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 Acknowledgements We would like to thank several parties for making this report possible. First, we would
like to thank Burlington Parks and Recreation, and especially our project sponsor, Dan Cahill.
Also, thank you to Cory Campbell of Burlington Parks and Recreation, for joining us in the field
and helping us to orient ourselves and identify problem areas.
We would also like to thank Donia Prince of The Nature Conservancy for educating the
LANDS crew about the causes and consequences of the non-native invasive species problem in
Vermont, and for her training on species identification and the iMapInvasives software. Thank
you to Liz Thompson for a lovely walk in Gleason Brook, and for her training in natural
communities classification.
LANDS work was also supported by the Conservation Leadership Seed Fund of the
Rubenstein School of Environment and Natural Resources at the University of Vermont (UVM).
The Student Conservation Association contributed administrative and program support,
oversight, time and financial resources. Finally, thanks to the GreenHouse Residential Learning
Community staff at UVM for lending us their great facilities.
About the LANDS College Sustainability Corps The field of conservation is rapidly evolving to meet our growing understanding of
ecological health and sustainability. New ideas and strategies are changing how we protect and
steward land. The Land Stewardship Program (LANDS) is a new approach to today’s
stewardship challenges. During the Great Depression, the conservation corps model was
pioneered as a means to promote nationwide stewardship and provide jobs for the unemployed.
That idea has since been reinvented numerous times by local and state corps across the United
States. However, the general theme is the same – young people learning and growing through
service. LANDS is a partnership between the University of Vermont and the Student
Conservation Association in its fifth year of service that operates as an innovative College
Sustainability Corps designed to train tomorrow’s conservationist practitioners and leaders.
Thanks to college level education and prior experience in environmental science fields,
LANDS interns are able to take on projects that are more technical than the work traditionally
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done by conservation corps crews. LANDS interns draft management plans; map areas of
interest using GPS and GIS; inventory resources; survey for non-native invasive species;
calculate carbon stocks; survey soils for forestry impact; and even find time to build trails and
perform public education and outreach. Municipalities, land trusts, state agencies, university
researchers, national forests and parks, and volunteer-managed conservation organizations all
benefit from LANDS’ high quality, affordable services. LANDS interns are advanced
undergraduates and recent graduates with natural resource experience from all over the world,
who bring a range of skills and interests to the program.
For more information, visit: http://www.uvm.edu/~conserve/lands_website/
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Table of Contents
Acknowledgements ......................................................................................................................... 2 About the LANDS College Sustainability Corps ........................................................................... 2 Burlington Parks & Recreation NNIS Mapping Project Overview ................................................ 5 Field Methodology ...................................................................................................................... 6 Overview of Parks........................................................................................................................... 7 McKenzie Park................................................................................................................................ 8 Overview ................................................................................................................................. 8 Natural Communities .............................................................................................................. 8 Summary ............................................................................................................................... 11 Arms Grant Property ..................................................................................................................... 12 Overview ............................................................................................................................... 12 Natural Communities ............................................................................................................ 12 Summary ............................................................................................................................... 14 Leddy Park .................................................................................................................................... 16 Overview ............................................................................................................................... 16 Natural Communities ............................................................................................................ 16 Summary ............................................................................................................................... 21 Ethan Allen Park ........................................................................................................................... 22 Overview ............................................................................................................................... 22 Natural Communities ............................................................................................................ 22 Summary ............................................................................................................................... 27 Mount Calvary Wetland ................................................................................................................ 28 Overview ............................................................................................................................... 28 Natural Communities ............................................................................................................ 28 Summary ............................................................................................................................... 30 Conclusion .................................................................................................................................... 30 Consequences of Invasive species ........................................................................................ 30 Recommendations & Management Priorities ....................................................................... 30 iMapInvasives Software........................................................................................................ 34 4
Burlington Parks & Recreation NNIS Mapping Project Overview The 2011 LANDS crew surveyed five properties owned and managed by Burlington
Parks and Recreation in order to take a thorough inventory of the non-native invasive plant
species (NNIS) present. At each of the properties - McKenzie Park, Arms Property, Leddy Park,
Ethan Allen Park, and Mouth Calvary Wetland—our team identified and determined relative
densities of NNIS present and gathered data about areas and patterns of infestations for each
species. Using GPS and GIS technology, we used this data to create detailed maps that reflect
our field observations.
