THE AUTHORS 



RESEARCH SUMMARY 



ROY 0. HARNISS is a range scientist at the Forestry 

 Sciences Laboratory, Logan, UT. He has conducted 

 ecological research in sagebrush and aspen vegeta- 

 tion. He has a B.S. degree from Washington State 

 University, Pullman, and an M.S. degree from Utah 

 State University, Logan. 



DALE L. BARTOS is an operations research analyst 

 with the Intermountain Station, Ogden. UT. For 13 

 years (1972-84) he was a range scientist associated 

 with the aspen ecosystem project at Logan, UT. Bartos 

 holds B.S. and M.S. degrees from Fort Hays Kansas 

 State University, and a Ph.D. degree in range science 

 from Colorado State University. His principal research 

 interests are systems modeling and ecological 

 research. 



Aspen stands sprayed with herbicide were compared 

 to aspen stands not sprayed in the Western United 

 States. The herbicide 2,4-D mixed at about 2 lb/acre 

 (2.2 kg/ha) with water or diesel was most commonly 

 used. Average number of live aspen trees over 

 2 inches (5 cm) diameter; stand height, age, and 

 diameter; basal area; and disease incidence were 

 higher in the unsprayed stands. Average number of 

 suckers was generally higher in the sprayed stands. 

 The exception to sufficient suckering occurred where 

 small isolated aspen clones were heavily grazed. There 

 were more grass species and fewer forb species in the 

 understory of the sprayed stands. Grass and total 

 vegetation production was also higher in the sprayed 

 stands. Vegetative cover was greater in the sprayed 

 stands, but organic matter was deeper on the 

 unsprayed plots. 



PESTICIDE PRECAUTIONARY STATEMENT 



This publication reports research involving pesticides. It 

 does not contain recommendations for their use, nor 

 does it imply that the uses discussed here have been 

 registered. All uses of pesticides must be registered by 

 appropriate State and/or Federal agencies before they 

 can be recommended. 



CAUTION: Pesticides can be injurious to humans, 

 domestic animals, desirable plants, and fish or other 

 wildlife— if they are not handled or applied properly. 

 Use all pesticides selectively and carefully. Follow 

 recommended practices for the disposal of surplus 

 pesticides and pesticide containers. - 



FOLLOW TUB LABEL 



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The use of trade, firm, or corporation names in this 

 publication is for the information and convenience of 

 the reader. Such use does not constitute an official 

 endorsement or approval by the U.S. Department of 

 Agriculture of any product or service to the exclusion, 

 of others that may be suitable. 



