Piermont Marsh: Fact-Finding Meeting 4: What do we know about methods of managing marsh vegetation? May 21, 2015, Piermont Village Hall, 6:00-8:30pm This was the fourth in a series of public fact-finding meetings to inform the development of a long-term management plan for Piermont Marsh by NYS Department of Environmental Conservation and NYS Parks. The goals of these meetings are to address a range of questions and concerns, build a foundation of scientific information to inform the plan, and provide an opportunity to ask clarifying questions of the presenters. The following summary aims to outline the key information presented by the speakers and capture the question and answer component of the meeting. Speakers included:

Gary Bickle, AKRF, Inc. Betsy Blair, NYS Department of Environmental Conservation David Decker, Constitution Marsh Audubon Center & Sanctuary Erik Kiviat, Hudsonia, Ltd. Chris Zimmerman, The Nature Conservancy

Content: 1. SUMMARY OF PRESENTATIONS

a. Introduction: Betsy Blair b. Marsh management considerations: Betsy Blair c. Phragmites management techniques: Erik Kiviat d. Restoration of Phragmites dominated marshes along the Delaware Estuary:

Gary Bickle e. Phragmites control and restoration at Constitution Marsh: David Decker f. Trajectory of native plant recovery: management of five Phragmites australis

stands in a Hudson River freshwater tidal marsh: Chris Zimmerman 2. QUESTIONS AND ANSWERS 3. COMMENTS 4. FEEDBACK FORMS

Summary of Presentations:

Marsh management considerations: Betsy Blair, NYS Department of Environmental Conservation/Hudson River National Estuarine Research Reserve

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The purpose of fact-finding meeting four is to investigate a variety of marsh vegetation management approaches and learn about two local examples of Phragmites control. Throughout the management planning process, a wide range of management outcomes and options will be explored in partnership with the community and regional experts. Current options being considered include restoring areas of native marsh vegetation, expanding the marsh to the east and south, and adding constructed habitats to support wildlife and provide storm protection. Management opportunities will be evaluated based on their feasibility and the benefits they provide to both natural and human communities. Management actions, at any given time, would only involve a portion of the marsh to allow for monitoring, assessment, and adaption.

Phragmites management techniques: Erik Kiviat, Hudsonia, Ltd. Many restoration and management projects seek to remove Phragmites despite poor understanding of its ecology, the nontarget impacts of removal, and the sustainability of alternate species. Management of an environmental weed should consider the pertinent characteristics of the species, and be goal-directed and site-specific. A possible goal for management at Piermont Marsh is to optimize the conservation of rare plants and high salt meadows, and non-habitat ecosystem services provided by Phragmites. A wide range of techniques have been used to manage Phragmites across the United States and Europe. Possible treatment techniques include herbicide, sulfide addition, solarization, frequent cutting, livestock grazing, classical and microbial biocontrol, and encouraging muskrat populations. Management decision-making should consider the potential advantages and disadvantages of each treatment method. Depending on management goals, site and stand factors, the surrounding landscape, and the local biota, it may be appropriate to take no action, remove a Phragmites stand, or alter the stand to change its habitat functions and ecosystem services. An explicit and documented decision-making process should be used to justify decisions and acquire information about management outcomes that can inform subsequent management.

Restoration of Phragmites dominated marshes along the Delaware Estuary: Gary Bickle, AKRF, Inc. A 20,000 acre wetland restoration project designed to increase aquatic production within the Delaware Estuary has been ongoing since 1996. The project includes restoration of diked salt hay farms, Phragmites-dominated wetlands, installation of fish ladders, and preservation of sensitive habitats. Historic aerial photography demonstrates the invasion of Phragmites into Delaware Bay marshes beginning in the 1950s and expanding exponentially through the 1970s and 1980s. The Phragmites-dominated wetland restoration aspects of the project have provided data regarding the success of various methodologies for controlling invasive forms of Phragmites. Large-scale aerial and ground application of glyphosate and LI-700 has proved effective in reducing Phragmites-dominated vegetation and replacing it with more desirable marsh species including Spartina spp. In addition, evaluation of marsh channel systems within the formerly Phragmites-dominated marshes have shown a significant increase in marsh

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channels and hence an associated increase in fish habitat as a result of Phragmites reductions. As part of the program, alternative methods were developed and evaluated to determine their effectiveness at managing invasive Phragmites. The alternative methods included microtopographic alterations, various mowing techniques and frequencies, alternative timing of herbicide application, grazing through the use of goats, and various combinations and frequencies of each of the alternative techniques. The non-herbicide techniques evaluated over a several year period were not effective in managing Phragmites on the marshes evaluated as part of the project.

