To Invasive Phragmites Australis in Minnesota
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An assessment to support strategic, coordinated response to invasive Phragmites australis in Minnesota Chelsey Blanke, Daniel Larkin, Julia Bohnen, Susan Galatowitsch University of Minnesota Department of Fisheries, Wildlife, and Conservation Biology Minnesota Aquatic Invasive Species Research Center 1 May 2019 Acknowledgements Funding for this project was provided through Sheryl Bock and Randy Thorson (MPCA); Eric the Minnesota Aquatic Invasive Species DeVenecia and Frederick Hegeman (Wisconsin Research Center (MAISRC) from the Minnesota DNR); Miles Falck (GLIFWC); and Chad Abel and Environment and Natural Resources Trust Fund. Gabrielle VanBergen (Treaty Natural Resources Division of the Red Cliff Band of Lake Superior Control cost information was provided by Dan Chippewa). Shaw and Carol Strojny (BWSR); Bill Bartodziej (Natural Shore Technologies, Inc.); Mike Reviewers who provided helpful suggestions on O’Connell (Lake Management, Inc.); Tory earlier versions of this assessment include Christensen and Patrick Kelly (Landbridge Wendy Crowell, Allison Gamble, Keegan Lund, Ecological); Patrick Selter (PLM Lake and Land and Laura Van Riper (MNDNR); Monika Management Corp.); Lee Shambeau (4 Control); Chandler (MDA); Sheryl Bock and Randy Mike Hiltner (Prairie Restorations, Inc.); Doug Thorson (MPCA); Mary Jo Youngbauer (Chisago Mensing (Applied Ecological Services, Inc.); Dale County SWCD); and Brandon Van Tassel Sutherland (Nutrien Ag Solutions); Keegan Lund, (Community Action Duluth). Ray Norrgard, and Ricky Lien (MNDNR); and We also extend our thanks to the many Dave Hanson (MNDOT). individuals who have reported, submitted Information related to the use of invasive samples, and continue to scout for invasive Phragmites at wastewater treatment facilities Phragmites populations throughout the state. and alternative approaches was provided by 2 Assessment summary Invasive Phragmites (Phragmites australis environmental contexts in which invasive subsp. australis) has spread across the wetlands Phragmites occurs across Minnesota, and to of many regions of North America, and is well- empower regional and local organizations to documented to have detrimental effects on quickly mobilize and initiate response efforts. wildlife, fish, native plants, water supply, and Some regions include many populations with recreational uses. This tall, fast-growing, non- various sizes, habitats, and property native wetland grass spreads to lakeshores, ownerships, while others include only a few wetlands, roadside ditches, and other wet populations under similar invasion contexts. habitats, sometimes after intentional Each regional section contains a description of introduction, as occurred in Minnesota. the regional status of invasive Phragmites, Numerous reports over the past ten years had potential partner organizations and funding suggested that the invasion of this species was options, estimated control costs, and training progressing in Minnesota and that the window and capacity needs. of time might be closing to efficiently respond Review of the scientific literature shows the and prevent widespread damage to the state’s most effective approach for controlling invasive wetlands. Over the last two years, our research Phragmites to be end-of-summer herbicide has verified 389 invasive Phragmites treatment, supplemented by winter or late populations in Minnesota. Many populations summer mowing to remove dead stems. It is are producing viable seed and so have high likely that this management schedule will need capacity for further spread. However, these to be repeated for three years to eliminate the numerous populations currently add up to an plant from most sites. While burning, cutting, area of approximately 50 acres. In light of these and water-level management have also been findings, a coordinated, statewide control effort employed in invasive Phragmites management, with the aim of eliminating all established these approaches have either been shown to be populations is still feasible, if pursued without ineffective or come with important caveats. The delay. Invasive Phragmites has the capacity to type of equipment required to conduct control quickly spread and overtake areas; partial or (e.g., backpack sprayer, boat, etc.) will need to uncoordinated responses are unlikely to be be varied depending on characteristics of the beneficial or cost-effective. This assessment targeted site. Only equipment that can be suggests strategies for collaboration, sufficiently decontaminated of plant propagules coordination, and implementation of control should be used in conducting control to avoid efforts; provides control cost estimations; contributing to invasive Phragmites spread. details core competencies for participating entities; identifies potential funding sources; In addition to wild invasive Phragmites and addresses possible challenges associated populations, there are 16 wastewater with such a response. treatment facilities in Minnesota that use invasive Phragmites in their operations. While We present invasive Phragmites status the invasive Phragmites at these facilities are information and possible response strategies potential sources of spread, they also support tailored to 12 regions of the state. This wastewater treatment operations by regionalized approach is intended to highlight dewatering biosolids following sewage differences in distribution and the social and treatment. Ultimately, a plan for transitioning 3 these facilities to effective, alternative (Phragmites australis subsp. americanus) or dewatering methods would be needed for a how to collect and submit specimens to an truly comprehensive response to invasive expert for identification. Those implementing Phragmites in Minnesota. While potential control will need to acquire the appropriate alternatives are being evaluated, best permits, follow applicable herbicide-use management practices to minimize spread risk regulations, and determine the control should be developed for facilities’ dewatering approaches and equipment needs specific to operations and materials disposal. each site. Adequate reporting and evaluation of control efforts will be needed to support An effective statewide response to invasive comprehensive response and to facilitate Phragmites is only possible with local to state adaptive management. level partners and partnerships. To varying degrees, invasive Phragmites falls under the Responding to invasive Phragmites statewide jurisdiction of multiple state agencies, including will require substantial financial investment at the Minnesota Department of Natural the outset. Several potential sources of funding Resources, Minnesota Department of to support invasive Phragmites response are Transportation, Minnesota Department of identified in this assessment. We have Agriculture, and Minnesota Pollution Control estimated costs for three years of herbicide Agency. Response efforts could be coordinated treatment and mowing of all verified wild by state agency staff – either by managing populations at $818,500-2,019,000. These costs control contracts directly or by administering are comparable to costs of invasive Phragmites funds to regional and local entities – or by control efforts conducted in other states, regional and local organizations implementing though Minnesota is unique in that this level of private or grant-funded projects from non- investment can be deployed at a time when agency sources. Cooperation with private and reversal of spread remains feasible. Should commercial landowners will be essential. potential partners choose to wait to implement Regardless of the level at which control efforts response efforts, control costs will increase as are organized, a truly statewide response will invasive Phragmites becomes more widespread require significant coordination, which could and difficult to manage, requiring more potentially be centralized and designed to work complicated equipment and more labor. It is across jurisdictions. We do not identify critically important to recognize that choosing “priority” populations for control in this not to respond is choosing to allow invasive assessment because a partial approach is Phragmites spread to escalate, and this choice inconsistent with the well-understood biology will severely limit the feasibility of control of this species—that all seed-producing within the not-too-distant future. populations have high capacity to trigger Mobilizing a strategic, coordinated response to broader spread. invasive Phragmites statewide is clearly an Participants in invasive Phragmites response ambitious undertaking that will come with should be trained in several core competencies many challenges. Lack of support from state, to ensure effective and responsible regional, and local entities; private landowners; management. Individuals conducting or grant programs would hinder efforts. surveillance for new populations must know Depending on the rate of invasive Phragmites’ how to report their findings and distinguish spread, the potentially short window of invasive Phragmites from the native subspecies opportunity for effective response requires 4 mounting efforts both quickly and responsibly. ongoing monitoring will be needed to support Coordinators will need to ensure that control early response to newly detected populations. efforts are of sufficient quality and include While the challenges are real, they are not adequate follow-up and equipment insurmountable, and overcoming them will decontamination. Potential pathways