Ferguson, Dennis E.; Boyd, Raymond J. 1988. Bracken fern inhibition of conifer 

 regeneration in northern Idaho. Res. Pap. INT-388. Ogden, UT: U.S. Department of 

 Agriculture, Forest Service, Intermountain Research Station. ii p. 



Investigations on the allelopathic potential of bracken fern in northern Idaho were 

 conducted to gain an understanding of the mechanism(s) associated with regeneration 

 failures. Average growth and green top weight of conifers planted in potting soil were 

 about 1 .8 and 1 .6 times greater than those planted in soil from bracken glades. 

 Greenhouse tests showed little reduction in germination of conifer and shrub seeds on 

 soil from bracken glades. Further germination tests of conifer seeds in bracken glades 

 showed that seeds germinated but died before shedding their seedcoats. The percent- 

 age of dead seed helps explain the virtual exclusion of conifers from bracken fern 

 glades in northern Idaho. 



KEYWORDS: Pteridium aquilinum, allelopathy, phytotoxins, competition 



