Virginia Coastal Program: 2002 Coastal Grant Project Description and Final Summary
Project Task:
FY2002 Task 12.05
Grantee:
Virginia Department of Conservation and Recreation
Project Title:
Virginia Seaside Heritage Program: Mapping and Threat Assessment of Phragmites
Project Description as Proposed:
Nationwide, invasive
species have been identified as the Number Two threat to biological
diversity, second only to loss of species and habitat from development
and urban sprawl. The invasive wetland grass known as common reed
(Phragmites australis), hereafter called “Phragmites”,
is one of our most serious and problematic invasive plant species.
Phragmites is found in every U.S. state and is well-established
and increasing in coastal habitats of Virginia. This fast-spreading
plant grows up to 4 meters tall and forms dense monotypic stands,
crowding out other native marsh plants. Phragmites is long-lived
and spreads rapidly due to its ability to reproduce both by seed
and dispersed rhizome fragments, establishing readily in disturbed
areas. As a result, marsh plant species diversity and habitat quality
is drastically reduced for many kinds of marsh-dependant wildlife.
Phragmites is now known to exist in North America, including Virginia,
in two genotypic forms. One form is native to the U.S. and appears
to have been a non-dominant component of diverse eastern seaboard
marsh communities for millennia. Recent DNA studies provide strong
evidence that a distinct, non-native Phragmites genotype is also
present in the U.S., supporting the existing theory that an introduced
variety of Phragmites has been aggressively invading and dominating
coastal marshes and other wetland communities, in part due to a
lack of natural biological control mechanisms. The presence of an
invasive, non-native form of Phragmites largely explains how and
why the plant has rapidly spread and become dominant over thousands
of acres of wetland communities during the last two decades in the
Northeast and mid-Atlantic regions.
The Virginia portion of the Chesapeake Bay as well as the extensive
estuarine and island wetlands of the Eastern Shore Seaside are now
“on the cusp” of a non-native Phragmites invasion. Further,
a lightning-ignited wildfire on the soon-to-be dedicated Parramore
Island Natural Area Preserve (NAP) has raised concern that existing
Phragmites patches there will expand rapidly in the post-fire disturbance
environment. With immediate control efforts on Parramore Island
NAP and other high priority locations, wetlands on the Seaside may
be spared the near-total colonization by Phragmites witnessed in
many coastal areas just northward.
The work proposed here will: 1) assess the current extent of Phragmites
on the Seaside of the Virginia Eastern Shore, 2) produce maps displaying
Phragmites occurrences and adjacent or nearby significant occurrences
of rare species, critical wildlife habitats, and exemplary natural
communities, 3) develop a threat assessment giving prioritized recommendations
for Phragmites patch control on Parramore Island, 4) produce a report
describing the response of Phragmites to the recent wildfire on
Parramore Island, and 5) describe methods for monitoring the response
of Phragmites to control treatments.
A separate Seaside Heritage project to be conducted by the Eastern
Shore Field Office of The Nature Conservancy will begin implementing
control measures for high priority patches of non-native invasive
Phragmites on Parramore Island, as well as other key Seaside locations
held in the public interest.
Federal Funding:
$47,910
Project Contact:
Richard K Myers, (804) 371-6204, rkmyers@dcr.state.va.us
Project Status:
Grant Closed
Final Product Received:
A
Final Report for this Seaside Heritage Program component may be
cited as follows and copies available from DCR-Division of Natural
Heritage:
Myers, R.K., J.T. Weber, P.P. Coulling, D.R. Young, A. Belden, A.C.
Chazal, K.E. Heffernan, and C.J. Hutto. 2003. Mapping and threat
assessment of Phragmites on the Seaside of Virginia's Eastern Shore.
Virginia Department of Conservation and Recreation, Division of
Natural Heritage, Richmond, Virginia. Final report for Year One
of the Seaside Heritage Program submitted to USDC National Oceanic
and Atmospheric Administration. Natural Heritage Technical Report
#03-19, November 2003. 50 pp. + appendices.
