The Northeastern Area Invasive Forest Plant Species Project Guide to the Invasive Plant Control Demonstration Plots

Transcription

1 The Northeastern Area Invasive Forest Plant Species Project Guide to the Invasive Plant Control Demonstration Plots Prepared by: Ellsworth Land Management, LLC Somerville, MA

2 Table of Contents Project Overview... 2 Invasive Plant Ecology... 2 Plant traits... 2 Disturbance history... 3 Planning Control and Restoration... 4 Define Objectives and Assess Resources... 4 Prioritizing Sites... 5 Who will do the Work: Volunteers or Professionals?... 5 Control Methods... 6 Mechanical... 6 Herbicides... 7 Application methods... 7 Foliar spray... 8 Cut-stump... 8 Basal spray... 9 Reducing non-target kill... 9 Restoration/Replanting Guide to Demonstration Plots Site #1: Asiatic bittersweet control site Site #2: Honeysuckle control site Site #3: Glossy buckthorn control site Site #4: Japanese barberry control site Common Invasive Species in New England Forests Asiatic bittersweet (Celastrus orbiculatus) Japanese barberry (Berberis thunbergii) Shrub honeysuckcle (Lonicera spp.) Winged euonymus/burning bush (Euonymus alata) Japanese knotweed (Polygonum cuspidatum) Multiflora rose (Rosa multiflora) Autumn olive (Eleaganus umbellata) Common barberry (Berberis vulgaris) Glossy buckthorn (Frangula alnus) Common buckthorn (Rhamnus cathartica) Garlic mustard (Alliaria petiolata) Additional Resources Pesticide Laws Pesticide Labels...Error! Bookmark not defined. Plant Facts/Identification Tools...Error! Bookmark not defined. 1

3 Project Overview Non-native, invasive plant species have become common in many of New England s forests. Invasive species can out-compete native plants for nutrients, water, light, and germination sites and often become the dominant vegetation type, threatening the regeneration of native species important for wildlife habitat, biodiversity, and timber production. As a result, the successful, long-term management of New England s forests will increasingly depend on the ability of land managers to develop and implement techniques and strategies to control invasive species populations and restore native plant communities. The Northeastern Area Invasive Forest Plant Species Project (NEA Invasive Project) was developed with funding from the USDA Forest Service, State and Private Forestry to provide land managers with a working knowledge of invasive plant ecology and strategies for control. This booklet provides an overview of invasive plant ecology, traits, and general control strategies, and serves as a guide to the NEA Invasive Project s demonstration control plots. The plots were designed to incorporate several invasive plant species often found in New England s forests and to showcase some commonly used control methods. Photographs and written documentation of methods, labor, and materials are provided to help attendees understand the scope and costs of the work involved. Demonstration plots were also mapped and photographed at permanent photo plots to help evaluate the long-term response to treatment, and to facilitate the use of the demonstration plots for future workshops. The plots were designed in the spring of 2005 and control was implemented during the summer of The project was planned and managed through collaboration between the USDA Forest Service, State and Private Forestry, the Vermont Department of Forests, Parks and Recreation, including the Office of the Windham County Forester, the Windham County Natural Resources Conservation District, and Ellsworth Land Management, LLC of Somerville, Massachusetts. The project managers wish to acknowledge the landowners who have kindly allowed access to their land. Invasive Plant Ecology When planning the prevention and control of plant invasions it is important to consider that the success of invasive plants is often the result of multiple, interacting factors, most important, the invasive plants traits and a site s history of ecological disturbance. This is analogous to how foresters consider the growth traits and ecological requirements, or silvics, of timber species when planning regeneration cuts. However, the study of invasive plant ecology is a relatively new and rapidly evolving field, and knowledge of the plants traits are incomplete. Therefore, land managers should expect that new information on traits and control strategies may be emerging in the coming years. Plant traits The reasons behind the relative success of invasive plants over native species are not well understood. Environmental cues may differ between a plant s native and adopted range. It is also possible that predators and diseases that affect the species in its native range are not present here, and as a result the invasive plants are able to devote energy to growth and fruit production instead of chemical compounds to combat their natural enemies. In general, invasive plants tend to grow vigorously in a range of conditions and produce a high number 2

