16 



symbiotic relationship with certain soil 

 fungi (mycorrhizae) for effective seed 

 germination and subsequent growth. If the 

 necessary mycorrhizal fungi are lacking in a 

 particular area, it is not likely that a 

 species such as O. rotundifolia could become 

 established on such a site. 



G. POPULATION ECOLOGY 



1. BIOLOGICAL INTERACTIONS 



a. COMPETITION: Owing to its specialized 

 habitat, O. rotundifolia would probably not 

 possess strong competitive ability in other 

 more densely vegetated areas to which it is 

 not ecologically adapted. However, within 

 the microhabitats where it does occur, 

 individuals are often found, on small hummocks 

 where cover of other herbaceous vegetation is 

 fairly high; these sites are also often at 

 least partially shaded by overhanging shrub 

 and tree species. Thus, it appears that, 

 within its own habitat, the species has some 

 tolerance for interspecific competition. 



b. HERBIVORY: Field observations during 1988 

 did not indicate that O. rotundifolia is 

 subject to heavy browsing by native 

 herbivores. However, the Green Timber Basin 

 (002) site is subject to livestock grazing 

 each summer beginning in early July, and the 

 area is moderately to heavily grazed. The 

 long-term effects of this activity should be 

 closely monitored, to determine population 

 trends. 



H. LAND OWNERSHIP 



1. The land ownership for the 17 occurrences 



currently known in Montana is given below. The 

 exact locations are provided in Table 1, pp. 5-8. 



a. U.S. FOREST SERVICE: 



i. Flathead National Forest, Spotted Bear 



Ranger District, Bob Marshall Wilderness 

 Area: 



Butcher Mountain Meadows (004) 

 White River (005) 



