Site quality tias not been taken into account in using these equations. 



The Department of State Lands requested some quantitive description of the 

 shrub dominant of this community type. The Shar/Syoc-Rosa c.t. exhibits a good 

 deal of variability with respect to site and floristic composition. Two samples 

 of the Shar/Syoc-Rosa c.t. were taken on very different sites. The first sam- 

 ple was taken at the head of a coulee finger on a north aspect. The coulee 

 there was shallow and not steep banked, and affording S^. argentea little pro- 

 tection or extra moisture relative to the typical Shar/Syoc-Rosa c.t. site. 

 Mery little snowberry and rose were present on this dry site. 



The second sample was taken in a steep banked coulee about 20 feet deep 

 which afforded excellent protection and received above average moisture. A 

 few small cottonwoods near the sample site suggest an excellent soil moisture 

 regime. This sample also contained some P^. virginiana . 



Because it is exceedingly well armed, S^. argentea is a different shrub to 

 work around. Height was measured to the nearest decimeter. Crown area was 

 estimated by measuring live crown width at the widest point and normal to 

 that line. Basal diameter was measured as low as possible, usually a few 

 centimeters above ground. If a major portion of the plant was dead, diameter 

 was measured above the fork where the dead trunk split from the live one. 



Table 42 Dimensions of Some Shrubs 



Diameter (cm.) Height (m) 



Species X S X" S 



Sample 1 Shar 10.3 3.9 2.4 0.6 



Sample 2 Shar 5.6 1.3 2.2 0.4 



Prvi 2.1 0.4 1.8 0.4 



Estimated leaf weight for P. virginiana is 35. 4g (S=13.3g) and estimated 

 above ground weight is 275. 4g TS=148r8g). 



In S. argentea, diameter and crown area are linearly correlated, but not 

 strongly. In Sample 1, the correlation is significant at the five percent 

 probability level and r2 = .32. In Sample 2, the correlation is significant 

 at the 1% probability level and r^ = .44. Diameter was correlated with height 

 in the Sample 1 at the five percent probability level (r = .34), but in Sam- 

 ple 2, diameter and height were negatively correlated, but not significantly 

 so. Height and area were not well correlated. 



Somewfiat better correlations exist for P. virginiana . Diameter and crown 

 ai^ea are significantly correlated at the five percent probability level and 

 r^ = .48. Diameter and height are also significantly correlated at the five 

 percent probability level and r^ = .46. 



73 