4 of viable seeds and/or reproduce rapidly through root cloning. The seeds of fruit producing species are often dispersed long distances by wind, birds, other animals or water. Some species have thorns, spines or chemical compounds that deter herbivores such as deer or insects. In addition, several species of invasive plants, such as shrub honeysuckle (Lonicera spp.) and Japanese barberry (Berberis thunbergii), leaf out earlier in the spring and/or hold their leaves longer in the autumn compared with the native, deciduous trees in the overstory. This trait gives the invasive plants a longer growing season and enables them to capture light, water, and nutrients when the overstory is dormant. Understanding the specific ecological traits of an invasive species helps land managers to plan more effective monitoring and control. For example, the seeds of garlic mustard (Alliaria petiolata) can persist in the soil seed bank; even after mature plants are removed, seeds will continue to germinate for many years. By contrast, the seeds of Asiatic bittersweet (Celastrus orbiculatus) do not remain viable in the seed bank for more than one year. If control can effectively stop seed production by killing vines before the fruits mature in late summer, few bittersweet seeds will germinate the next spring. Thus, a species seed bank longevity will determine monitoring schedules and the time it takes to achieve effective control. Other traits that are important to understand are: age of sexual maturity, season of fruit maturation, seed dispersal method, and tolerance of shade. Disturbance history Ecological disturbances that kill existing vegetation or disturb the soil can result from natural occurrences such as fire, windstorms, and heavy browsing by deer. Human activities such as logging, road building, and cultivation are also causes of ecological disturbance. Since disturbances free up growing space for new plants, they are necessary for native plant community succession and biodiversity. However, because invasive plants grow rapidly, produce large numbers of viable seeds, and may not be subject to herbivore damage, they often are able to exploit disturbances more readily than many native species. Due to the interaction between disturbances and invasive plant success, it is important to consider the effects of future disturbances. For example, shade tolerant invasive plant species such as Asiatic bittersweet (Celastrus orbiculatus), glossy buckthorn (Frangula alnus) and Japanese barberry (Berberis thunbergii) become established in the forest understory and can survive for years. An increase in light following the loss of established, dominant vegetation can release these plants and cause a small invasive plant population to explode. Less shade tolerant invasive plants, such as multiflora rose (Rosa multiflora) and autumn olive (Eleaganus umbellata) need more light and are more likely to become established in areas that have already been disturbed, such as old fields, large gaps, and forest edges. Disturbance to the forest litter layer is also an important factor in the establishment of invasive plants. Intact leaf litter can be a physical barrier to germinating seeds, especially in the case of small seeds that have limited starch reserves to support cotyledon and radicle growth. The surface of leaf litter can also be an extremely hot and dry micro-environment, creating harsh conditions for seedlings. When leaf litter is removed or disturbed it increases the amount of exposed soil and the chance that seeds will successfully germinate and become established. When there are a high number of viable invasive species seeds present, leaf litter disturbance often leads to invasive plant establishment. 3

5 Deer browsing is suspected of being an ongoing form of disturbance that affects significant areas of New England s forests. The dominance of invasive plants and lack of native tree and shrub regeneration in many New England forests may be due in large part to browsing deer that prefer to eat native vegetation instead of the invasive species. The selective pressure of deer browsing is thought to be especially important in the success of Japanese barberry, which deer avoid because of its sharp thorns. Even after barberry and other species are controlled, continued deer browsing should be expected to negatively impact native plant regeneration. Successful restoration of treated sites may require deer exclusion methods. Monitoring and Prevention Early detection and control of invasive plant populations avoids costly large scale removal projects and the accumulation of a soil seed bank. Monitoring should be a routine land management practice land owners should be vigilant while taking walks, foresters should include invasive plant surveys in their management plan updates, and land trusts should encourage committed and informed members to map populations. It is also important to take note of neighboring properties, as they can be a source of seed and neighbors may be willing to collaborate on plant control projects. When monitoring for invasive species, it helps to anticipate likely sites of invasion, such as roadsides, trailheads, logging sites, forest and water edges, sites in close proximity to invasive plant populations, and areas under fruitproducing plants that attract birds. Successful prevention depends on early detection and control combined with limiting disturbance so as not to create the light and leaf litter conditions that allow invasive plants to become established and grow rapidly. If seed rain from invasive plants is a threat, foresters should reduce leaf litter disturbance by limiting logging to the winter when the snow pack protects the forest floor. If a forest stand is scheduled for logging or thinning, it should be surveyed for the presence of invasive plants that could be released by the increase in light. The plants should be controlled before logging because control can be hindered by logging slash. Planning Control and Restoration Define objectives and assess resources Invasive plant control is an ongoing, multiyear effort that requires careful planning for the initial control work, follow-up, and restoration of native species. Sites will require different levels of treatment ranging from minor hand-pulling of invasive plants to complete ecosystem restoration. It is important to determine what the goal of a project is: Is it to protect established, native plants? Remove invasive plants? Stop an invasive population from spreading or fruiting? Restore a functioning native plant community? Is the goal realistic given the ecological characteristics of the site and the resources available for control? The feasibility of a project will be determined by ecological factors, such as the difficulty of controlling a particular species and the availability of funding and labor. It is important to predict the economic and/or volunteer resources that will be available for the initial control project, for planting native species, and for ongoing maintenance. Also, some sites, such as 4

