Habitat & Management Practices |
|
Grasslands
Approximately 1,800 acres of the
Refuge is grassland and old field. Cooperative farmers hay and graze approximately
500 acres of cool season grasslands. These grasslands are dominated by orchard
grass (Dactylis glomerata), timothy (Phleum pratense), Kentucky bluegrass
(Poa pratensis), smooth brome (Bromus inermis), and reed canary-grass. Refuge
staff planted a diverse mix of warm season grasses on 55 acres. These grasses
include big bluestem (Andropogon gerardii), little bluestem (Schizachyruim
scoparium), Indian grass (Sorghastrum nutans), and switchgrass (Panicum virgatum).
Most fields are in the oldfield stage of succession and are composed of a
wide diversity of broadleaf plants, including goldenrods (Solidago spp.),
asters (Aster spp.), common milkweed (Asclepias syriaca), Canada thistle (Cirsium
arvense), wild bergamot (Monarda fistulosa), ox-eye daisy (Chrysanthemum leucanthemum),
and common mullein (Verbascum thapsus).
 |
| Wallkill River Valley |
To
date, 57 acres of former corn field were seeded with native warm season grasses.
Additionally, 40 acres of old agricultural field were burned in 2002. The objective
with both project is to restore natural grassland conditions to support nesting
for grassland dependent birds.
The
refuge is currently participating in a region-wide Grassland Breeding Bird Habitat
Management Study. The purpose of the study is to: 1) assess the grassland breeding
bird use, and vegetation structure or composition of managed grasslands on refuges;
2) evaluate the effects of current grassland management techniques; and 3) assist
in determining our Regional contribution to grassland breeding birds. Results
from this project, in coordination with the recommendations of the Regional
Grassland Bird Working Group, will help us to concentrate resources for grassland
birds where it makes the most sense. This project will also assist managers
in improving management techniques to create specific grassland vegetative for
specific breeding grassland birds.
<top of page>
|
Upland Forests
Eight-hundred acres of the Refuge
are deciduous hardwood forest. The most frequently seen common tree species
include: white oak (Quercus alba), chestnut oak (Q. prinus), red oak (Q. rubra),
black oak (Q. velutina), pignut hickory (Carya glabra), shagbark hickory (C.arya
ovata), red maple, sugar maple (Acer saccharum), white ash (Fraxinus americana),
tulip tree (Liriodendron tulipifera), black cherry (Prunus serotina) , yellow
birch (Betula alleghaniensis), black birch (B. lenta), flowering dogwood (Cornus
florida), sassafras (Sassafras albidum), hemlock (Tsuga canadensis), and eastern
red cedar (Juniperus virginiana). Common shrubs include maple-leaf viburnum
(Viburnum acerifolium), Japanese barberry (Berberis thunbergii), witchhazel
(Hamamelis virginiana), black-haw (Viburnum prunifolium) and spicebush. Mayapple
(Podophyllum peltatum), wild ginger (Asarum canadense), garlic mustard, New
York fern (Thelypteris noveboracensis), Christmas fern (Polystichum acrostichoides),
marginal wood fern (Dryopteris marginalis), and bracken (Pteridium aquilinum)
are common herbaceous plants.
<top of page>
|
Upland Shrublands
Shrublands comprise approximately
400 acres of the Refuge. These areas are intermediate in successional stage
between fields and forests. Common shrub species include gray dogwood (Cornus
racemosa), multiflora rose, eastern red cedar, and staghorn sumac (Rhus typhina).
Pioneer tree species such as quaking aspen (Populus tremuloides) and gray
birch (Betula populifolia) are also an important component of Refuge shrublands.
<top of page>
|
Wetlands
About 1,500 acres of the Refuge
is forested wetland. Characteristic tree species include red maple (Acer
rubrum), silver maple (A. saccharinum),box-elder (A. negundo), green ash
(Fraxinus pennsylvanica), American elm (Ulmus americana), pin oak (Quercus
palustris), sycamore (Platanus occidentalis), and river birch (Betula
nigra). The shrub layer is dominated by spicebush (Lindera benzoin), highbush
blueberry (Vaccinium corymbosum), and winterberry (Ilex verticellata).
Common herbaceous plants include, royal fern (Osmunda regalis), sensitive
fern (Onoclea sensibilis), garlic mustard (Alliaria petiolata), arrow-leaved
tearthumb (Polygonum sagittatum), white snakeroot (Eupatorium rugosum),
spotted jewelweed (Impatiens capensis), cardinal-flower (Lobelia cardinalis),
and skunk-cabbage (Symplocarpus foetidus).
Most of the refuge's wooded
wetlands are red maple swamps along the Wallkill River. A small but significant
type that also occurs on the Refuge is Atlantic white-cedar swamp. Wetland
forests dominated by Atlantic white-cedar (Chamaecyparis thyoides) were
once widespread along the eastern seaboard. However, the range of this
habitat type has contracted significantly from harvest without re-planting,
hydrologic alteration, and coastal development. In fact, The Nature Conservancy
considers the Atlantic white-cedar swamp a globally endangered ecosystem.
