Conservation Work at Arcadia
Arcadia Wildlife Sanctuary is approximately 720 acres of wetland, grassland, and forest, adjacent to the Oxbow of the Connecticut River. Arcadia serves several key conservation functions.
- It provides habitat for dozens of rare species and species of special interest including freshwater mussels, dragonflies and damselflies, and grassland- and shrubland-nesting birds.
- It is a significant stepping stone in a wildlife corridor of regional importance. Black bear and bobcat, among other wide-ranging species, are found on the sanctuary.
- It serves as a stopover site on a major East Coast migratory bird flyway for waterfowl, raptors, and songbirds. Briefly in the spring, the wetlands, and the adjacent Oxbow, host thousands of Canada geese and many species of ducks.
Arcadia has a diversity of habitats, some naturally occurring while others rely on active management to maintain.
Indigo bunting © Phil Doyle
Shrubland
Shrubland is early-successional forest, meaning it consists of small diameter trees and shrubs. More than 32 acres in Arcadia’s meadows are currently managed as shrubland, and are in various stages of development. Sections of shrubland have been cut at different times, resulting in a mosaic of woody early-successional growth phases, from areas that have more than 20 years of growth to areas with less than five years of growth. These shrublands form a transitional area between the agricultural fields and grasslands, and the floodplain forest.
Shrubland Species
Trees that can be found in Arcadia’s shrubland include: Black locust, gray birch, quaking aspen, cottonwood, American elm, white pine, honeysuckles, speckled alder, silky dogwood, and staghorn sumac.
Bird species that rely on shrublands include brown thrasher, chestnut-sided warbler, and indigo bunting.
Shrubland Management
Management of shrubland requires occasional cutting of larger trees to prevent the shrubland from turning into a mature forest. While cutting down larger trees can appear to have a negative impact on the ecosystem, it is needed to maintain this important and declining habitat.
Visitors to Arcadia may see evidence of shrubland management including tree stumps in the orchard area and edge of the meadows.
Meadows
The Arcadia Meadows are divided into two sections: the Manhan Meadows north of Ned’s Ditch and the Rookery, and Pynchon Meadows south of Ned’s Ditch and the Rookery.
A major focus of Arcadia’s ecological management program has been the establishment and maintenance of open cover types, together covering nearly 200 acres. These areas consist of native and non-native grasslands, forb-dominated weedlands, and agricultural lands.
Mountain View Farm leases 61 acres for agricultural use. Crops grown in the leased fields have included hay, corn, potatoes, various squashes, cucumbers, various mustard-family vegetables, and others. In some cases, row crop cultivation (due to the timing of cultivation, the crop produced, cover planting, or other factors) has provided cover and breeding or stopover habitat for some species of migratory songbirds.
Grass and Plant Species
Grass species in the non-cultivated area of the meadows include big bluestem, Canada wild rye, timothy, switchgrass, Indian grass, orchard grass, Kentucky bluegrass, smooth brome, quack grass, yellow foxtail, and deer-tongue, among others.
Portions of the meadows, known as weedlands, include more forb species (herbaceous flowering plants that are not grasses, sedges or rushes). Common forbs include giant ragweed, common evening primrose, common milkweed, Canada thistle, Queen Anne's lace, bedstraw, sensitive fern, fleabanes, and a variety of goldenrods, including tall, early, and rough goldenrod.
Birds and Meadows
This open land provides important habitat to many bird species such as eastern bluebird, bobolink, American kestrel and many others. Birds relying on grassland habitat, which makes up most of the Arcadia Meadows, have declined more in the past 30 years than birds relying on any other habitat type.
Priority Natural Communities
The Massachusetts Natural Heritage & Endangered Species Program (NHESP) defines Priority Natural Communities as "natural communities that have limited statewide or global distribution."
NHESP's Natural Communities Datalayer (2006) includes two Priority Natural Communities associated with the Mill River at Arcadia Wildlife Sanctuary:
- a small river floodplain forest
- a high terrace floodplain forest
NHESP ranks both of these communities as S2 imperiled, indicating they are very vulnerable to extirpation from the state. S2 designees have 6 to 20 occurrences, very restricted range, and few remaining acres or miles of stream.
Additionally, we have surveyed and mapped another imperiled community—Black Gum-Pin Oak-Swamp White Oak Perched Wetland.
