Table 2: SuAsCo Biodiversity Sites
M#	Site name	Town(s)	Asso. streams	River	Acres	Natural communities	Values	Biodiversity Concerns
1	Mt. Pisgah	Northboro Berlin	North Brook, Cooledge Brook, Howard Brook	Assabet	450 1300 =36%	Shrewsbury Ridge with extensive oak and oak/hickory forest mosaic on shallow soils; steep ravine with hemlock; acidic rock outcrop; vernal pools; forested seeps; red maple swamp	Largest tract of unprotected, unroaded land in watershed with low density development around it (still much Ch. 61 land), represents typical Shrewsbury Ridge habitats; interior forest focal species; bear sign; black rat snakes and waterthrushes.	Forest has been cut over frequently; surrounding Ch. 61 property being cut; shallow soils are subject to erosion.
2	East Woods, Wrack Meadow, Rocky Pond	Boylston	Cold Harbor Brook to S, French Brook to W, and North Brook to N.	Assabet (Nashua)	210 835 =25% 65 735 =9% 270 745 =36%	Mixed oak forest on glacial till; vernal pools, possibly several in Wrack Meadow; pond & peatlands in Rocky Pond; young successional red maple swamp and peatlands in Wrack Meadow	On watershed divide and connected to Mt. Pisgah; large unfragmented tracts of forest; headwaters of three streams; vernal pool cluster; seeps; and pond; most varied combination of communities along the ridge; NHESP; Rocky Pond is headwaters of Cold Harbor Brook	Three areas divided by road; increased fragmentation by development; some development around Rocky Pond; golf course in SW corner; imminent development in Wrack Meadows.
3	Rattlesnake Hill	Berlin Boylston	North Brook	Assabet (Nashua)	75 495 =15%	Dry oak forest on shallow bedrock soils and glacial till; south facing, extremely ledgy slope along tributary to North Brook.	South facing, ledgy slope habitat for amphibians and reptiles; stream wraps around three sides of hill with narrow impoundment to northeast.	Reubens Hill to north has proposed 400 unit condo development that will likely affect water quality of stream.
3	Reubens Hill & Clamshell Pond	Clinton Berlin	North Brook	Assabet (Nashua)	90 425 =21%	Oak forest on shallow bedrock; natural pond.	One of the few, if not the last, undeveloped natural ponds in SuAsCo; currently well buffered; supports fresh water mussels; closet point to Wachusett Reservoir and protected MDC buffer lands in Nashua River watershed; NHESP for particularly unusual species in watershed.	Imminent development by 400 condo units will likely impact water quality not only of Clamshell Pond but tributary to North Brook.
4	Wataquadock Fields	Bolton	Mill Brook	Assabet	25 475 =5%	Cultural grasslands - hay and pastures; ponds and first-order streams.	Mosaic of grasslands for bobolinks, meadow larks and kestrels; protection of first- and second- order streams feeding into Mill Brook; NHESP; proximity to watershed divide.	Mowing regimes could create a “sink” of nesting birds; runoff from agricultural uses could impact use of stream systems and ponds by herps.
4	Sunk Meadow & Hog Swamp	Bolton Berlin	Mill Brook to Danforth and Hog Brook	Assabet	50 1000 =5%	First- and second-order streams; mosaic of cultivated wet meadows; shrub swamp and red maple swamp.	Sub-basin divide; Sunk meadow protects extensive network of streams draining into Mill Brook; current farm use creates wet meadows; NHESP.	New development is increasing use of roads network and fragmenting habitat; wet meadows that are a result of current agricultural use may not continue to be open.
5	Powder House Hill & Golden Run “Hill”	Bolton Harvard	Tribu-taries to Great Brook to Elizabeth Brook	Assabet	5 480 =1%	Oak forest matrix with first-order streams with associated focal species; vernal pools.	One of few remaining tracts with seeps and intermittent streams in the region; herps; protection of native trout stream.	Development is beginning to fragment these sites.