Phragmites control and restoration at Constitution Marsh: David Decker, Constitution Marsh Audubon Center & Sanctuary Constitution Marsh Audubon Sanctuary is a 270-acre tidal marsh on the Hudson River. Phragmites australis was first detected in the marsh in the mid-1980s, and the current management efforts began in 2005. The main technique used to manage the largest patches of Phragmites in the marsh is the mechanical technique of solarization. This technique uses a geotextile to cover the outside edge of a Phragmites patch to prevent sunlight from reaching the plant as well as increasing the soil temperature. After two growing seasons, the Phragmites under the geotextile is destroyed and the geotextile is moved inward towards the center of the patch, slowly shrinking it. The preliminary results show that this method may be successful in control dense patches of Phragmites that are smaller than 1.5 acres. Solarization is only recommended for controlling dense patches of Phragmites because it is non-selective and will affect all native vegetation and damage soil biota. Chemical control of Phragmites is also being done at Constitution Marsh to manage small patches of Phragmites that are intermixed with native vegetation.

Trajectory of native plant recovery: management of five Phragmites australis stands in a Hudson River freshwater tidal marsh: Chris Zimmerman, The Nature Conservancy In order to guide management efforts in tidal wetlands, we assessed the effectiveness of multiple herbicide treatments in eliminating five small Phragmites australis (Phragmites) stands (0.040.75 ha) and evaluated the trajectory of vegetation recovery over three years in a 308 ha freshwater tidal wetland on the Hudson River, NY. A glyphosate-based herbicide with an aquatic-approved surfactant was applied to the stands in September 2010 with follow-up spot applications annually. Phragmites stem density and herbaceous plant cover were estimated pre- and post-treatment within stands and compared to reference plant communities 610 m surrounding the stands. Before treatment, the three largest stands (0.300.75 ha) had significantly higher Phragmites cover and lower native plant cover than the two smallest stands (0.04 ha). One year post-treatment, Phragmites stem density and cover were reduced by >85% in all five stands, and native plant cover significantly declined in the two smallest stands. By Year 2, native plant cover had significantly increased compared to pre-treatment data in all but one stand. However, native plant composition in the three largest stands was significantly different from the surrounding plant community, with a high

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abundance of early successional species, while the composition of the two smallest stands was similar to the surrounding wetland. Both pre-treatment Phragmites stand size and native plant cover strongly influenced native plant recovery and should be factored into management decisions. Questions and Answers Q: What is an invasive versus native plant species? A: Prefer using native versus non-native species terminology. Phragmites has been here for an estimated 200 years. The yardstick for considering a species non-native is often 500 years. This is an arbitrary number and not necessarily meaningful. Q: Has Phragmites been able to colonize because of pollution? A: Many external factors, including pollution, may have facilitated colonization (e.g., muskrat decline). The expansion of Phragmites may also be a result of its inherent ability to outcompete other species. Invasiveness of the species versus invasibility of the environment we dont know which is the primary driver. Q: Will loss of Phragmites and recolonization by native species survive the pollution? A: Pollution tolerance varies by species. Some native species are more tolerant than others. There is some evidence that Spartina species are sensitive to nitrogen pollution. Q: Was increasing the number of marsh channels a result of erosion of the marsh surface? If so, did you track where the sediment ended up? A: We did not specifically track sediment movement. Q: Did you measure subsidence of the marshes in the Delaware Estuary? A: No. Q: Have you thought about harvesting Phragmites for fuel pellets rather than just flattening it? A: We originally cut Phragmites before covering with geotextile but the sharp ends of the cut stems punctured the fabric. Q: What are the impacts of geotextiles on fish? A: None no fish are trapped under the geotextiles when it is installed. The geotextile may kill soil organisms. Q: How long does it take for native species to recolonize an area after Phragmites has been eliminated? Sedimentation rates and wave attenuation would be affected during the revegetation period. A: One hundred percent plant cover is restored within two growing seasons. Q: Ramshorn Marsh and Constitution Marsh are not like Piermont. They are dominated with native species and only have small patches of Phragmites. Piermont is dominated with Phragmites and only has small patches of native species. How is the management at Ramshorn and Constitution relevant for Piermont? A: Some of the same Phragmites management techniques could be used on Piermont. Q: Why is there so little Phragmites at Ramshorn Marsh and Constitution Marsh?

