Skip to Main Content
Interference with shoot growth and flowering of dittany (Cunila origanoides (L.) Britton) by hardwood leachatesAuthor(s): J. W. Van Sambeek; Jane M. Kobe; James S. Fralish
Source: In: Pallardy, Stephen G.; Cecich, Robert A.; Garrett, H. Gene; Johnson, Paul S., eds. Proceedings of the 11th Central Hardwood Forest Conference; Gen. Tech. Rep. NC-188. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: 294-303
Publication Series: General Technical Report (GTR)
Station: North Central Research Station
PDF: View PDF (1.42 MB)
DescriptionThis study examined the potential role of hardwood leachates in the reduction of understory forbs in oak-hickory stands following invasion by sugar maple and dense-canopy shrubs. We conducted a shaded greenhouse experiment during two summers using stonemint dittany (Cunila origanoides (L.) Britton) as an indicator species. We used a modified stair-step bioassay with donor pots producing two levels of recycled leachates from hardwood seedlings root exudates, foliage washes, and decaying leaves. At the lower density, each donor pot had three hardwood seedlings and three applications 300 cm? of mature leaves of the same species to the litter layer (LAI = 1.5). At the higher density, we doubled the number of seedlings and surface area of mature leaves in the litter layer (LAI=3.0). Donor species tested for 1 or 2 years included sand-only, sugar maple, white oak, flowering dogwood, pawpaw, and black walnut. Dittany stem height ranged from 38 cm when exposed to leachates from white oak seedlings to 49 cm when exposed to leachates from sand-only donor pots. Dittany stem dry weights showed no differences in either year in response to leachates produced by different hardwood seedlings or at the two donor densities. Most dittany stems produced nearly 2,000 flowers during a 10 week period which began with completion of axillary shoot elongation. No differences in date of flower initiation or cumulative flower production were found in response to any of the hardwood leachates. We conclude that allelopathic interference of dittany by hardwoods, if it occurs at all, may require more stressful conditions than were created in this study and that the absence of dittany in oak-hickory stands after the invasion by sugar maple or pawpaw results primarily from competition for light and other resources.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationVan Sambeek, J. W.; Kobe, Jane M.; Fralish, James S. 1997. Interference with shoot growth and flowering of dittany (Cunila origanoides (L.) Britton) by hardwood leachates. In: Pallardy, Stephen G.; Cecich, Robert A.; Garrett, H. Gene; Johnson, Paul S., eds. Proceedings of the 11th Central Hardwood Forest Conference; Gen. Tech. Rep. NC-188. St. Paul, MN: U.S. Department of Agriculture, Forest Service, North Central Forest Experiment Station: 294-303
- Species composition changes under individual tree selection cutting in cove hardwoods
- Wisconsin's forests, 2004
- Stand compositional dynamics in a mature Illinois Ozarks forest: implications for management
XML: View XML