We hope this information will facilitate management and removal of these plants, which
threaten the health of the field, forest, and wetland ecosystems in Burlington city parks. These
data also serves as a base for how the severity of the NNIS problem changes over time and
space.
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Field Methodology Over the course of one week, the LANDS team surveyed five Burlington city parks:
Ethan Allen Park, Leddy Park, McKenzie Park, Mount Calvary Wetland, and the Arms Grant
Property. Each park was divided into four quadrants based on trails and recognizable features, to
create easily identifiable boundaries by which our crew could survey the entirety of the park. The
nine LANDS interns were assigned to four teams, one for each quadrant. The quadrants were too
expansive to be exhaustibly inventoried, thus the teams used the most efficient methods to map
the park. Groups walked the plot boundaries and official trails and surveyed representative
transects in areas 50 meters or greater between trails.
When an invasive species was identified within a plot, the extent of the infestation was
determined and marked on a GPS unit. To mark a single plant or a small infestation, less than
five square meters, a single point was taken. For larger infestation areas, waypoints were taken
along the perimeter, sometimes spanning the entire area of the park and the frequency of
sightings was recorded. Team members then recorded on a data sheet (see appendix 1) the
species observed, GPS waypoint(s), landscape type, native vegetation, estimated area, cover
class, distribution, and maturity of the infestation. The data sheet was provided by the Nature
Conservancy, intended to be used with the iMapInvasives Inventory database. Notes were also
taken on general observations of the infestation.
LANDS interns comparing Norway maple and sugar maple growing side by side in Ethan Allen Park.
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Overview of Parks 7
McKenzie Park Overview McKenzie Park is a 65-acre area located behind the Intervale Center with 35% tillable
land and 65% wetland forest. The park is bordered by the Winooski River, as well as working
agricultural fields. McKenzie is accessible by the bike path and a dirt road. The park contains no
amenities or marked trails and does not show signs of high recreational use by visitors. There
was a higher density of invasive species found along the edges of the tillable land in comparison
to the wetland forested areas. The invasive species that were most abundant in this area include
large, dense patches of goutweed (Aegopodium podgraria), Japanese knotweed (Fallopia
japonica), common buckthorn (Rhamnus cathartica), honeysuckle (Lonicera sp.), Dame’s rocket
(Hesperis matronalis), and garlic mustard (Alliaria petiolata).
Ostrich fern (Matteuccia struthiopteris)
Natural Communities The McKenzie natural area is largely composed of a Silver Maple-Ostrich Fern Riverine
Floodplain Forest. This type of natural community is common along many of Vermont’s major
rivers. The area is annually flooded and has visible evidence of old channel meanders, levees,
and sediment deposits. The soil is rich, silty clay with no visible organic layer. The canopy is
largely dominated by silver maple (Acer saccharinum) with a smaller component of cottonwood
(Populus deltoides). Areas closer to the water have an understory of ostrich fern or sensitive fern.
Areas further from the river had no herbaceous vegetation present due to recent flooding.
Vernal pools are scattered throughout the McKenzie natural area. At the time of our visit,
these pools were clearly visible due to recent flooding. Vernal pools are small bodies of water
that occur in forest depressions and dry up seasonally. There is very little vegetation in and
around vernal pools; however, the pools are extremely important for a multitude of fauna. These
pools are considered the best-known habitat for amphibian breeding, due to their lack of
predators. In Vermont, many species are known to use vernal pools to mate and lay eggs in the
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early spring. These species include wood frog, spring peeper, spotted salamander, Jefferson’s
salamander, blue-spotted salamander, and red-spotted newt. (Thompson & Sorenson, 2005)
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Summary The McKenzie natural area was found to have nine invasive species within its borders.
Most of these species were found along the highly disturbed edges of the agricultural fields.
Dame’s rocket was the most abundant species along the field edges, followed by common
buckthorn. Along the western edge of the fields, there is an infestation of honeysuckle that
should be closely monitored since this species can spread quite rapidly, especially in a disturbed
area.
Along the riverbank, two invasive species were found: goutweed and Japanese knotweed.