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A: We dont know may be influenced by many factors including: land-use history, seed availability, dispersal vectors, native community invasibility, etc. Q: Is Phragmites eradication possible? A: If Phragmites is well established in the system, management should focus on maintaining Phragmites-free zones or reducing the overall density. Continuing maintenance is required. Q: Given that the World Health Organization has declared glyphosate a probable carcinogen, do you have any reservations about using it for marsh management? A: No the wetland approved herbicide is applied by licensed applicators. Management is designed to minimize the use of herbicide. We will continue to monitor for non-target impacts and better understand the ultimate fate of glyphosate in the environment. Q: For months you and others have repeatedly said that there is no plan. When will you provide a written plan that can be critiqued? A: Summer 2015 Q: Is a NEPA Environmental Impact Statement needed for the project? A: No all the necessary permits are in place to conduct marsh vegetation management. Additional permits may be necessary if alternative projects (e.g., marsh creation or expansion) are selected. Q: Will the public be a part of the planning process? A: Yes this will not be the last time we will meet. A draft management plan will be presented to the community. The community will have an opportunity to review and comment on the plan. We will consider public desire for sitting at the table as management options are developed and refined. Comments Recent data from all marshes in the Hudson River show the highest levels of nitrogen in a

long time. Phragmites arrived in the Hudson River during the 20th century. Based on pre-Columbian

fossils, there was historically very little of it in the Hudson River. Birds do not die when their habitat is lost, they just relocate. Money would be better spent elsewhere since Phragmites invasion is so far along at

Piermont. Positive mitigation proposals include: 1) creating new marsh islands; 2) creating oyster reefs; and 3) adding marsh along the river edge.

Iona is pretty heavily invaded. Treated 10-acre area of Phragmites-dominated marsh in 2008. Now only three percent Phragmites cover. Treated areas are now covered in cattail. Have seen expansion of rare plants. Found that some of the marsh birds returned including Virginia rail and marsh wren.

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Feedback Forms (5 total): How much has this meeting increased your knowledge and understanding of the topics discussed today? A great deal: 2 A lot: 2 Some: 0 A little: 0 Not at all: 1

This meeting was a good use of my time: Strongly agree: 2 Agree: 2 Unsure: 0 Disagree: 0 Strongly disagree: 1

What was the most valuable information you heard here today? A lot of things for example: we expect to share with you at public meetings and were

going to talk to you about these things. Im not sure. I liked hearing about the use of textile to kill Phragmites/rhizomes with very localized use of

glyphosate. The effectiveness of herbicide. The careful application of herbicide to improve other growths. Piermont Marsh to be strongly affected. What worked well and what didnt? Some talk in terms of we versus you (the audience) wasnt helpful. Raised the question of

trust. The speakers were good, the audience was a bit rude. I appreciated the control and fluidity in asking questions. Good job! Limiting emotional outbursts from people fearing herbicides. Nothing. How could the format of the meeting be improved for future fact-finding meetings? Format was good. I dont know. Include local residents in decision-making. Have you attended a previous fact-finding meeting? Yes: 2 No: 3

Do you think you might attend the next fact-finding meeting? Yes: 4 Maybe: 1 No: 0

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Meeting 4: What do we know about methods of managing marsh vegetation?May 21, 2015, Piermont Village Hall, 6:00-8:30pm

Content:Summary of Presentations:Marsh management considerations: Betsy Blair, NYS Department of Environmental Conservation/Hudson River National Estuarine Research ReservePhragmites management techniques: Erik Kiviat, Hudsonia, Ltd.Restoration of Phragmites dominated marshes along the Delaware Estuary: Gary Bickle, AKRF, Inc.Phragmites control and restoration at Constitution Marsh: David Decker, Constitution Marsh Audubon Center & SanctuaryTrajectory of native plant recovery: management of five Phragmites australis stands in a Hudson River freshwater tidal marsh: Chris Zimmerman, The Nature Conservancy

Questions and AnswersFeedback Forms (5 total):_____________________________________________________________________________