Control of Exotic and Invasive Species
Exotic and invasive plants are one of the greatest threats to the Franklin Park environment, and if left unchecked, its diverse landscape will be overtaken by exotic and invasive species. These plants crowd out native species and eliminate wildlife habitat. Their dense stands impact public safety by diminishing sight lines and creating potential hiding spaces.
In their home geographic regions, environmental conditions, such as climate and natural predators keep exotic species in check. In New England, landscape and forestry managers must intervene to limit their spread. The goal is to achieve a level of ongoing control in which they do not threaten the beauty, sustainability, wildlife, and public safety as they currently do throughout the park.
How has FPC tried to remove and control invasives?
For the last five years the Franklin Park Coalition has involved volunteers, many of them youth, in an intensive removal program. About 1,000 people annually contributing thousands of hours, have cut Japanese knotweed, the most intractable invasive, and pulled glossy buckthorn trees by their roots. When we first began this work the emerging research said that repeated cutting of Japanese knotweed would eventually kill the plant by deterring photosynthesis. Knotweed cannot be pulled by the root as bits left in the ground regenerate and help spread the plant. Roots can be 30 feet long and run underneath paved roadways to spread the plant to the other side.
Volunteers have repeatedly cut several large stands of knotweed through the late spring, summer and fall growing season for 4-5 consecutive years. We may have slowed its spread and retarded its growth, but it still returns every spring hardier than ever and is spreading throughout the park. We know from first hand experience that this strategy will not save the woodlands from being overrun by knotweed. Current research shows that the only way to effectively remove a stand of Japanese knotweed is to use a low-level herbicide.
Who will perform the work, and where?The Franklin Park Coalition and the Boston Parks Department are working in partnership on a demonstration project. In order to control exotic and invasive species, we will employ manual removal, and where necessary herbicide application by a licensed herbicide applicator. Long Crouch Woods is the 13-acre demonstration area where we are testing components of a draft Woodlands Management Plan. The four most intractable, prominent and quick-spreading exotic and/or invasives – those that pose an immediate threat to the park’s ecology and public safety – are targeted for treatment. Attached is a map, displaying the targeted areas.
Methods- Japanese Knotweed – stem injection of 5cc glyphosate into each stalk
- Glossy Buckthorn – Where trees cannot be removed manually (e.g. growing in rock outcrops), trees will be cut down and stumps will be painted with glyphosate mix, triclopyr mix or apply a triclopyr/mineral oil mix to base of bark.
- Oriental Bittersweet – Where vines cannot be removed manually, they will be cut and painted with glyphosate or triclopyr
- Poison Ivy - Spray on leaves using 4% solution of glyphosate, carefully controlling droplet size to prevent runoff and only spraying when wind speeds are less than 10 mph.
- Continue to do manual removal and control wherever possible
- Ensure public safety by reducing stands of invasives near public areas
- Protect threatened specimen trees and shrubs
- Control invasions of otherwise pristine areas
- Preserve important views
- Control invasions deeper in the woods
- Areas to be manually treated or treated with herbicides will receive laminated signs explaining the process that is to take place. This will occur 48 hours before any work.
- Areas where herbicides will be used within 20 feet of a walkway or public area will be roped or fenced off prior to application.
- Signs and barrier will remain in place for a full week after application.
The Department of Environmental Health at the B.U. School of Public Health is partnering with the Franklin Park Coalition to evaluate herbicide use and its impact on the park environments. Under the direction of Professor Wendy Heiger-Bernays, a toxicologist and expert in herbicide use world-wide, students will test soils and surfaces before, just after, and at determined periods following herbicide application. With their assistance, FPC has gathered the most recent science and literature around herbicide use in public parks and conservation lands to control invasives. The environmental health team is available to address public health concerns, answer questions, and discuss issues with park users. FPC came to the decision to use herbicides reluctantly, but are thrilled to be working with the B.U. group. We expect the research and data gathered will inform future decisions about herbicide use.