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From page 38... ... General Versus Species-Specific Control Methods The most successful invasive species control has been achieved with species-specific methods, which also have the least impact on nontarget species. In some instances, such as highly degraded habitats without any native species remaining, a more general method is acceptable. Read the entire page →
From page 39... ... Different Types of Biological Controls The aim of biological control is not to eradicate targets. In a successful biological control program, the invasive species' population will be reduced to an acceptable level, but populations of prey or host and natural enemies will remain present in a dynamic balance. Read the entire page →
From page 40... ... Such species would not be used today in biological control, and some of them are good examples of invasive alien species causing serious Read the entire page →
From page 41... ... Large-scale or mass releases of natural enemies are made to react quickly to control a pest population. Self-sustaining biological controls include: • Classical biological control, which at its simplest is the introduction of natural enemies from the original range of the target species into new areas where the pest is invasive. Read the entire page →
From page 42... ... Cornell's Invasive Plant website on Biological Control of Non-Indigenous Species is dedicated to promoting and educating people about the biological control of nonindigenous plant species and the site lists plant species where biological controls are available for eastern North America. The Global Invasive Species Programme suggests the following sites: • IPPC Code of Conduct for the Import and Release of Biological Control Agents (1996) Read the entire page →
From page 43... ... It does, however, give rise to the concern that the invasive species then becomes a valuable commodity that should be preserved to continue to generate this income. Furthermore, there are many instances where recreational hunting will not reduce the target population sufficiently. Read the entire page →
From page 44... ... • If invasive plant populations consist of large, mature plants, mow the plants before seed maturation, allow the plants to regrow to a height of 2 to 4 ft and then treat the area with foliar herbicide, especially in or adjacent to drainage ditches. • Physically remove flower or seed heads (cut and bag) Read the entire page →
From page 45... ... If the dominant vegetation has not yet shifted to invasive species and still contains adequate grass cover, mowing should generally be timed so the weeds are at the flowering stage and the grasses are dormant. When the dominant vegetation is a noxious weed, MDT recommends mowing 2 in. Read the entire page →
From page 46... ... Grasses were only decreased by the most aggressive mowing treatments. Integrating Mowing with Other Management Methods Although mowing will not eradicate invasive species, it can stress them, greatly reduce seed production, and help give native plants a competitive edge. Read the entire page →
From page 47... ... usually kills the plant, whereas cutting before flowering, although effective in preventing another seed crop, may result in resprouts and little mortality. Cleaning Mowing, Cutting, and Removal Equipment Equipment used for invasive species control, whether hand tools or power driven, should be cleaned before entering a new site and before leaving the site, to reduce transport of plant propagules and the potential for new invasive introductions. Read the entire page →
From page 48... ... Controlled Burns Eight percent of DOTs are using controlled burns to restrict invasive species and foster native revegetation. Controlled burning or prescribed fire is a carefully planned and controlled fire conducted to manage natural areas such as prairie, oak savanna, wetlands, and oak woodlands. Read the entire page →
From page 49... ... More detailed information on controlled burns for invasive species management may be found in the Center for Invasive Plant Management's on-line resource: "Fire as a Tool for Controlling Non-Native Invasive Plants" (90) Read the entire page →
From page 50... ... Hence, litter removal by haying will likely be a sufficient practice to replace prescribed burning at many sites. Department of Transportation Examples of Controlled Burning for Invasive Species Management A number of midwestern state DOTs use controlled burns. Read the entire page →
From page 51... ... . In 2000, a Billings Public Utilities Department maintenance mechanic hired a pair of angora goats to munch on a particularly abundant yellow-flowered noxious weed that grows along the banks of the Yellowstone River. Read the entire page →
From page 52... ... Many other invasive species can be eaten or have edible fruits, which can be exploited for human consumption or as fodder for domesticated animals. In many parts of the world with high human density, invasive plants are also esteemed for their production of highly valued firewood or for other uses. Read the entire page →
From page 53... ... IVM stresses the need for selectivity, restraint, and proper training and protections whenever herbicides must be used. On the road shoulder and in other zones too, invasive species must be controlled to protect against the undesirable succession of plant communities, not only for the sake of the roadside zone itself, but also to prevent the roadside from becoming a refuge for invasive species and the source of further spreading. Read the entire page →