6 wetlands, may have restrictions on the type of work that can be performed or require permits. All of these factors should be assessed before a project is undertaken. When managing property, there is always more work than there are hours in the day; pick battles carefully! One important consideration when planning control is to ask whether the goal is to remove invasive plants or to manage for native plants in spite of invasive plants. For example, should all the honeysuckle be removed from a site, or only those that are in direct competition for established white pine or native shrubs, such as Viburnum and spicebush? Both may be valid strategies, but each has very different ecological and economic consequences. Prioritizing sites Due to the ecological and economic limitations on certain projects, prioritizing sites is very important. In general, it is best to start control in intact native plant communities in which invasive species are just becoming established. These native plant communities with satellite invasive plant populations can be protected with a low investment in labor and materials. Other high priority sites are forest stands that are scheduled for logging or thinning. The sudden increase in light can release established invasive plants. It is preferable to conduct control before logging, as the resulting slash can make access difficult and cover target plants. After the satellite populations are controlled, areas with higher numbers of invasive species should be targeted, especially sites with seed producing, invasive plants. Large sites totally dominated by invasive plants are often the last to be controlled. These sites should be expected to require higher investments in control and replanting of native species. Who will do the work: volunteers, landowners or professionals? Depending on the property, invasive plant control may be conducted by landowners, volunteers, or by professional, licensed vegetation control specialists. Professional crews must be licensed and insured in your state and should be knowledgeable about common invasive plants and the native plants that should be protected. While landowners can apply unrestricted herbicides on their own property, a pesticide applicator s license is required to apply herbicides on another s land. Consulting foresters must have a valid commercial license to apply pesticides on their client s land. Under Vermont law, land trust members and employees require a non-commercial pesticide license to apply herbicides on land held by land trusts. Since use of herbicides is an important tool in combating invasive species, it is recommended that land trusts encourage several committed volunteers or local landscape contractors to obtain the proper license so that herbicides are an option on small control projects. Non-licensed workers can work under a license holder as long as the license holder is on the job site. For information on the different pesticide categories and for specific information on the laws governing the use of pesticides in Vermont, visit In the case of land trusts or public lands, volunteers can be an integral component in invasive plant control efforts. Surveying and monitoring invasive species populations are excellent activities for volunteers. Maps and photos of common invasive plants should be provided. Volunteers can perform useful invasive species control work in appropriate sites: those with species that can be effectively controlled through mechanical methods; those that are easily 5

7 accessed for repeat treatments; and those where follow-up control is required. Replanting native species following control is also an excellent task for volunteers. When organizing volunteers for control or restoration efforts it is important to clearly define the goals for the day, delineate project boundaries, and flag invasive plants that are to be removed or native plants that are to remain. When working with larger groups of volunteers, it is often helpful to divide the group into pairs and the project area into several work zones. Each pair can proceed from zone to zone at its own pace. Control Methods Mechanical Cutting and pulling invasive species are the most common methods of mechanical control. While they can be effective for certain invasive species, others respond by putting out more sprouts, which makes the problem worse. Cutting/Mowing: The time of year is an important factor when using cutting to control woody plants. Cutting plants in the spring just as the plant leafs out is the most effective. At leaf out, the plant s roots are depleted of stored carbohydrates as they move from the roots to the branches in order to feed new growth. Removing the above-ground biomass at this time maximizes the removal of carbohydrates. Subsequent cutting of resprouting stems throughout the summer will further deplete the roots. By contrast, cutting during the winter does not remove as many stored carbohydrates, and the plant will resprout vigorously in the spring. Cutting or mowing a plant before its fruits mature can reduce its seed production. For example, cutting in mid-summer can be used to stop seed production in Asiatic bittersweet (Celastrus orbiculatus) vines. However, for cutting or mowing to effectively control the overall vigor and spread of an invasive plant population, it must be done several times during the growing season (June through September) and repeated for many years. Often, cutting is practical only when it can be integrated into an existing field mowing plan. Pulling: Pulling plants out of the ground can be effective on species that have shallow roots and that do not reproduce through root suckering. For example, it is often possible to pull out most of the root system of glossy buckthorn (Frangula alnus) and garlic mustard (Alliaria petiolata). Some sprouting might occur, but reasonable control may be achieved. By contrast, species such as Asiatic bittersweet and Japanese knotweed (Polygonum cuspidatum) have extensive root systems that are hard to remove and that resprout vigorously from small sections of root left in the ground. While it is hard to control these species through pulling, if one comes across small, satellite populations of Asiatic bittersweet or other species, it may be worth the time to pull them out to reduce the plant s vigor. One downside of pulling is that is disturbs the soil, which may provide a seed bed for other invasive plants to become established. Pulling of plants can be aided by the Weed Wrench, a metal lever that grabs the base of small trees and shrubs. 6

8 Herbicides Note on herbicides This booklet provides an overview of the techniques that are commonly used to control invasive plants with herbicides. The use and handling of herbicides and other pesticides are regulated by state and federal laws. It is the responsibility of the landowner and any employees or contractors to adhere to state and federal pesticide laws at all times. The organizers and contractors working on The Northeastern Area Invasive Forest Plant Species Project assume no liability for the improper or illegal use of pesticides by workshop attendees or any of their employees or contractors. The Northeastern Area Invasive Forest Plant Species Project does not endorse the use of any particular herbicide, nor does it guarantee that the invasive plant control methods outlined in this plan will be effective. For more information on the laws governing the use of pesticides in Vermont please contact: Vermont Agency of Agriculture, Food & Markets 116 State Street, Drawer 20 Montpelier, VT Phone: (802) Fax: (802) Common herbicide application methods The method one uses to apply herbicide depends on such factors as target species, site characteristics, herbicide type, and time of year. The most common herbicides used for invasive plant control are systemic herbicides such as glyphosate (e.g., Roundup) and trichlopyr (e.g., Garlon), although other herbicides are available and are preferred in some cases. Wetland approved herbicides may be required near waterways in accordance with Vermont regulations. Systemic herbicides kill the plant by being absorbed into, and translocated throughout, the plant tissue. It is important to apply herbicides when the plant is translocating carbohydrates down to the roots (from early summer to early winter). It is also important to apply enough herbicide to the aboveground parts of the plant to kill all the roots. With the cut-stump method, concentrated herbicide is applied to a small surface area (the stump). Conversely, with foliar spray, a low concentration of herbicide is applied to a large surface area (all the leaves). Foliar spray will not kill the plant if it is applied only to a small percentage of leaves. Regardless of method, it is important not to cut stems or roots of target plants for at least 6 months to a year after the herbicide is applied. Herbicide takes months to work its way through the plant s vascular system, and cutting may disrupt its flow to living tissue. 7

