17 



3. SOIL RELATIONSHIPS: Madia minima was found in 

 areas with less dense vegetation, and it is 

 possible that it requires bare soil for seedling 

 establishment. In north central Washington, Madia 

 glomerata populations are also found in bare 

 soils, which were found to be low in available 

 nitrogen, sulphur and phosphorus. It is possible 

 that these soil characteristics are limiting the 

 distribution of this species. It is more likely 

 that M. glomerata also requires bare soils for 

 seedling establishment, and has merely adapted to 

 the lowered nutrient availability at these sites 

 (Tiedmann 1972) . 



4. REGIONAL CLIMATE: The mountainous region of 

 northwestern Montana is dominated by a cool 

 Pacific temperate climate. The winters are cold 

 and snowy, and the summers are warm and rainy. 

 The highest amounts of precipitation accumulate 

 during the period from November through January in 

 the form of snow. The weather collection site at 

 Trout Creek Ranger Station is approximately 15 

 miles east of the Bull River valley, and at an 

 elevation of 2,370 feet (the M. minima sites are 

 at 3,000 to 3,600 feet in elevation). For the 

 period from 1951-1980, the July mean temperature 

 at Trout Creek Ranger Station was 65.0° F, the 

 January mean was 24.1° F, and the mean annual 

 precipitation was 30.49 inches (U.S. Department of 

 Commerce 1982) . 



F. POPULATION DEMOGRAPHY AND BIOLOGY 



1. PHENOLOGY: Depending on the latitude, elevation 

 and aspect of M. minima pbpulations, individuals 

 flower and fruit from May through July (Hitchcock 

 et al. 1955-1969) . In the Bull River valley this 

 species is flowering and fruiting from mid-June 

 through early July (pers. obs.). 



2. POPULATION SIZE AND CONDITION: Madia minima 

 populations in the Bull River valley were 

 generally quite large, ranging from 400 to 10,000 

 individuals. The populations appeared to be in 

 good condition and were fruiting prolifically in 

 1989. 



