Rice, Peter M.; Bedunah, Donald J.; Carlson, Clinton E. 1992. Plant community diversity 

 after herbicide control of spotted knapweed. Res. Pap. INT-460. Ogden, UT: U.S. 

 Department of Agriculture, Forest Service, Intermountain Research Station. 6 p. 



Herbicides were applied to four west-central Montana sites with light to moderate 

 spotted knapweed (Centaurea maculosa Lam.) infestations. Although knapweed suppres- 

 sion was high, 2 years after the spraying the communities were not converted to grass 

 monocultures. No large declines in plant diversity were caused by the herbicides, and 

 small depressions were probably transitory. By the third year, diversity had increased. 



KEYWORDS: Centaurea maculosa, leaching, native plants, soil residues 



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. 



<rU.S. GOVERNMENT PRINTING OFFICE: 1992-774-041/61020 



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