I.6.C.1 



14 



Shelly, 1988) . This report details the 

 possible influence of soil crust on this 

 species. 



Vegetation, physiognomy and community 

 structure: Sites in the Pioneer Mountain 

 drainages are often under a very sparse 

 overstory of Juniperus scopulorum (Rocky 

 Mountain juniper) , Pseudotsuqa menziesii 

 (Douglas fir) and Pinus ponderosa (ponderosa 

 pine) . The dominant shrubs are 

 Cercocarpus ledifolius (curly-leaf mountain 

 mahogany) or Artemisia tridentata (big 

 sagebrush) . The associated species at the 

 new site in the foothills of the Sapphire 

 Range, Birch Creek Bluffs (004), are similar 

 to those previously reported from that area. 



I.6.C.6. Dependence on dynamic aspects of biotic 



associations and ecosystem features: Arabis 

 fecunda may be influenced by the presence and 

 abundance of Centaurea maculosa (spotted 

 knapweed) at the sites along the eastern edge 

 of the Sapphire Mountains. A report on 

 detailed studies of these effects is included 

 in Appendix B, p. 36 (Lesica and Shelly, 

 1988) . 



1-7. A. GENERAL SUMMARY: Additional subpopulations 



and/or numbers of plants were recorded for 

 the three sites in the original report. 

 Charleys Gulch (001) now includes thirteen 

 subpopulations and contains approximately 

 8,000-10,000 plants. Spring Gulch (002) now 

 includes four subpopulations containing 

 approximately 1,000-1,500 plants. Rock 

 Quarry Gulch (003) still consists of only one 

 population, but additional plants were 

 recorded for this site, bringing the total 

 number to approximately 800-1,000. The new 

 Birch Creek Bluffs (004) population has six 

 subpopulations, with approximately 10,000+ 

 plants, within a radius of 3/4 mile. 



Populations and subpopulations in the Pioneer 

 Mountain drainages consist of from 75-10,000 

 plants. These populations are within a 

 radius of ca. 16 miles of one another. The 

 largest distance separating all known 

 populations is ca . 95 miles (between the Lime 

 Gulch (012) site in the Pioneer Mountains, 

 and the Sapphire Mountain populations) . 



