inum . and could 

 eventually lead to destabilization of the slope (D. 

 Field, U.S. Forest Service) . 



The reported occurrence along Straight Creek (012) 

 apparently consists of subpopulations that are close 

 to the hiking trail (#212). The full extent of this 

 occurrence, and the potential impacts from trail 

 use, need to be more fully documented. 



3. TIMBER HARVESTING: The only population known to 



have been impacted by timber harvest activity is the 

 Green Timber Basin (002) site. In this area, some 

 clearcutting has occurred adjacent to the existing 

 orchid site, and it is possible that the population 

 was partially removed by this activity. The forest 

 which currently contains the population was 

 selectively logged, and some direct impacts to 

 individuals probably occurred as a result. 



The two other sites in the Front Range, outside the 

 Bob Marshall Wilderness Area, which could 

 potentially be impacted by timber harvesting include 

 Blacktail Gulch (006) and Dry Fork Lange Creek 

 (007) . However, it did not appear that such 

 activities are imminent. 



B. MANAGEMENT PRACTICES AND RESPONSE: Little detailed 

 information exists regarding the response of C. 

 passerinum to management practices such as grazing and 

 timber harvesting. Owing to its specialized habitats and 

 complex obligate interactions with soil mycorrhizal 

 fungi, it is not likely that the species would respond 

 favorably to such activities. Although the population in 

 Green Timber Basin contained a maximum of 160 stems in 

 1988, it was probably larger in the past. Ecodata 

 studies recently established at this location will be 

 useful in obtaining a more detailed understanding of the 

 species' response to disturbance. 



C. RECOMMENDATIONS FOR MAINTAINING VIABLE POPULATIONS: The 

 following recommendations are made to insure the long- 

 term persistence of viable populations of C. passerinum 

 on U.S. Forest Service lands in Montana: 



1. Protection of natural habitats which currently 



support populations. Although afforded some degree 

 of protection by wilderness designation, the four 

 populations in the Bob Marshall Wilderness Area 

 should be considered in any proposed recreational 

 developments which may occur in the vicinity of the 