These species were most likely introduced from seeds or cuttings that floated downstream since
there is a clear break between this infestation and the infestation along the fields. The goutweed
was found growing in dense, linear patches that runs parallel to the river. These patches would
otherwise be valuable riverside habitat for native species. It is recommended that these goutweed
infestations be removed before they spread further and impact the native vegetation beyond an
easily reversible point. Japanese knotweed was found as scattered individuals and loose clumps.
Even though the infestation of knotweed is relatively small, it is of great concern since this
species is known to quickly outcompete native vegetation resulting in an invasive monoculture.
To remove the knotweed, individuals should be located and cut just above the base, but not
uprooted. The cuttings should be carried out to avoid re-rooting.
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Arms Grant Property Overview The Arms Grant Property is an urban park located near Lake Champlain consisting of
30.5 acres of woodland. The park has an extensive network of trails, including some unofficial
trails. The park is bordered by residential areas, commercial areas, Burlington High School, and
a church complex. A high density of invasive species is found along these borders. The center of
the property is relatively clear of invasives with the exception of common buckthorn. The
predominant invasive species found in this park are common buckthorn (Rhamnus cathartica),
glossy buckthorn (Frangula alnus), honeysuckle (Lonicera sp.), Japanese barberry (Berberis
thunbergii), common barberry (Berberis vulgaris), and Norway maple (Acer platanoides).
Natural Communities There are two main natural communities that make up the Arms Grant Property: Mesic
Maple-Ash-Hickory-Oak Forest and Transition Hardwoods.
A Mesic Maple-Ash-Hickory-Oak Forest is the most prominent community at the Arms
Grant Property. This community type is typically dominated by red oak (Quercus rubra), white
oak (Quercus alba), red maple (Acer rubrum), sugar maple (Acer saccharum), eastern hemlock
(Tsuga canadensis), white pine (Pinus strobus), paper birch (Betula papyrifera), shagbark
hickory (Carya ovata), hophornbeam (Ostra virginiana), white ash (Fraxinus Americana), and
basswood (Tillia americana). This community type can harbor thirteen rare and uncommon
plants including pignut hickory (Carya glabra), flowering dogwood (Cornus florida), and roundleaved tick trefoil (Desmodium rotundifolium). This forest community provides habitat for many
mammals including white-tailed deer, white-footed mouse, woodland jumping mouse and
chipmunks. Songbirds such as the eastern wood pewee, red-eyed vireo, ovenbird, and blackthroated blue warbler nest here.
A Transition Hardwood Forest is defined by the calcium-rich bedrock and shallow,
enriched soils. These conditions allow for the occurrence of a rare forest type with shagbark
hickory, and a rich herbaceous layer with wide-leaved sedge (Carex plantaginea), early meadow
rue (Thalictrum dioicum), blunt-lobed hepatica (Hepatica americana), yellow lady slipper
(Cyripedium calceolus var. pubescens), and stout goldenrod (Solidago squarrosa). There are also a number of wetlands scattered throughout the forest that provide valuable
habitat for amphibians. Vernal pools create crucial breeding habitat for spotted salamanders,
wood frogs, and spring peepers. Seeps and shrub swamps also dot the landscape, creating
microclimates for red maple and sensitive fern (Onoclea sensibilis) in the former, and speckled
alder (Alnus rugosa), silky dogwood (Cornus amomum), skunk-cabbage (Symplocarpus
foetidus), and clearweed (Pilea pumila) in the latter.
(Thompson & Sorenson, 2005)
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Summary The Arms Property was found to have fourteen invasive species present. The infestations
are not extremely dense here, but are rather scattered across the property. The diversity in
invasive species present is alarming. Common horticultural species are often considered invasive
as soon as they enter into a natural community. The suburban context of the Arms Property has
probably contributed to the introduction of this multitude of invasive species through
landscaping practices. The northeastern boundary of the property is of particular concern since it
is densely packed with Norway maple and honeysuckle, both rather aggressive invasive species.
The church that neighbors the Arms Property to the northeast has planted Norway maple across
their entire property, which seems to be the source of the dense infestation on the Arms property.
Removing the Norway maples along this edge of the property would prevent the infestation from
moving deeper into the forest, since this is near a strong seed source.
