«) I 



sandy-loam texture and are deep to moderately 

 deep. 



In the Yellowstone area soils supporting C. 

 longispica are poorly developed and gravelly with 

 a sandy texture. These soils are derived from 

 mixed sedimentary parent material. 



4. REGIONAL CLIMATE: Red Lodge (5,575 ft), at the 



north end of the Beartooth front had mean July and 

 January temperatures of 64.9° F and 21.8° F 

 respectively, and mean annual precipitation was 

 25.0 in. Wettest months were April, May and June 

 (NOAA 1982) . The town of Bridger is in the valley 

 of the Clark's Fork of the Yellowstone River at 

 3,680 ft, ca. halfway between the foothills of the 

 Pryor Mountains and the Beartooth front. Mean 

 July and January temperatures were 70.5° F and 

 21.5° F respectively, and mean annual 

 precipitation was 12.67 in (NOAA 1982). The 

 climate of the Castilleja longispica populations 

 is probably warmer and drier than Red Lodge but 

 cooler and wetter than Bridger. 



West Yellowstone, 6,600 ft. at the northwest edge 

 of Yellowstone National Park had mean July and 

 January temperatures of 60.1 and 11.7° F 

 respectively, and mean annual precipitation was 

 22.3 in. Wettest months were June, December and 

 January (NOAA 1982). 



5. DYNAMIC ABIOTIC FACTORS: Fire was undoubtedly an 



important dynamic force in the sagebrush-grassland 

 communities that support C. longispica. Before 

 the advent of fire suppression, dense stands Of 

 sagebrush were destroyed by fire on an average of 

 every 35-40 years (Arno and Gruell 1983) . 

 Castilleja longispica is almost always found 

 growing with big sagebrush (Hitchcock et al. 

 1959) , perhaps indicating that Artemisia 

 tridentata is the preferred host for this 

 hemiparasitic plant. In this case fire would 

 decrease the abundance of C. longispica as well as 



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