5	Rattlesnake Hill	Bolton	Great Brook	Assabet	270 665 =40%	Limy plant community, vernal pool complex and cool seeps; Trout habitat; unusual herp habitat.	Historical lime kiln provides habitat for sweet-soil loving plants; vernal pool complex (16 VPs) and seeps; Protections portion of Great Book which connects with Delaney Pond and Elizabeth. Brook. Trout waters, NHESP.	Calcareous habitat result of human excavation and does not form a intact community type; hemmed in by I-290 and Rte 117. Stream connection threatened. Needs safe linkage to vernal pools north of Sugar Road.
6	Cold Harbor Brook Impoundment	Northboro	Cold Harbor Brook	Assabet	250 460 =55%	Alder/willow shrub swamp and blue joint grass, cattail marsh with stream.	Unusual shrub swamp for SuAsCo due to species composition and minimal exotics; high quality water; NHESP; trout stocking	Water control dam and town water supply affects water flows; Crawford St. on W boundary becoming busier; Rte 20 very busy; development on E around perimeter threatens hydrology.
7	Crane Swamp to Westboro WMA	Westboro Northboro Marlboro Southboro	Stirrup Brook	Assabet Sudbury	1760 2600 = 67%	Mature red maple swamp > 500-700 acres, cultural wet meadows, successional shrub habitat >250 acres, lake and 2 ponds, AWC stand; upland fields; seepage swamp and mature yellow birch forest.	Combination of several important communities: very large red maple swamp in MDC protected watershed, successional shrub habitat managed by DFW; three connected water bodies; extensive agricultural fields for grassland birds and overwintering birds; connection between the two watersheds; wetland and upland corridors to other protected areas; intact drumlin; NHESP.	Increased industrial development around the north side; fragmentation due to development of state hospital land and consequent loss of linkage across Lyman St.; increased traffic on road; invasive exotics due to fragmentation and edge effect around fields, MDC forest, and ponds; potential colonization of exotics into red maple swamp from new water treatment plant.
8	Cedar Swamp	Westboro Hopkinton	Jackson & Denny Brooks, Piccadilly Brook, Whitehall Brook, Rutters Brook	Sudbury	800 2100 =38%	AWC swamp within red maple swamp,	ACEC, AWC swamp with many focal species; NHESP.	Swamp divided and confined by ConRail, interstate highways, and industrial development which compromises hydrology.
9	Whitehall Fens and Reservoir	Hopkinton (Upton)		Sudbury	2000 2700 93%	100 acre acidic fen and AWC swamp.	Excellent community example well buffered to S; no exotics; NHESP; potential use of reservoir by migrant waterfowl	Recent housing development and road to N drains into fen area which could alter hydrology; AWC stand will need disturbance to replace itself; reservoir gets significant recreational use.
10	Delaney Wetlands	Harvard Stow	Elizabeth Brook	Assabet	610 980 =62%	Fen with black spruce N of Eldridge Rd, marsh, open water with aquatic beds with surround- ing white pine forest on glacial outwash; shrub swamp.	Large marsh with variety of marshland bird and herp focal species; migrating waterfowl; connection to Nashua River and Stony Brook River watersheds through Wolf Swamp connector; adjacent to Rattlesnake Hill and Great Brook (see above).	Artificial impoundment; intensive public use for fishing, hunting, and dog walking; fragmentation of marsh to south (Hiley Meadows) by roads.
11	Heath Hen Meadow	Stow Acton	Heath Hen Meadow Brook, Flagg Hill Brook	Assabet	600 3000 =19%	First- to third- order stream; red maple swamp; white pine/oak forest; vernal pools	One of largest red maple swamp and stream systems in the watershed with only two road crossings and over 3 miles of relatively unfragmented stream with low density residential development around perimeter; provides extensive wildlife corridor. (see also “Great Swamp”)	Two main roads run over brook; airport with associated wetland vegetation management; increased development and traffic.
