Differences occurred between the sprayed and 

 unsprayed stands in the direction to be expected 

 (table 2). Average number of live trees over 2 inches 

 (5 cm) d.b.h., stand height, stand age. stand diameter, 

 basal area, and disease incidence were higher in the 

 unsprayed stands. Average number of suckers was 

 generally higher in the sprayed stands, especially in the 

 over 6.5-ft (2-m) category. The larger variation evident in 

 the sprayed data is due partly to the variation in the 

 number of years since spraying. The range in the 



number of live trees and stand attributes for the 

 unsprayed stands is about the expected range for aspen 

 forests in the West (Baker 1925; Mueggler and Campbell 

 1982). However, average stand height, diameter, and 

 basal area appear low for aspen. Perhaps most of the 

 aspen stands associated with sagebrush spraying had 

 drier site condition or poorer stand quality. Suckering on 

 all sprayed stands was generally sufficient for rejuvenat- 

 ing the stand (fig. 3). The exception to sufficient sucker- 

 ing occurred in areas where the aspen clone was small 



Table 2.— Tree and stand attributes for 34 sprayed and 22 unsprayed aspen stands 



Sprayed Unsprayed Range 



Variable Units x ± s 1 x ± s t Prob Sprayed Unsprayed 



Trees 



Live >5 cm 



no/0.01 



ha 2 



12.1 ±13.0 



21.0+10.3 



0.0046 



0-53 



9-50 



Dead >5 cm 



no/0.01 



ha 



9.0 ±9.9 



6.7 ±4.3 



.1608 



0-42 



1-16 



Stumps 



no/0.01 



ha 



14.5±9.5 



3.1 ±4.2 



.0000 



0-33 



0-14 



jckers 

















Live <0.5 m 



no/0.01 



ha 



32.4 X 59.4 



16.5 + 19.0 



.1155 



0-212 



0-80 



Dead <0.5 m 



no/0.01 



ha 



4.0 + 14.0 



1.0 ±2.5 



.1632 



0-80 



0-11 



Live 0.5-2 m 



no/0.01 



ha 



54.8x99.4 



23.0 ±28.9 



.0753 



0-548 



0-121 



Dead 0.5-2 m 



no/0.01 



ha 



11.0 ±11.7 



4.9±8.3 



.0200 



0-37 



0-34 



Live >2 m-5 cm d.b.h. 



no/0.01 



ha 



39.9±45.1 



5.2+12.3 



.0005 



0-131 



0-57 



Dead >2 m-5 cm d.b.h. 



no/0.01 



ha 



6.3 ±9.6 



2.1 ±2.6 



.0233 



0-42 



0-8 



:ands 

















Height 



m 





8.7 ±5.7 



12.6±3.4 



.0010 



0-20 



6-20 



Age 



years 





47.7±39.4 



83.7x21.8 



.0001 



0-129 



38-117 



Average d.b.h. 



cm 





7.9±5.6 



15.0x3.3 



.0000 



0-19.6 



8.4-20.8 



Basal area 



m 2 /0.01 



ha 



0.102 + 0.115 



0.368±0.161 



.0000 



0-0.4366 



0.1208-0.7399 



Disease 



P/A 3 





0.029±0.172 



0.318 ±0.477 



.0010 



0-1 



0-1 



'Average ± standard deviation. 



2 Multiply by 100 for numbers/hectare; 40.47 for numbers/acre. 

 3 Presence or absence. 



Figure 3. — Abundant regeneration of aspen 

 3 years after herbicide spraying. 



4 