Important plant associates on the Refuge include black spruce (Picea mariana),
highbush blueberry, and sphagnum (Sphagnum spp.).
Approximately 1,400 acres of
emergent marsh is found on the refuge. Dominant species include cattails
(Typha spp.), spikerushes ( Eleocharis spp.), sedges (Carex and Cyperus
spp.), smartweeds (Polygonum spp.), arrow-arum (Peltandra virginica),
pondweeds (Potamogeton spp.), swamp loosestrife (Decodon verticillatus),
and common reed (Phragmites australis). Purple loosestrife (Lythrum salicaria)
is dominant in many marshes. An additional 100 acres of the Refuge is
open water. Species found here include pondweeds, spatterdocks (Nuphar
spp.), and duckweeds (Lemna spp.).
Approximately 600 acres of
the Wallkill River Refuge's wetlands are comprised of wet meadow. The
dominant plant species in these areas is reed canary grass (Phalaris arundinacea).
Other common plants are swamp milkweed (Asclepias incarnata), joe-pye-weeds
(Eupatorium spp.), common reed, purple loosestrife, and cattail.
Approximately 400 acres of
the Wallkill River Refuge are classified as scrub-shrub wetland. These
areas are currently in a successional stage leading to forested wetland.
The dominant shrub species include silky dogwood (Cornus amomum), multiflora
rose (Rosa multiflora), and spicebush Representative trees include red
maple, black willow (Salix nigra), and American elm. Sensitive fern, tussock
sedge (Carex stricta), purple loosestrife, and skunk-cabbage are common
herbaceous plants.
Calcareous fens are an uncommon
but important wetland habitat on the Wallkill River Refuge. This wetland
type develops in areas of calcareous groundwater discharge. The high availability
of calcium in these rich fens yields a unique assemblage of plants, including
tufted hairgrass (Deschampsia cespitosa), swamp birch (Betula pumila),
shrubby cinquefoil (Potentilla fruticosa), willows (Salix serissima, S.
discolor, S. gracilis), and poison sumac (Toxicodendron vernix). Also,
the continuous groundwater seepage and open vegetation are important habitat
characteristics that make these sites suitable for the Federally threatened
bog turtle (Clemmys muhlenbergii). Dominant plants in Refuge fens are
tussock sedge, red maple, American elm, multiflora rose, and purple loosestrife.
<top of page>
|
Wallkill River
The Wallkill River is one of the
few large rivers in the United States that flows north. From its headwaters
in spring-fed Lake Mohawk, located in Sparta, New Jersey, the river flows
north into New York State. It joins the Rondout Creek in Rosendale, New York
and empties into the Hudson River in Kingston, New York. The Refuge is part
of the Hudson River-New York Bight watershed.
The Wallkill River National Wildlife
Refuge is currently participating in watershed planning of the Wallkill River.
Please see http://www.wallkillriver.org for more information.
<top of page>
|
Invasive
Species
Non-indigenous, invasive species
are a serious threat to wildlife and habitats at Wallkill River Refuge. Exotic
plants degrade habitat by converting diverse native plant communities into
single-species monocultures. Introduced animals compete directly with native
wildlife. In fact, invasive speries are one of the most important threats
to the the National Wildlife Refuge System as a whole.
All refuge habitats and wildlife
species are vulnerable to the effects of invasive species. Purple loosestrife
and Phragmites have taken over many Refuge wetlands. Consequently, habitat
for the Federally threatened bog turtle, migrating waterfowl, and a wide diversity
of other wetland dependant wildlife has been degraded. Refuge grasslands are
being invaded by Canada thistle. Shrublands are becoming dominated by multiflora
rose, common buckthorn (Rhamnus cathartica), and autumn olive (Elaeagnus umbellata).
Refuge forests have become invaded by tree-of-heaven (Ailanthus altissima),
Japanese barberry, and garlic mustard. The introduced mute swan (Cygnus olor)
competes with native waterfowl and marshbirds for food resources and nesting
areas. Further, the feeding activities of these large birds damages wetland
ecosystems. Feeding and spawning common carp (Cyprinus carpio) kill aquatic
plants and increase water turbidity. As a result, Refuge waters provide poorer
habitat for native fish. Feral cats kill countless small mammals, ground-nesting
birds, and songbirds. Other important invasive species on the Refuge include
Japanese honeysuckle (Lonicera japonica), European bush-honeysuckles (L. tatarica,
L. morrowii), Asiatic bittersweet (Celastrus obiculatus), Norway maple (Acer
platanoides), Japanese knotweed (Polygonum cuspidatum), and gypsy moth (Porthetria
dispar).
The refuge is currently participating
in a Regional Invasive Plant Species inventory and Mapping Initiative. The
purpose is to conduct a basic invasive plant inventory of refuge lands which
will locate, identify, and map invasive plant species. This information will
be used to guide development of control, monitoring, and evaluation initiatives.
<top of page>
|
|
