Assabet River NWR Final CCP - U.S. Fish and Wildlife Service

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Chapter 3: Refuge and Resource Descriptions
Biological Resources
Vegetation and Habitat Types
Service biologists completed a survey and evaluation of the habitat of
portions of what then was still the Fort Devens Sudbury Training Annex in
1992 (USFWS 1995). Short duration site visits, wetland mapping produced
by the Service’s national wetland inventory team, forest cover mapping
completed by the Fort Devens Natural Resource
Management Office (NRMO), aerial photographs and
other existing data were used in the evaluation. The
focus of this evaluation was the eastern portion of the
property north of Hudson Road.
The report notes that aerial photos, extensive stone
walls, successional second-growth forests, old cranberry
bogs and discussions with knowledgeable people all
document the fairly extensive farming history of the
land prior to the Army’s acquisition in the early 1940’s.
The presence of diverse wetland and upland habitat of
high value to wildlife species was noted. Others have
suggested that the diversity of habitat found on the
refuge is due to the presence of highly varied
topography, soils, drainage patterns, and the Army’s
ownership and management of the property over a 50
year time span.
Although only portions of what is now the refuge were
evaluated, the report found 476 acres of wetland habitat.
North of Hudson Road, approximately 291 acres (67%)
were forested or mixed forested/shrub cover; 29 acres
(7%) were shrub dominated; 41 acres (9%) were
shrub/emergent herbaceous cover; 62 acres (14%) were
open water ponds; and 14 acres (3%) were former
cranberry bogs. The report indicated the portion of the
Grasses: Photo by Emily Ann Hollick
property south of Hudson Road contained
approximately 39 acres of wetlands (~9% of the area).
Approximately 87% of these wetlands were forested and the remainder was
shrub-dominated wetland habitat.
The forested wetlands are dominated by red maple (Acer rubrum) with
black ash (Fraxinus niger), swamp white oak (Quercus bicolor), and some
eastern hemlock (Tsuga canadensis) and white pine present. Understory
shrubs included sweet pepperbush (Clethra alnifolia), swamp azalea
(Rhododendron viscosum), european buckthorn (Rhamnus frangula),
winterberry (Ilex verticillata), and maleberry (Lyonia ligustrina). At least
one remnant Atlantic white cedar (Chamaecyparis thyoides) wetland was
Assabet River NWR