Common buckthorn (Rhamnus cathartica)
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Leddy Park Overview Leddy Park is a 65-acre waterfront park on Lake Champlain, heavily used for recreation.
It is 65% woodland, 15% mowed land, and 20% facilities, parking lots, and court surfaces. The
park is located in an urban area surrounded by residential and commercial development. The
park contains 1,800 feet of lakefront property including a sandy beach. It has a wide variety of
outdoor amenities, as well as indoor facilities including restrooms and an ice arena. Leddy Park
is accessible by bike path and by car. The park attracts many visitors seasonally.
The most abundant invasive species found in Leddy Park include common and glossy
buckthorn, oriental bittersweet (Celastrus orbiculatus), Norway maple, garlic mustard, bush
honeysuckle, and multiflora rose (Rosa multiflora). A high density of invasive species was found
along property boundaries, power lines, forest
or trail edges and other disturbed areas.
Natural Communities Leddy Park is highly disturbed with
many human-managed areas and invasive
plants. The natural areas that remain can be
classified as a Mesic Red Oak-Northern
Hardwood Forest. This natural community
type is dominated by red oak, sugar maple, and
American beech (Fagus grandifolia), with
scattered white ash, basswood (Tilia
americana), butternut (Juglans cinera), eastern
hemlock, and sweet birch (Betula lenta). This
community could host up to eight rare and
uncommon plants including squawroot
(Conopholis americana), Minnesota sedge
(Carex albursina), and ginseng (Panax
quinquefolius).
(Thompson & Sorenson, 2005)
Asiatic bittersweet (Celastrus orbiculatus) at Leddy Park
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Summary Thirteen non-native invasive species were found within Leddy Park. The eastern portion
contains thirteen different species, while the western portion contains only nine. The infestation
is very extensive in this park, especially along the edges of landscaped or highly altered areas of
the park. Norway maple is very abundant in the forest canopy in most of the park, excluding the
southwest corner. There was one invasive plant, Japanese barberry, found in a planted garden
next to the ice rink. We would suggest more careful selection of landscaping species if the city
wishes to minimize the impact of invasives in Leddy Park.
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Ethan Allen Park Overview Ethan Allen Park is a public, natural area that spans over 85 acres. It is 80% woodland,
10% trail and 10% mowed areas. The park is in close proximity to North Avenue, the Winooski
River and residential developments. It contains many trails with one main paved trail. The park
is also home to the Ethan Allen Tower, a culturally valued historic site.
Natural Communities The park’s vegetation falls into
three main natural community types:
Mesic Oak-Hickory-Northern Hardwood
Forest, Dry-Oak-Hickory-Hophornbeam
Forest, and Temperate Calcareous Cliff
Community.
A Mesic Oak-Hickory-Northern
Hardwood Forest should be dominated
by red oak, sugar maple, basswood,
beech, and hemlock. This community
type could harbor eight rare and
uncommon plants including squawroot
(Conopholis americana), Minnesota
sedge (Carex albursina), and ginseng
(Panaz quinquefolius).
A Dry-Oak-HickoryHophornbeam Forest should be
dominated by red oak, hophornbeam, and
shagbark hickory, with a smaller
component of white oak, sugar maple, and white ash. This community type may also harbor
fourteen rare and uncommon plants including yellow oak (Quercus muehlenbergii), four-leaved
milkweed (Asclepias quadrifolia), and wood lily (Lilium philadelphicum). These forests provide
habitat for white-tailed deer, white-breasted nuthatch, scarlet tanager, and wild turkey.
A Temperate Calcareous Cliff community should be dominated by northern white cedar
(Thuja occidentalis), white ash, eastern red cedar (Juniperus virginiana), and hophornbeam. This
community type typically harbors thirteen rare and uncommon plants including wall-rue
(Asplenium rutamuraria), Steller’s cliff brake (Cryptogramma stelleri), and smooth cliff brake
(Pellaea glabella). These forests provide nesting habitat for turkey vultures and sunning ledges
for many different species of snake.