9 Foliar spray Foliar application of herbicides entails spraying the leaves of target plants during the growing season with a low concentration of herbicide (0.75 3%) in water. Marking dyes, anti-drift formulations, and surfactants should be added in accordance with the pesticide label. The spray can be applied with a hand-powered, backpack sprayer or larger, motorized sprayers. When applying foliar spray, cover all the foliage with the solution. Foliar spray treatments should be conducted between early July and mid-september. At all times, applicators should be aware of herbicide drift. Applicators should spray with their back to desirable vegetation, sensitive areas, and waterways, and avoid spraying during windy days. Lowering tank pressure and setting the nozzle opening wider (more stream than spray) will lessen the potential for drift. If spray contacts the foliage of desirable vegetation, immediately cut off the affected leaves or branches to minimize the absorption of herbicide. One should avoid spraying tall vegetation. In addition, the herbicide can take many months to travel from the leaves to the roots; therefore, it is important to wait at least a Foliar spray year before cutting the stems of woody vegetation treated with foliar spray. Cut-stump The cut-stump method entails cutting vegetation near the ground and applying % concentrate herbicide to the stump or stumps (in the case of multiple stemmed plants). Herbicides should be applied immediately after the cut is made and should cover the plant s cambial tissue around the rim of the stem. Marking dye should be added to the herbicide to indicate which stems have been treated. Cuts often are made with hand saws or pruners, but chainsaws or gas-powered brush saws may be used on larger stems. Herbicide may be applied with paint brushes, squirt bottles, foam applicators (e.g., bingo markers), and the Sprout-Less system, which mounts on a brush saw and applies while it cuts. In addition to protective equipment specified on the pesticide label, eye protection and chemical resistant gloves should be worn at all times. The cutstump method is time consuming, but it is very selective. It should be used near sensitive, desirable vegetation and on target plants that cannot be foliar sprayed without a high risk of drift (e.g., tall shrubs, trees, or vines). The cutstump method can be used any time the plant is translocating sugars through the cambium down to the roots. The general period for this activity is from early July through November, although Cut-stump there is some evidence that fall application is more effective. 8

10 Basal spray The basal-spray method involves the application of an oil-based herbicide and oil dilutant to the bottom portion of a plant s stem. The oil penetrates the plant s bark and carries the herbicide into the cambium for translocation to the roots. Basal treatments generally are applied using a sprayer at low pressure with a marking dye. The concentration of herbicide in oil is dependent on the product being used and the application type. Consult pesticide labels for treatment methods and mixture instructions. The basal-spray method is similar to cut-stump application in that it is highly selective and may be used from early July through December. It tends to be faster than cut-stump because cutting is not required, but may require the application of more active ingredient. Basal Basal spray spray formulations can also be applied to cutstumps that have begun to re-sprout. Reducing non-target kill It is important to avoid the unintentional killing of non-target species. Follow the application guidelines outlined on the product label to reduce herbicide drift. Use common sense and caution at all times. In some cases some non-target kill will occur. If spray contacts the foliage of desirable vegetation, immediately cut off the affected leaves or branches to minimize the absorption of herbicide. One way to reduce non-target kill is to protect a significant portion of the desirable species before treatment begins. For example, in the week before a scheduled foliar spray application, desirable plants close to or overgrown by invasive plants should be cut cleanly at the stump. Many species will resprout the following year. Another tactic is to limb the lower branches of small trees so that low-lying leaves will not be hit by herbicide. The evening before spraying, especially desirable plants can be covered with plastic sheeting, garbage barrels, traffic cones, etc. It is important not to leave the plastic on for more than a few hours during the day, however, because heat stress will kill the plants. Often, there are so many desirable plants that it is unrealistic to protect them all. Limit pre-spray protection to rare species, those that are important to wildlife or timber production, or to species that will quickly occupy growing space after control. Be careful not to cut target, invasive plants before spraying because the translocation of herbicide to the roots will not occur and control will be reduced. Please note that invasive species may form root grafts with desirable native plants. While not common, herbicide applied to an invasive plant might be translocated through the roots and damage non-target vegetation. 9