Project Summary Provided by Grantee:
Project
Scope: Year One of this project to map and assess threats posed
by Phragmites on the Seaside had the objectives of:
1. Assessing the current extent of Phragmites on the Seaside of
the Virginia Eastern Shore and developing maps displaying Phragmites
occurrences and adjacent or nearby significant occurrences of rare
species, critical wildlife habitats, and exemplary natural communities;
2. Conducting a threats assessment, allowing prioritized control
of Phragmites patches on Parramore Island;
3. Assessing the response of Phragmites to the recent wildfire on
Parramore Island;
4. Monitoring the response of Phragmites to control treatments initiated
in late summer of 2003.
Results:
1. Maps of the current Seaside Phragmites invasion were produced
from data sources including digitized aerial video images and hyperspectral
data. Combined with new GPS data acquired from helicopter- and ground-mapping,
this map portrays current Phragmites patch locations and highlights
where Phragmites occurrence coincides with land and water areas
in the public interest. A second map was produced for Parramore
Island based on ground-based GPS mapping of Phragmites patches,
portraying the extent of Phragmites colonization after the September
2002 wildfire and prior to any control treatments. A total of 58
Phragmites patches were mapped, covering an area of 112 acres.
2. Threats posed by the current invasion of Phragmites on Parramore
Island were assessed. Data were collected using GPS technology and
mapped to document exact locations of Natural Heritage Resources
and to assess their spatial relationship to Phragmites patches.
"Fresh" marshes dominated by Spartina patens or Panicum
dichotomiflorum, as reported in 1976 were not found in this project
and may now be dominated almost exclusively by Phragmites, suggesting
Phragmites has eliminated a pre-existing natural community on Parramore
Island. A rare plant, Fimbristylis caroliniana (Carolina fimbry),
was found on the Island and could be threatened by Phragmites if
those stands expand. No rare animal species were found.
3. Phragmites response to disturbance by wildfire on Parramore Island
was assessed and quantitative descriptions of change in Phragmites
patch size, rates of spread, and threats to adjacent natural vegetation
following the September 2002 wildfire were made. Phragmites cover
on Parramore Island has increased rapidly in recent years. Satellite
images indicated approximately 26 ha of Phragmites present in 1999,
while ground-mapping in 2003 identified 87 ha of Phragmites present
- an increase of 230% in four years. Following the 2002 wildfire,
17 patches of Phragmites were identified within the fire zone ranging
from 0.1 ha up to 25 ha with total Phragmites cover about 32 ha,
23% greater than Phragmites cover over the entire island in 1999.
4. Monitoring systems were established to measure Phragmites spread
and evaluate effectiveness of control treatments. All monitored
Phragmites patches were assessed for native vs. non-native genotype,
species composition, stem height, stem density, patch size, and
adjacent vegetation. Patch markers were installed, photomonitoring
stations were monumented and pre-treatment photos taken, and GPS
positions were collected to facilitate re-measurements and treatment
applications. A related component of the Year One Seaside Heritage
Phragmites project involved plans by The Nature Conservancy to contract
aerial Phragmites control treatments on Parramore Island. In early
September, aerial herbicide application had been contracted with
a private vendor who was preparing to apply initial control treatments
to 100 ac of Phragmites mapped on Parramore Island. However, Hurricane
Isabel's winds and salt spray on September 18, 2003 caused top-kill
(premature vegetative senescence) in nearly all Phragmites stands
on the Eastern Shore, preventing all control applications planned
for Year One.
Form C end
Disclaimer: This project summary provides the federal dollars initially awarded to the grantee. Due to underexpenditure or reprogramming of grant funds, this figure may change. For more information on the allocation of coastal grant funds, please contact Laura McKay, Virginia Coastal Program Manager, at 804.698.4323 or email: Laura.McKay@deq.virginia.gov
A more detailed Scope of Work for this project is available. Please direct your request for a copy to Virginia.Witmer@deq.virginia.gov