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Summary Eleven invasive species were found in Ethan Allen Park, ten in the northern half and
eleven in the southern. The forest canopy here is dominated by Norway maple, which is
outcompeting all the native tree species. Dense infestations of Japanese knotweed and garlic
mustard can be found along the road that borders the park to the west. Common buckthorn and
honeysuckle were quite abundant throughout the park. The suburban location of Ethan Allen
Park makes complete eradication difficult since a seed bank of invasives exists around all edges
of the park. Just across Ethan Allen Parkway, goutweed and Japanese barberry are being used as
landscaping plants.
Rock outcrop at Ethan Allen Park
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Mount Calvary Wetland Overview Mount Calvary Wetland is a natural area that spans 12.2 acres and consists of 100%
wooded wetland. The area is completely surrounded by residential development with fencing to
designate its borders. This area is not desirable for recreational use due to saturated soils and is
not heavily colonized by invasive species.
Natural Communities The Mount Calvary natural area is categorized as a Red Maple Wetland with two natural
communities present: a White Pine-Red Oak-Black Oak Forest and a rare Sandplain Swamp
variant of the Red Maple Sphagnum Acidic Basin Swamp natural community (Thompson &
Sorenson, 2005).
A White Pine-Red Oak-Black Oak Forest is present in the northern portion of the site.
This community is uncommon in Vermont, found only in the warmest climate areas with shallow
bedrock (Thompson & Sorenson, 2005). This community has a forest canopy composed
primarily of white pine (Pinus strobus), red maple, red oak, and black oak (Quercus velutina).
This community is poorly understood since there are no known undisturbed examples of it. The
shrub layer generally contains a mixture of witch hazel (Hamamelis sp.), smooth shadbush
(Amelanchier laevis), and low shrubs of the heath family. Overall, plant diversity is low and
herbs are practically absent (Thompson & Sorenson, 2005).
The larger component of the Red Maple Wetland site is characterized by a Sandplain
Swamp variant of the Red Maple Sphagnum Acidic Basin Swamp natural community
(Thompson & Sorenson, 2005). Local and state municipalities consider this land significant since
it has only been identified at four other locations in Vermont. The area has a seasonally high
water table due to sandy soils above a layer of silt or clay that seals off drainage (Coven %
Severson, 2005). At the time of our visit, some areas of the parcel were overlain by up to 20
inches of standing water due to recent, record-breaking flooding. The tree canopy is dominated
by red maple. The shrub layer was composed primarily of ferns with some blueberries and
winterberries mixed in. Several sphagnum species were present as well.
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Summary Mount Cavalry Wetland is barely colonized by invasive species. The only two invasive
species that were found in this area were Norway maple and glossy buckthorn. Only a single
glossy buckthorn plant was found on this site. The Norway maple was confined to a small strip
along the northwest boundary. Of all the parks we mapped, Mount Calvary Wetland was the
least impacted by non-native invasive species.
Conclusion Consequences of Invasive species Invasive species impinge on the ecological benefits and human enjoyment of the parks;
therefore it is important to address the problem of invasive species before they decrease the value
of our park system. The current populations of invasive species in Leddy Park, Ethan Allen Park,
McKenzie Park and Arms Grant Property are thriving and slowly transforming the vigor of
ecosystem services provided by the native flora and fauna. We recommend that the city prioritize
the parks with high ecological value and minimal invasive species before initiating the long-term
removal methods for the heavily populated parks.
Recommendations & Management Priorities Three criteria were considered to determine the management priorities:
 Ecological impact and value of ecosystem functions
 Magnitude of infestations
 Feasibility of removal
High Priority Mount Calvary Wetland: Mount Calvary hosts a rare wetland ecosystem only found in four other locations in Vermont. It
provides critical habitat for the plants and animals that live in the wetland, as well as ecosystem
services for floodwater and sediment attenuation and storage. The area is surrounded on all sides
by residential development; as a result, the area is at high risk for invasive plant infestation. At
this time, the level of invasive species infestation is minimal and could be easily controlled if
addressed quickly and monitored over time.
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Recommendations:
We recommend the immediate removal of the few scattered invasives in order to address the
problem before it spreads out of control. There is also a significant amount of refuse in the area,
some dumped over the fences of the surrounding homes. We recommend that Burlington Parks
and Recreation initiate community education with the neighborhood and erect signage to discuss
Mount Calvary’s ecological importance.