11 Restoration/Replanting Following the removal of invasive plants, the site should be evaluated for the vigor, density, and diversity of established native plants. Many native plants might survive the initial control, new ones may seed in, or seeds may germinate from the seed bank. In many cases, however, it is often necessary to replant native species to ensure that the site s growing space is occupied; otherwise invasive species will recolonize the site. Restoring a site with the original array of native species can be quite expensive and time consuming. In very sensitive sites with rare plant or wildlife species such an expense may be warranted. Often, though, the main goal of replanting is to quickly occupy growing space after control with fast-growing or easy-to-establish native species that grow in a range of conditions. Select native species that are appropriate for the site. For example, if the site is in the understory, plant shade tolerant species; if the site s soil is wet or compacted by vehicles, plant trees such as red maple (Acer rubrum), which tolerate poor soils; if heavy deer browsing is a problem, plan on installing adequate fencing, plastic tree tubes or choose unpalatable native species, such as eastern white pine (Pinus strobus) or black birch (Betula lenta). Before planting, evaluate whether invasive plant control was thorough. Delay planting or use plastic tree tubes to protect planted stock if yearly foliar spraying of herbicides is required to control resprouting plants or seed bank emergents. While they are often hard to find, try to buy plants that come from local genotypes. Also be aware that many nursery-grown shade tolerant species have spent their lives in full sun and they might experience shock if planted in dense shade without acclimating. Nursery stock can be a vector for disease or have weed seeds in their potting soil check plants carefully. One option to reduce the threat from weed seeds is to plant bare root stock, which tends to be less expensive and in some cases has higher transplant success. One of the most common reasons for transplant failure is that stock is planted too deep and the roots are smothered. It is important to learn to locate the root flare at the base of the stem and install the plant so that the flare is slightly above ground level. Also, it is important to schedule planting in the spring or fall to reduce watering needs. 10

12 Guide to Demonstration Plots Note: Due to the time limitations on this project, all control work was conducted during July and August of Methods such as cut-stump and basal spray tend to be more effective in the fall when the plant is more actively translocating carbohydrates down to the roots. As a result, a reduced efficacy in those plots should be expected. Site #1: Asiatic bittersweet control site (Scott Farm, Inc., Dummerston, VT) Description Site #1 is located in a white pine stand along a field edge. Asiatic bittersweet had become established in the understory and was climbing up the low hanging branches and trunks of the canopy trees. The age of the invasion is not known. Few native plants were present in the understory, primarily black cherry (Prunus serotina) and raspberry (Rubus spp.). The invasive shrub, common buckthorn (Rhamnus cathartica), was also present. The site was divided into treatment and control plots in order to demonstrate the scope of the work performed. The control plot had less bittersweet than the treated plot, but it had a similar structure (understory and climbing plants). In addition, a small subplot was delineated within the control plot in which all native plants were cut the day before foliar spraying so as to protect them from the effects of the herbicide. Because of the presence of both low lying and climbing vines, the control work was scheduled for two separate days. The larger vines climbing into the trees were cut at about 5 feet high and at ground level with bypass loppers or hand pruners. The cut surfaces of the stumps were painted with 100% Garlon 4 herbicide and Bas-Oil Red dye in a heavy-duty bingo marker (similar to a postage stamp applicator). Vines that ran along the ground were carefully traced to each descending root and cut for additional application. The following day, the low-lying vines were sprayed with Garlon 4 at a 2.5% solution in water. Blue marking dye and 41-A anti-drift additive were added at label rates. On very hot days Garlon 4 can volatize and drift into the forest canopy check manufacturer specifications before applying. 11

13 Work summary (Asiatic bittersweet) Location: Treatment plot. Description: Cut-stump application to climbing bittersweet. Date: July 6th, Weather: High 70 s and muggy. Tools used: Bypass loppers, bypass pruners, bingo marker applicator. Chemical used: 100% Garlon 4 (EPA Reg. # ) with Bas-Oil Red marking dye. Amount used: 2 oz. Time: 1 hour, 35 minutes. Notes: On vines running along the ground, care was taken to trace them back to the roots. Location: Native plant cut plot (within control plot). Description: Cutting of native plants in preparation of foliar spray. Date: July 6th, Weather: n/a Tools used: Bypass pruners and loppers. Chemical used: n/a Amount used: n/a Time: 10 minutes. Bittersweet site before control Cut-stump technique Location: Treatment plot. Description: Foliar spray of low-lying bittersweet and occasional common buckthorn. Date: July 7th, Weather: 70 s, calm with occasional breeze. Foliage wet from heavy rain the night before. Tools used: Solo 4 gal. backpack sprayer w/ brass cone nozzle. Chainsaw to trim large pine boughs hit by spray. Chemical used: 2.5% Garlon 4 (EPA Reg. # ), with blue marking dye and 41-A anti-drift additive at label rates. Amount used: 19.2 oz. concentrate to 6 gallons of water. Time: 45 minutes of spraying, 30 minutes preparation and tank mixing. Notes: Goal was full coverage of leaves with spray solution. Effort was made to avoid spraying the leaves of non-target natives. Leaves of bittersweet vines that had been cut the day before were already wilting. Cut-stump technique 12

14 Site #2: Honeysuckle control site (Elysian Hills Tree Farm, Dummerston, VT) This site was clear-cut in 1995 to promote bigtooth aspen (Populus grandidentata) regeneration for wildlife habitat. Instead, exotic shrub honeysuckle became established and began to dominate the site. Scattered glossy buckthorn, common buckthorn and Japanese barberry were also present. There was evidence of heavy deer browsing on native plants besides the relatively unpalatable black birch (Betula lenta) and eastern white pine (Pinus strobus) and it is possible that selective browsing may have been a factor favoring honeysuckle and other invasive species. The site was divided into 4 plots in order to demonstrate the following techniques: cut-stump application of glyphosate by a two-person team, cut-stump application of glyphosate using the Sprout-Less Brush Saw applicator, foliar spray of glyphosate, and basal spray application of trichlopyr. Cut-stump and basal spray application are known to be effective on controlling shrub honeysuckle, while the foliar spray has been reported to have mixed results. When comparing the longterm efficacy of the cut-stump hand treatment (Plot 1) and the Sprout-Less treatment (Plot 2), attendees should Plot 4 Plot 3 consider that Plot 2 was treated 3 weeks later, at a time when downward translocation of sugars was more likely. Honeysuckle site before control 13

