Table 12. Stipa viridul j - Agropyron ^mi thi 1/Doiite loua gracilis Connunity Type Site Description 



SOIL texture: 



23% louins; 46" silt loams; 23= silty clay loams; 8% clay loams 



SLOPE-SLOPE ASPECT 



Mean: 



Standard deviation: 



Range : 



Sites naving: 



Positive slope-slope aspect values: 

 Slope-slope aspect values of 0: 



The Stvi-Agsm/Bogr c.t. are often found in coulees and depressions where 

 the moisture regime is well above average. With this extra moisture, Stipa 

 viridula can apparently withstand grazing fairly well. 



Soils for this type are not the dense clayey range soils often associated 

 with S^. viridula (j^hite and Lewis, 1969), nor are they necessarily vertisols. 

 Indeed, in some coulees Andropogon scoparius can be found in close proximity 

 to S. viridula, although this does not imply that the substrates are identical. 



In comparison to Agsm/Bogr c.t. sites, these sites are moister, have a 

 somewhat heavier soil and are not grazed as heavily. 



46 



