ROLE OF ALLELOPATHY IN HAY-SCENTED FERN INTERFERENCE WITH BLACK-CHERRY REGENERATION

Black cherry (Prunus serotina Ehrh.) seedlings survive and grow poorly under dense hay-scented fem (Dennstaedtia punctilobula Michx.) ground cover in the understory of partially cut Allegheny hardwood stands. Previous field studies showed that there were about 80% fewer black cherry seedlings where fem was present than where it was absent. Allelopathic interference with black cherry seed germination, seedling survival, and growth by hay-scented fem foliage leachates, root washings, and soil transformation products was evaluated in a series of field, greenhouse, and laboratory experiments. Black cherry seeds germinated as well in the presence of hay-scented fem or its leachates as when they were absent in both the laboratory and the field. Fem foliage leachates and root washings did not affect black cherry growth in sand or natural soil cores in the greenhouse. There also was no evidence that hay-scented fem natural products or their soil transformation products built up in the soil. A two-year manipulative field experiment to separate effects of hay-scented fem foliage shade from foliar leaching showed that foliage shade significantly reduced black cherry seedling survival and growth; foliage leachates had no effect. Results of the studies led to the conclusion that allelopathy does not play a direct role in hay-scented fem interference with black cherry seedling establishment in partially cut Allegheny hardwood stands.