15 Work summary (Honeysuckle) Location: Plot 1 Description: Cut-stump herbicide application. Date: July 18 th, Weather: Hot, humid, overcast. Tools used: One person running a chainsaw or loppers, one person with bingo marker style applicator. Chemical used: 100% Glypro (EPA Reg. # ) and blue dye. Amount used: 5.5 oz. Time: 2 hours (4 hour labor cost due to two person crew). Notes: Heavy rain soon after application. Early in season for cut-stump reduced efficacy? Cut-stump technique: Plot 1 Location: Plot 2 Description: Sprout-Less brush saw application. Date: August 11 th, Weather: Hot and humid. Tools used: Sprout-Less brush saw applicator and Husqvarna 250 brush saw. Chemical used: 100% Glypro (EPA Reg. # ) and blue dye. Amount used: 4 oz. Time: 1.5 hours. Notes: Location: Plot 3 The Sprout-Less System Description: Foliar spray. Date: July 25 th, Weather: Hot, humid, overcast, calm. Tools used: 4 gallon Solo backpack sprayer, adjustable brass cone nozzle. Chemical used: 2% Glypro (EPA Reg. # ), with marking dye and 41-A anti-drift additive at label rates. Amount used: 5 oz. concentrate in 2 gallons of water. Time: 20 minutes. Notes: Since vegetation was high, effort was made to fully cover lower and mid-level foliage. Upper foliage was sprayed when it was possible not to cause Plot 1 after cut-stump treatment drift on to non-target plants. Spray was directed away from desirable white pines and black birch when possible and leaves were removed when they were hit by spray. Some non-target application occurred. 14

16 Location: Plot 4 Description: Basal spray. Date: July 25 th, Weather: Hot, humid, overcast. Tools used: 4 gallon Solo backpack sprayer, adjustable brass cone nozzle. Chemical used: Pathfinder II (EPA Reg. # ) and Bas-oil red marking dye. Amount used: 103 oz. Time: 45 minutes. Notes: Applied to bottom inches on all stems. Basal spray technique: Plot 4 Site #3: Glossy buckthorn control site (Aquadro property, Dummerston, VT) The glossy buckthorn control site is located within a white pine stand. Glossy buckthorn dominated the forest understory and midstory. A significant number of sugar maple (Acer saccharum) was also present in the midstory. The site was divided into 4 plots: cut-stump application of glyphosate by a two-person team, cut-stump application of glyphosate using the Sprout-Less Brush Saw applicator, basal spray application of trichlopyr, and a no treatment control. A buffer of untreated vegetation was also left along the edge of the lawn to provide a screen for the property owner. 15

17 Work Summary Location: Plot 1 Description: Sprout-Less brush saw application. Date: August 11 th, Weather: Hot and humid. Tools used: Sprout-Less brush saw applicator and Husqvarna 250 brush saw. Chemical used: 100% Glypro (EPA Reg. # ) and blue dye. Amount used: 3.5 oz. Time: 60 minutes. Notes: Location: Plot 2 Description: Basal spray. Date: July 25 th, Weather: Hot, humid, overcast. Tools used: 4 gallon Solo backpack sprayer, adjustable brass cone nozzle. Chemical used: Pathfinder II (EPA Reg. # ) and Bas-oil red marking dye. Amount used: 110 oz. Time: 1 hour, 10 minutes. Notes: Applied to bottom 10 inches on all stems. Careful not to have runoff from buckthorn stems around the base of canopy pines. Buckthorn site before control: Plot 2 Plot 3 after cut-stump treatment Location: Plot 3 Description: Cut-stump herbicide application. Date: July 18 th, Weather: Hot, humid, overcast. Tools used: One person using loppers, one person with bingo marker style applicator. Chemical used: 100% Glypro (EPA Reg. # ) and blue marking dye. Amount used: 1 oz. Time: 40 minutes (1 hour, 20 minutes labor cost due to two person crew). Notes: Heavy rain before application. Early in season for cut-stump reduced efficacy? Site #4: Japanese barberry control site (Evans property, Dummerston, VT) The control work on Site #4 was conducted on the Evans property during the summer of 2004 with funding from the USDA Wildlife Habitat Incentives Program (WHIP). Ellsworth Land Management, LLC was hired under a private contract to perform the work. The primary target of the control work was Japanese barberry (Berberis thunbergii) which dominated the site. Common barberry (Berberis vulgaris), common buckthorn (Rhamnus cathartica), Asiatic bittersweet (Celastrus orbiculatus), and winged euonymus (Euonymus alata) were present and were also targeted. The majority of the Japanese and common barberry was controlled using a glyphosate (Glypro or Accord) foliar spray at 2.5% applied with backpack 16

