Lonicera japonica - allelopathic effects on pine regeneration
In reference to Jil's note: "In case you'd given up on trying to
manage Japanese honeysuckle, here's some information that
may rekindle your interest in targeting this plant." I would like
to share our experiences.
We pull out Japanese honeysuckle by the roots in Winter in the
forested areas wherever we see it up in the trees, aim the roots
upward and tie them in place. The absence of light energy causes
the trailing vines to decline precipitously the next year. Thus
we control 80% of the honeysuckle with 10% of the effort to
control all of it and minimal soil disturbance.
Do not pull it out of the trees and watch for native vines
(moonseed, trumpet vine, native grape etc.). This method
greatly reduces spraying requirements.
Removing the horizontal component may require the use of
herbicide in Winter or late Fall to avoid natives.
The status at the 200 acre Swann Park is 80 percent cleared totally
and 95% cleared of the vertical component. The status at Chapman
Forest is 500 acres cleared of the vertical component.
None have come back up the trees even 5 years after removal.
Marc Imlay, PhD
Chair of the Biodiversity and Habitat Stewardship Committee
for the Maryland Chapter of the Sierra Club.
Board member of the Mid-Atlantic Exotic Pest Plant Council,
Hui o Laka at Kokee State Park, Hawaii
Vice president of the Maryland Native Plant Society,
Conservation biologist, Anacostia Watershed
Society (301-699-6204, 301-283-0808)
JIL M SWEARINGEN
Invasive Species and
Pest Management Coordinator
NATIONAL PARK SERVICE
National Capital Region
Center for Urban Ecology
4598 MacArthur Blvd., NW
Washington DC 20007
Phone/ 202-342-1443, ex. 218
The attached article was sent to me by Dan Kjar, the G'tn. grad. student
who is putting together the invertebrte database for the region. It's a
little scary to think that the leaf litter of Japanese honeysuckle may be
allelopathic. The research only tested it on pines, but...
(See attached file: skulman2004.pdf)
Resource Management Specialist - Vegetation
Rock Creek Park