This document describes a project to eradicate the invasive plant Phragmites australis in Piermont Marsh, New York using photo-deprivation methods. Researchers established plots covered with black plastic geotextile to smother the P. australis stands. Monitoring of plant succession in uncovered areas of the plots aims to promote the growth of native marsh plants. The size of the treated plots and buffer zones will gradually expand over multiple growing seasons to restore the marsh ecosystem and limit further P. australis spread.

1. ● 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