18 sprayers. Large shrubs in gaps and along the field edge were treated with 100% glyphosate using the cut-stump method. The Sprout-Less system was used in limited areas. Large Asiatic bittersweet vines were treated with Garlon 4 applied using the cut-stump method. A visit to the Evans property has been included in the NEA Invasive Project workshop because it allows attendees to view several things: an example of Japanese barberry control work, how a site looks a full year after control was completed, and the labor and material costs involved in a large sized control project. Work summary Location: Evans Property Area treated: 8.4 acres. Description: Foliar spray of Japanese barberry and other invasive plants. Cut-stump method used on tall shrubs and vines. Date: August 3 rd through September 14 th, Weather: Warm, calm. Tools used: 4 gallon Solo backpack sprayer, adjustable brass cone nozzle. Barberry 1-year after foliar spray Sprout-Less brush saw applicator. Bingo marker herbicide applicator. Chemicals used: Foliar spray: 2.5% concentration of Glypro (EPA Reg. # ) or Accord (EPA Reg. # ) with marking dye, surfactant, and 41-A antidrift additive at label rates. Cut-stump: 100% Glypro (EPA Reg. # ) or Accord (EPA Reg. # ) and blue marking dye. 100% Garlon 4 (EPA Reg. # ) with Bas-Oil Red marking dye used on bittersweet. Amount of concentrate used: Glypro 2.2 gallons Barberry 1-year after foliar spray Accord 0.4 gallons Garlon oz. Time: 55 labor hours (including preparation, clean-up, and tank mixing). Approximately 110 gallons of 2.5% spray mixture were applied. Notes: Spray was directed away from desirable plants when possible and leaves were removed when they were hit by spray. Some non-target application occurred. 17

19 Common Invasive Species Found in New England Forests Shrubs/trees Japanese barberry (Berberis thunbergii) Common barberry (Berberis vulgaris) Shrub honeysuckle (Lonicera spp.) Winged euonymus (Euonymus alata) Norway maple (Acer platanoides) Multiflora rose (Rosa multiflora) Autumn olive (Eleaganus umbellata) Common buckthorn (Rhamnus cathartica) Glossy buckthorn (Frangula alnus) Vines Asiatic bittersweet (Celastrus orbiculatus) Herbaceous Japanese knotweed (Polygonum cuspidatum) Garlic mustard (Alliaria petiolata) Goutweed (Aegopodium podagraria) Invasive species that could become a serious threats in Vermont Japanese stilt grass (Microstegium vimineum) Mile-Minute-Vine (Polygonum perfoliatum) Black swallow-wort (Cynanchum louiseae) Pale swallow-wort (Cynanchum rossicum) Porcelainberry (Ampelopsis brevipedunculata) Invasive Species: Descriptions, Ecological Traits, and Control Note: This section outlines general plant traits and control techniques. Further information on plant identification and specific control methods are available in print and on numerous websites several of which are listed in the Additional Resources section of this booklet. Asiatic bittersweet (Celastrus orbiculatus) Description Asiatic bittersweet is a woody, twining vine with deciduous, alternately arranged leaves. It can climb high into tree tops, or grow in a low shrub like form in open areas. New stems are light green and second-year (or older) stems are brown to gray. Leaves are oval or circular in shape. The flowers and fruits of Asiatic bittersweet are located in groups at the base of leaves, along the stem. The fruits mature by early fall and have a yellow covering that recedes to expose fleshy red or orange axils that contain the seeds. Asiatic bittersweet spreads through seed dispersal by 18 Asiatic bittersweet Photo Courtesy of IPANE

20 birds and mammals and through root suckering. It can become established and survive in dense shade (shade tolerant), but it grows rapidly when light levels increase. Evidence suggests that the seeds of Asiatic bittersweet do not remain viable in the seed bank past one year. Control Mechanical control of bittersweet is limited. Small- to medium-sized bittersweet plants that are not growing in dense clumps can be hand pulled, but any roots left in the ground will resprout. Large vines that are strangling trees or are producing fruit should be cut by mid- August, before the fruits mature. Cut the vines as high as possible and down at ground level. Don t try to pull vines out of the host tree--it will only damage the crown. Asiatic bittersweet can be controlled with herbicides. Foliar spray low-lying vines (below head height) during July through early-september. Cut-stump application should be used on larger bittersweet vines when foliage has climbed above an acceptable spraying height. It is important to note that herbicides containing the active ingredient trichlopyr are the most effective on bittersweet. Large and small vines may be treated at different times. Cut-stump application can be conducted on large, high climbing vines in the fall and then smaller, surviving stems can be foliar sprayed the following summer. The reverse order may also be used, with an initial foliar spray in the summer followed by cut-stump on large vines in the fall. If possible, control fruiting vines before the fruits mature in September. Japanese barberry (Berberis thunbergii) Description Japanese barberry is a spiny, deciduous shrub with arching branches. Plants commonly range from 2 to 6 feet high. Japanese barberry flowers from mid-april to May in the Northeast and the fruits mature from July to October. The branches are brown and covered with sharp spines. The interior of the stems are bright yellow (apparent when the stems are cut or broken). The leaves are teardrop to oval in shape, and are inches long. Leaf color ranges from bluish-green to green to dark red or purple, although its new leaf growth is light green. Japanese barberry leafs out before many native plants in the spring, at which point its light green Japanese barberry foliage becomes very noticeable. It has pale yellow flowers and football-shaped, bright red berries ( inches long) that hang like pendulums along the length of the stem. Japanese barberry reproduces by seed and clonally when arching branches touch the ground and form roots. It is can become established and survive in dense shade (shade tolerant), but can grow rapidly when light levels increase. The spines Photo Courtesy of IPANE deter deer. Control Hand-pulling of Japanese barberry in the spring may be effective at controlling seedlings and small plants, although roots left in the ground will give rise to new shoots. Due to the sharp spines, long sleeves and heavy-duty, leather gloves should be worn. Japanese barberry can be controlled with foliar and cut-stump applications of herbicide. Foliar spray treatments should be conducted between early July and mid-september. Cut-stump application should be used 19

