● The monoculture created by Phragmites australis limits the biodiversity of the Piermont Marsh ecosystem.

● Many have come to embrace the aesthetics and perceived benefits of the invasive plant and the local community is divided on the use of herbicide.

● Photo-deprivation methods used to isolate and eradicate P. australis in Constitution Marsh were applied in Piermont Marsh.

● After measuring the existing flora, a 25m x 19.8m stand of P. australis was flattened and then covered with black plastic geotextile material.

● After two growing seasons, an 11m x 5.8m area in the middle of the plot will be uncovered and closely monitored to identify native marsh plant succession.

● The size of the plot will be expanded 7m every two growing seasons.

● A 7m buffer of rhizome killing geotextile will be maintained between untreated and untreated areas of the marsh.

● Herbicide will be hand-applied on individual shoots of emergent P. australis when they appear.

● 2015 Plot - GPS coordinates were not accurate enough to measure a true rectangular plot, so the team resorted to an aerial measurement technique using long poles, precisely measured lengths of string, and the Pythagorean Theorem to establish the boundaries. The Phrag Stompers™ the team was able to quickly and efficiently clear the entire plot in less than a day. The staple method modeled by the Constitution Marsh team worked as expected and the plot was covered in a timely manner. Using GPS receivers to accurately measure ground elevation and the precise location of plot corners and transect endpoints was problematic. The GPS receivers were unable to produce reliable, consistent data, so a different method of elevation measurement will be needed for future plots.

Abstract Results

Methods● Potential plot sites were evaluated based on ease of

accessibility, lack of biodiversity, existence of active nesting, and precisely relocated using GPS

● Using precisely measured lengths of string held above the 5m tall P. australis stand using long PVC poles, and the Pythagorean Theorem, a rectangular plot was established.

● A 30m transect bisecting the plot was established and estimations of the flora were recorded for each meter quad along it.

● Ledger poles were constructed using PVC. The height of the culm base, new green growth, and shoots of the previous season’s dead P. australis were recorded in decimeter increments. Ground elevation were determined using GPS.

● Methods used to create crop circles were employed to crush the existing stand of P. australis.

● Six 25m x 3.8m sheets of the geotextile were applied over the crushed P. australis using a 0.6m overlap along the edges.

● 225 wire staples, made of 9 gauge galvanized bailing wire, were pushed through the geotextile and used to hook the existing underground rhizosphere in order to secure the sheets of covering to the ground.

● A 6m x 6m plot previously covered with black plastic in 2014 was re-covered with geotextile to be used for plant succession studies in 2016.

Eco-Friendly Habitat Restoration: Using Photo-Deprivation to Eradicate Phragmites australis and to Promote Native Plant Succession in Piermont Marsh, New York

By John Bjornton, Alondra Cruz, Brian Delgado, Shanon Dempster, Marc Jimenez, Bing Liang, Keylen Lucero, Debra Magadini, Anjelle Martinez, Andrew Mittiga, Julissa Nuñez, Raquel Peñalo, Stephanie Valentin, and Adam Viruet

● Funded provided by the Secondary School Field Research Program, the Young Women’s Leadership Network, the National Science Foundation, and the Pinkerton Foundation.

● Dr. Dorothy Peteet, Adjunct Senior Research Scientist at the LDEO Biology and Paleo Environment department, for invaluable help and guidance.

● Dr. Robert Newton and Susan Vincent, from SSFRP, for their constant support and scientific vision.

● Bill Herguth, Paradise Boats, for his considerable marsh wisdom and historical knowledge.

● David Decker, Land Steward for the Audubon Constitution Marsh Center & Sanctuary, and his crew for an authentic, functional vision of marsh remediation.

● Liz Pratusevich, Melody Henry, Lavern Cash, and Nancy Ramirez, who in past summers helped to lay the groundwork for the project.

Acknowledgments

Next Steps

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Because of the two year time period required to eradicate the existing rhizosphere and the ongoing management required to halt any subsequent P. australis incursion, it is necessary to track the results of this project for several years.● 2016 - The 6m quad covered in 2014 will be uncovered

and the succession of new plant growth will be closely monitored and measured to help predict native plant succession in the larger plots. After performing an aerial survey using a drone, a new 25m x 19.8m plot will be established close to the 2015 plot so they can eventually be joined together. Measurements of biodiversity and the existing flora will be recorded from both large plots using proper data protocol.

● 2017 - The middle of the 2015 plot will be uncovered and the existing 7m geotextile buffer will be expanded outward into the existing P. australis stand using this summer’s methods. Precise measurements will be recorded of new plant growth in the treated portion of the plot and lessons learned from observing plant succession in the 2014 plot will be employed to maximize native plant growth. A new 25m x 19.8m plot will be established nearby and measurements of the flora along all three transects will be recorded.

● Ultimately, a 7m band of P. australis will be left along the riverbanks to help stabilize them, and a 7m buffer of geotextile will be maintained inland between the P. australis border and the interior or the marsh where the native species of marsh plants will thrive.

● A management plan for maintaining the geotextile buffer and remediating against P. australis incursion using hand-applied herbicide will help prevent reinvasion.

● Quad Data - Using an estimation strategy modeled at Constitution Marsh, data representing percent coverage of different plant species for each square meter along the 30m transect were recorded. Due to inconsistencies in measurement protocol, the team was unable to reliably index the data from each quad to a specific location on the transect. A baseline for overall coverages of the quads adjacent to the transect were able to be calculated. In the future, the measuring tape used to index quad locations will be posted in a more robust, and precise manner.

● 2014 Plot - The black plastic covering the 6m quad had become brittle and needed to be replaced with the more durable geotextile material. No plant growth was observed in the plot and the residual dead plant matter was in an advanced state of decomposition. There appeared to be more groundwater present under the plastic, which indicates a subsidence of the surface level due to a reduction in the rhizosphere.

Height measurements of the base culm, green growth, and the previous year’s dead P. australis. Measurements along every 10cm established a baseline that was utilized for future growth comparisons. The following stacked line graph graphically illustrates a plot cross-section.

2015 photo deprivation plot

2014 photo deprivation plot

2015 1-meter quadrant