From page 54... ... • Prescribing burning of prairie communities to promote healthy vegetation. • Using biological controls as alternatives. Read the entire page →
From page 55... ... In dealing with the most sensitive and controversial areas to date, WSDOT's IRVM approach has incorporated the following: • Planning -- development of an IRVM plan that contains an inventory of roadside management features and provides specific documentation on how WSDOT will treat various aspects of the roadside. • Communications -- meetings and ongoing dialogue with interested individuals, groups, local governments, tribes, and neighboring landowners to discuss, negotiate, and decide on specific roadside vegetation management policy and practice. Read the entire page →
From page 56... ... Many agencies are using native grasses to control invasive species, because their dense, deep root systems inhibit weed growth. Both Minnesota and Iowa DOTs have found success in controlling invasive species and Canada thistle, in particular in Minnesota, using native grass stands (72) Read the entire page →
From page 57... ... Protected species are identified and restricted maintenance practices are incorporated to protect the endangered species; construction practices are also altered to minimize disturbances of native plant communities whenever possible. In several states, special vegetation management programs have been developed to protect Karner Blue Butterfly habitat, including mowing date restrictions and native blue lupine and butterfly weed restoration planting and seeding. Read the entire page →
From page 58... ... WSDOT discovered the following through the agency's value engineering work: • Some of the biggest problems in relation to roadside vegetation management and invasive species control stem from inadequate consideration of soil conditions, restoration of desirable roadside vegetation, and weed control in design and construction. • Through the value engineering study, WSDOT identified a series of recommendations that, if implemented, could result in improved weed control and reduced herbicide use over the long term; in effect, reducing the roadside maintenance requirements over the life cycle of the highway. Read the entire page →
From page 59... ... • Plan for seed collection and plant salvage if native remnants will be disturbed by the project. Department of Transportation Revegetation Practices -- Survey Results As part of their commitments to reduce invasive species and to develop attractive and sustainable roadside environments that are better for native species and agency budgets, many DOTs are turning to native revegetation projects and plans. Read the entire page →
From page 60... ... . Policies or Plans Specifying Native Revegetation Policies or plans specifying native revegetation are already in place in 17 states (43% of responding DOTs) Read the entire page →
From page 61... ... It is more common for custom mixes to be developed on capital projects; maintenance forces more often draw on standard seed mixes. Mn/DOT, PennDOT, and other DOTs have designed and specified special seed mixes for areas outside of the standard highway construction slopes, including wetlands, wildlife habitat, and streambank mitigation. Read the entire page →
From page 62... ... DOT vegetation management personnel also identified the following as problematic: • Intense invasive seedbanks in some cases adjacent to the ROW. • Contract language for establishment of native grass within contract because the work required is dynamic and changing with the seasons; that is, "adaptive management." • Weed control during establishment period requires a greater investment than field maintenance resources can provide. Read the entire page →
From page 63... ... Thirty-eight percent of responding DOTs reported that they do not rely on native grasses and forbs in erosion control, landscaping, and revegetation. For example, PennDOT noted that "native plants are not always the best plant for the roadside environment." However, many of those DOTs that do not necessarily rely on the use of native species report that their use is increasing, new internal resources are being developed, and native seed sources are being located. Read the entire page →
From page 64... ... non-native grass seed mixes. Iowa Department of Transportation Revegetation Program Controls Invasive Species Although many state DOTs have begun to mandate the use of native species when revegetating construction sites, Iowa DOT has extended their landmark IRVM program to annually revegetate approximately 2,200 acres of targeted roadside areas not connected to any construction projects. Read the entire page →
From page 65... ... -- CT, IL, IA, MN, MS, NH, NC, NY, OH, RI. • Native seed mixes use native grass and forb species (9 DOTs, 23%) Read the entire page →
From page 66... ... • NCDOT Vegetation Management Maintenance Program. • Oregon 2005 Noxious Weed Policy and Classification System. Read the entire page →

From page 38...

... General Versus Species-Specific Control Methods The most successful invasive species control has been achieved with species-specific methods, which also have the least impact on nontarget species. In some instances, such as highly degraded habitats without any native species remaining, a more general method is acceptable.