McKenzie Park: McKenzie Park provides crucial ecosystem services such as flood mitigation, erosion control,
and improved water quality. The invasive species present in the park have shallower root
systems than our native plants, promoting soil erosion. If invasive species are allowed to take
over the park the ecosystem, services provided by the area will be degraded.
Recommendations:
Our recommendation for this site is to remove the invasive species on the Winooski River bank
and replant native tree species to restore a healthy riparian zone and prevent further soil erosion.
The Japanese knotweed should be cut down once a year for four years to control, and eventually
kill, the infestation. The herbaceous invasives, such as goutweed, grow in large, dense patches,
outcompeting native species and minimizing diversity. If possible they should be managed to
improve the ecosystem health of the area. Common buckthorn is found throughout the park and
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total eradication may not be possible, however any level of removal and control of new growth
will limit spread.
Arms Grant Property The rich soils in this site create a habitat for many rare plant species. The area also encourages
biodiversity through its diverse range of habitat. Management and control should be
implemented to maintain and restore these natural communities wherever they are threatened by
currently present or adjacent invasive species infestations.
Recommendations:
The Japanese knotweed, goutweed and Norway maple in this area seem to be the most feasible
target species for removal. There is an extensive infestation of buckthorn throughout the area that
ranges from young to mature. A long-term removal and control project should be considered for
this type of infestation. The Japanese knotweed and goutweed are found only on the periphery of
the park and should be promptly addressed to prevent spread inside the park.
Medium Priority Leddy Park This park is highly infested with invasive species,
thus it will be difficult to restore the park to its natural
state. If the invasives in this park are not managed,
however, they will provide a seed bank, allowing the
further spread of invasives into other natural areas.
Recommendations:
We recommend that Parks & Rec focus on preventing
monocultures of invasive species from taking over the
park. Barberry, goutweed, bittersweet and other
species have the potential to take over a landscape,
decreasing the recreational value and degrading the
natural communities.
Ethan Allen Park Ethan Allen is a diverse and engaging landscape that
is enjoyed by many Burlington residents and
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Ethan Allen Park (note winged burningbush)
inhabited by many floral and faunal species. There are numerous invasive species in the park, but
the infestation can still be managed to preserve the integrity of the park.
Recommendations:
A long-term management plan for this park needs to be developed to ensure an effective strategy
to control the invasive species. Eradication of those species that are not yet firmly established in
the park should be the first priority, followed by efforts to control those species that infest the
ecosystem.
Works Cited Coven, L. & Severson, J. (2005). Mount Calvary Red Maple Wetland: A Burlington Natural
Area Management Plan.
Thompson, E. & Sorenson, E. (2005). Wetland, Woodland, Wildland: A Guide to the Natural
Communities of Vermont. Lebanon, NH: The Nature Conservancy and the Vermont Department
of Fish and Wildlife.
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iMapInvasives Software http://www.imapinvasives.org/vtimi
The Nature Conservancy is piloting iMapInvasives (iMap), an online, GIS-based
mapping tool for the collection and display of invasive species location data from multiple
sources. This website is anticipated to become an application on smart phones in the near future
if the technique is deemed efficient and useful for field surveys of nonnative invasive species.
The benefits of this easy access website are that it is user-friendly, provides an easy method for
adding attributes while entering data (with drop down menus), and it allows for public as well as
professional use. This wide variety of users will provide a link between research and citizen
observation. Additionally, statewide sharing of information is made possible through this
program and provides early detection and rapid response efforts through e-mail alerts sent from
iMap.
The LANDS program partnered with the Nature Conservancy to conduct a trial run for
entering invasive species information into iMap with data collected during the Burlington Parks
and Recreation project. However, the LANDS team encountered several problems with the
program, which dissuaded us from using it at the time. The field challenges included
incompatibility with GIS software, which was time consuming since GPS waypoints could not
be uploaded directly into iMap. Also, there is no scale bar for the maps in iMap, which causes
inaccuracy when creating polygons. An additional problem is that shape files cannot be imported
into iMap from GIS software.
The LANDS program is happy and willing to promote the use of iMap by using the
program for future invasive species surveys if the current problems can be resolved. We hope
that our recommendations will aid in the revision of a new and improved iMap version for more
successful and efficient usage of this powerful tool.
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