Vernal Pools
A total of 31 vernal pools occur on the sanctuary. Amphibian egg mass tallies have been conducted annually for more than a decade. These pools support varying populations of Wood Frogs as the main vernal-pool breeding amphibian; low numbers of Spotted Salamanders also use some pools. There are 21 pools that are formed by Connecticut and Mill River flooding that support Fairy Shrimp.
Black Gum-Pin Oak-Swamp White Oak Perched Swamp
Arcadia staff has also surveyed and mapped three forested wetland tracts that fit this S2 Natural Community description. In Massachusetts, this community type is limited to the Connecticut River Valley where low-lying areas create a perched water table over the impervious clay sediments of Glacial Lake Hitchcock.
Red Maple is usually the dominant tree species, but Black Gum (Tupelo), Pin Oak, and Swamp White Oak are important components of the canopy. Hemlock, American Beech, and Yellow Birch may also occur. Shrubs include Winterberry, Highbush Blueberry, arrowwood, Serviceberry, and sometimes Mountain Laurel. Cinnamon Fern characteristically grows on the higher parts of the hummock and hollow terrain. Sedges may grow in the hollows.
The three sites—Red Maple Swamp, Tupelo Swamp, and Hitchcock Swamp—differ somewhat in the dominance of the canopy species, but all are well delineated by Cinnamon Fern, and the clay layer is between 5-24 inches below the surface. Pin Oak and Swamp White Oak are absent from Red Maple Swamp, while large specimens occur in Hitchcock Swamp.
Tupelo Swamp transitions from mainly hardwoods (red maple, black gum, pin oak, swamp white oak, white oak) to a mixed canopy (hemlock, red maple, black gum, swamp white oak, white oak, and American beech). Virtually the entire western forest is perched on Lake Hitchcock clays, with some areas better drained than others. Hummock and hollow topography is common. Drainage ditching is evident around Tupelo Swamp.
Small River Floodplain Forest
"Small-River Floodplain Forests are silver maple/green ash forests occurring on alluvial soils of small rivers and streams. They occur on small tributaries of the Connecticut and Nashua Rivers and along some small rivers of eastern Massachusetts. Alteration of the natural hydrologic regime that created floodplain forests and their natural closed-canopy forest structure threatens these communities, particularly by allowing the establishment of invasive species.
"This moderate-sized example [covering approximately 26 acres] of Small-River Floodplain Forest is one of the three best examples of this type in the state. It has good structure and diversity, and is well buffered by natural vegetation." — NHESP
High Terrace Floodplain Forest
"High-Terrace Floodplain Forests are deciduous hardwood forests that occur along riverbanks, above the zone of annual flooding. Although they do not flood annually, they flood often enough for the soil to be moderately enriched. Changes in natural flooding patterns that create floodplain forests threaten these communities. Most high terraces have been converted to agriculture or developed, leaving small, fragmented, and disturbed examples. This example of High-Terrace Floodplain Forest is quite small [less than 2 acres] and in somewhat degraded condition." — NHESP
Field work by Arcadia staff indicates that the High Terrace Floodplain Forest is of greater extent and quality than NHESP recognizes. This survey and mapping includes over 12 acres of High Terrace Floodplain Forest, ranging from a narrow band near the mouth of the Mill River, to approximately 200 feet wide along parts of the Fern Trail and River Trail, and tapering north toward the old dump site.
This community is not degraded except for a concentration of oriental bittersweet in the ground layer near part of the Fern Trail. These vines are cut periodically when they begin to climb the trees.
Transitional Floodplain Forest
Additionally, NHESP maps a third area of floodplain forest—a Transitional Floodplain Forest—along the inside bank of the Oxbow, opposite from Arcadia. NHESP notes that this area is moderate in size [approximately 21 acres] but is in good condition, and is one of only five areas of its type known to occur in the state.
Transitional Floodplain Forests are "Riverside Silver Maple-Green Ash-American Elm forests that experience annual floods. Of the three floodplain forest community types, these communities are intermediate in vegetation and soils." As with other floodplain forests, alteration of the natural hydrologic regime can threaten the distribution and long term viability of these woodlands.
Restoring Floodplain Forests
Arcadia Wildlife Sanctuary is restoring 8.5 acres of field that is unproductive for both farming and grassland bird habitat into a floodplain forest dominated by trees—including pin oaks, silver maples, and even American elm. Learn more >