12 



2. Air and water quality requirements: N/A 



3. Physiographic province: Northern Rocky 

 Mountains (Fenneman 1931) 



4. Physiographic and topographic characteristics: 



Eriqeron lackschewitzii was most frequently 

 found on exposed alpine slopes having southwest 

 aspect. Many of the sites are at or near 

 topographic features which break wind velocity, 

 including saddles, protruding outcrops, and 

 crests of updraft chutes. The majority of 

 sites lie along a single divide between the Sun 

 River and Teton River drainages. 



It grows on midslope settings often between 

 scree and toeslope turf, or on gentle but 

 highly exposed slope crests and ridgelines. 

 This microtopography is limited within the 

 Front Range, and was wanting at the sites of 

 unsuccessful searches conducted in the course 

 of this project- 

 In addition to the typical settings of the 

 large, south-facing alpine population sites, 

 there are also small northwest-facing 

 populations at both alpine and subalpine 

 elevations. The elevations range from 6400- 

 8200 feet, the low sites located in exposed 

 settings at the east edge of the Front Range. 



5. Edaphic factors: Eriqeron lackschewitzii is 

 found exclusively on calcareous soil derived 

 from dolomite, the overriding factor 

 circumscribing its potential habitat in the 

 Front Range. Soils are cryptorthents of 

 gravelly silt or loam, varing in their degree 

 of organic matter and in their surface cover. 

 Typical cover has almost 50% cobble and pebble 

 rock fragments, though the range of rock cover 

 ranges from 5-95%. While these soils are 

 relatively thin, water loss is impeded by 

 surface rock cover, and water retention in 

 limestone-derived soils is higher than that of 

 soils from many other parent materials. 



6. Dependence of this taxon on natural 

 disturbance: There was no apparent correlation 

 with alpine disturbance processes like 

 solifluction and frost heaving. 



7. Other unusual physical features: N/A 



