The Highlands Least Wanted
Invasive plants are common throughout the Northeast and are spreading from disturbed areas into native vegetation. Although nearly one-third of the current Massachusetts flora is not native to the state, only a small subset of these species (less than 10%) are considered invasive and are having detrimental impacts on the ecological and, in some cases, agricultural, scenic, and recreational resources of our landscapes.
These invasives include herbs, shrubs, trees, and vines that grow rapidly, form dense thickets, and negatively impact native species and natural communities. Non-native invasives, such as Asian honeysuckles, Japanese barberry, autumn olive, burning bush, multiflora rose, garlic mustard, and glossy buckthorn, are considered by the Massachusetts Department of Agricultural Resources, New England Wildflower Society, U.S. Forest Service and others as some of the worst invaders in the region.
In addition to the many ecological issues associated with invasive species, these plants can also degrade the scenic qualities of our natural landscapes (e.g., bittersweet choking a hedgerow of native trees), alter an otherwise intact cultural feature (e.g., goutweed taking over a formal garden), and impair agricultural activities (e.g., multiflora rose dominating a pasture, buckthorn spreading in a hayfield).
Why manage invasive plants?
- Preservation of biodiversity. The loss of biodiversity is an issue of global concern. Management that protects and encourages native species, communities, and ecological processes will help maintain the biodiversity of Massachusetts. Non-native invasive plants may reduce native species diversity through direct competition. Similarly, invasive species may alter habitats and thereby impact native wildlife species.
- Preservation of cultural resources, including designed gardens and landscapes, and agricultural and forest productivity. Designed landscapes require continual maintenance, often including the removal of non-native invasive “weeds.” Invasive species are also impacting the success of agricultural programs by degrading the quality of the product (e.g., hay), reducing the productivity of an area, and draining resources away from production. Examples include multiflora rose invading pastures and thereby reducing the forage available; buckthorn, bittersweet, and other woody species invading hayfields; and knotweed establishing in compost piles, thereby threatening to spread elsewhere as the compost is applied. In some instances, thick infestations of invasive shrubs have prevented seedling establishment of desirable tree species.
Prevention: The first line of defense for invasive species is prevention. The most cost-effective and complete approach to combating invasive species is to keep them from becoming established in the first place.
- Use fill that is clean of invasive species seeds or propagules.
- Clean equipment before transporting it between properties or habitats, especially when used in areas with known invasive species.
- Do not plant or propagate known or potential* invasive species. Review the MA Department of Agricultural Resources’ prohibited species list.
- Monitor new plantings, whether within designed landscapes, farms, or elsewhere, for invasives that may have been present in soils.
- Work with neighbors to encourage these practices on abutting or neighboring parcels.
* Species that are currently known invasives in areas south of New England may migrate north as a result of climate change. As a preventative measure, the planting of these species should be avoided.
Links for more information on non-native invasive plants
Weeds Gone Wild: Alien Plant Invaders of Natural Areas is a web-based project of the Plant Conservation Alliance's Alien Plant Working Group. This link connects to their series of invasive plant fact sheets. Other information on the general website includes a national list of invasive plants infesting natural areas throughout the U.S., background information on the problem of invasive species, and selected links to relevant people and organizations.
Invasive Plant Atlas of New England. The atlas is a comprehensive web-accessible database of invasive and potentially invasive plants in New England. The database is continually updated by a network of professionals and trained volunteers. It details basic information on a large number of species including keys to identification, distribution in NE (with online maps), and their impact on native systems. An important focus of the project is the early detection of, and rapid response to, new invasions.
http://na.fs.fed.us/fhp/invasive_plants/weeds/index.shtm - These fact sheets from the USDA Forest Service Northeastern Area Forest Health Protection program include information about specific invasive plants that exist in the Northeastern United States.
http://tncweeds.ucdavis.edu/esadocs.html - Information from The Nature Conservancy on specific invasive plants. Other general information on invasive species management as well as invasive insects and animals can also be found at The Conservancy’s Global Invasive Species Initiative website (tncweeds.ucdavis.edu).
http://maccweb.org/resources_invasive.html - Invasive plant information and resources for Massachusetts Conservation Commissions. This site includes good general information on invasive species, links to other resources, and identification guides.
http://www.dnr.state.wi.us/invasives/publications/books.htm - Wisconsin Department of Natural Resources publications. They have a series of very good pamphlets on a variety of invasive plant species, including great information on control methods.
http://www.invasive.org/eastern/ - Invasive Plants of the Eastern United States: Identification and Control. This site is an online version of the booklet of the same name. It includes good photos of the invasive plants as well as links to many invasive plant websites.
Contact leastwanted@ttor.org for more information.