21 in the fall. Follow-up treatment methods are the same as those used initially. May is a good time for monitoring Japanese barberry because it leafs out earlier than many other plants and is easy to locate. Do not spray before July, however, because during the spring plants are translocating their sugars away from the roots. Shrub honeysuckcle (Lonicera spp.) Description There are many species and ornamental crosses in the honeysuckle family, and telling them apart can Shrub honeysuckle be quite difficult. Therefore, for the sake of management, they are lumped together as shrub honeysuckles (as opposed to vine honeysuckles). Shrub honeysuckles have grayish to brown woody bark and grow in an arching shape. The light green leaves are oblong and oppositely arranged on the stem. The stems of the exotic honeysuckles are hollow. The flowers range from yellow to white to red in color (depending on the species) and the fruits are fleshy and bright red. The fruits of the different species mature from mid-summer to mid-autumn. Shrub honeysuckles are shade tolerant and leaf out earlier in the spring than many native plants. It has been reported that the seeds remain viable in the soil seed bank. Control Honeysuckle sprouts vigorously from the stump so cutting is ineffectual. Honeysuckle has a relatively shallow root system; therefore, pulling has been reported to work in some instances care must be taken to remove as much root as possible. Foliar, cut-stump and basal spray herbicide applications are reported to control shrub honeysuckles. If possible, treat honeysuckle before the fruits mature. Honeysuckle seeds are reported to remain viable in the seed bank for many years. Therefore, treated sites should be monitored yearly for new seedlings and treated accordingly. Winged euonymus/burning bush (Euonymus alata) Description Euonymus alata is a woody, deciduous shrub with oppositely arranged, dark green leaves that turn bright red in autumn. It is named winged euonymus because most cultivars have 2 4 corky flanges, or wings, that run along the branches. Euonymus alata flowers from late April to June and the reddish-purple fruits mature in September or October. Each fruit contains 4 seeds, which are dispersed by birds and gravity. Euonymus alata tolerates a range of light levels and soil conditions and, therefore, is a threat in both understory and open environments. The seed bank longevity is not known, although anecdotal evidence suggests that its seeds do remain viable in the seed bank. Winged euonymus Photo Courtesy of IPANE 20

22 Control Euonymus seedlings may be pulled out in the spring when the soil is moist. Try to control larger plants before the fruits mature in September. Euonymus may also be treated with a foliar herbicide application. Plants that are too tall for foliar spray can be controlled with cutstump or basal bark applications. Monitor treated sites for new seedlings, seed bank emergents, and plants that were missed in the initial treatment. Japanese knotweed (Polygonum cuspidatum) Description Japanese knotweed is an herbaceous perennial that grows rapidly, reaching 3 10 feet in height, and forms dense Japanese knotweed monotypic stands. The stems are round and hollow and Japanese knotweed the leaves are oblong and large (3 6 inches across). Japanese knotweed produces greenish-white flowers in clusters from the top of the plant in August and September. The fruits are winged and papery, each containing 3 black achenes. Despite fruit production, Japanese knotweed reproduces primarily through rhizomes, which grow up to 65 feet in length and give rise to new shoots. It dies back with the onset of frosts in the fall, leaving dead, brown-to-purplish stalks throughout the winter. Japanese knotweed grows well in most soil conditions, but prefers wet soils and riparian areas. It tolerates moderate shade, but is not often found in dense understories. Control Due to its capacity for rapid and prolific vegetative reproduction, Japanese knotweed is particularly difficult to control. Pulling is ineffective and cutting will only work if it occurs often, consistently, and over the long-term, as in a lawn setting. Herbicides can be moderately to highly effective. One method is a cut-stump application. Another is to cut the plant between leaf nodes and inject the hollow stem with 35% solution aquatic glyphosate and water. Foliar spray in late August may also work on mature plants, or on plants that have been cut down and allowed to resprout. Multiflora rose (Rosa multiflora) Description Multiflora rose is a perennial shrub with arching canes. It grows up to 15 feet tall, but it can grow higher when it uses trees or other structure for support. The canes are red to green in color and have recurved thorns. Its leaves are alternately arranged and are compound, having 5 11 toothed leaflets. The leaflets are inches long. Multiflora rose has white to pink flowers that come out during May and June. The fruits are red and develop by mid- to late summer. Multiflora rose reproduces via seeds that are dispersed by birds and by layering (when canes send up new shoots after 21 Rosa multiflora Photo Courtesy of IPANE