12	Great Swamp	Acton Stow Maynard	Heath Hen Meadow Brook, Muddy Brook, Fort Pond Brook	Assabet	see above	Red maple swamp	One of largest red maple swamps in the watershed; connected to Heath Hen Meadow Brook; lies in the heart of the watershed and serves as linkage between east and west; limited development along much of its perimeter.	Three long roads extend through swamp (South Acton and W. Acton Roads, Red Acre Road); road repairs could create sources of exotics, alter hydrology, and sever connection.
13	Rte 2 Rookery	Littleton	Fort Pond Brook	Assabet	22 140 =15%	Extensive beaver impoundment with heron rookery; 6 vernal pools.	Currently the most active heron rookery in watershed; also nesting hooded mergansers and cormorants; extensive wetland bounded by highway and railroad so little human access; beaver will likely continue to disturb this area over time; owned in large part by Div. of Fisheries and Wildlife so can be managed for biodiversity; few invasive exotics; feeds headwaters of Fort Pond Brook tributary.	Small size, bounded by both an active RR and major highway; large pines will eventually break apart so that the herons will move on; not clear as to wildlife values after loss of herons; tenuous linkage to east along Fort Pond Brook.
14	Long Pond/ Fort Pond	Littleton Acton	Fort Pond Brook	Assabet	70 375 =19% 100 560 =18%	Two great ponds; springs; vernal pools; white pine; mixed oak/white pine forest on both former pasture and cultivated sites; fields, and successional fields, and orchard; hard pan glacial till.	Two large unimpounded lakes buffered and connected by more or less protected land; headwaters of Fort Pond Brook; mixture of fields, orchards, successional forest and mixed forest types provide habitat for many common edge species and far roaming species; adjacent to other protected areas of Grassy Pond and Nagog Pond so together provide relatively large protected area in this part of watershed with variety of open water bodies. NHESP herps.	Two ponds separated by busy intersection of Newtown and Nashoba Roads and Harwood Avenue; dense development around 1/3 of Long Pond compromises habitat values; scattered low density development could become dense development in later years; exotic species.
15	Grassy Pond	Acton	Grassy Pond Brook	Assabet	90 190 =48%	Graminoid acidic fen; black birch forest, and red maple swamp.	One of very few graminoid fens in the eastern part of watershed; forest of black birch and hop hornbeam unusual; red maple swamp appears to be of good diversity and sparse loosestrife; now with active beaver; NHESP.	Limited buffer for area that depends on hydrological integrity for long term; relatively small tract for turtles and other herps.
15	Will’s Hole	Acton	Nagog Brook to Fort Pond Brook	Assabet	40 90 =43%	Acidic Level Bog	One of few bogs in watershed.	Not sure if the hydrology has changed as a result of industrial park in its watershed. beaver also affecting water height.
15	Nagog Pond and Brook	Littleton Acton	Nagog Brook	Assabet	350 1030 =35%	Great pond and surrounding mixed oak forest; seeps, vernal pools; soils range from rocky, well drained to hard-pan glacial till.	Extensive protected pond edge; headwaters of brook, and protection of over 5000’ of Nagog Brook; significant stop- over for migratory ducks and waterfowl; common loon, bald eagle, osprey have been recorded; protected water quality; stocked trout	Water supply for Concord subjects pond to unnatural controls; Nashoba Road and Rte 2A run eastern riparian zone.
16	Spring Hill/Nashoba Brook	Acton Carlisle	Nashoba Brook	Assabet	315 1100 =28%	Mixed oak forest with wetland seeps; hemlock grove; red maple swamp; third- order stream; perched water-table on compact glacial till.	One of last remaining large forest tracts in eastern part of watershed; protects over a mile of Nashoba Brook; oak forest with seeps; stocked trout; important wildlife corridor; beaver and fisher focal species	Imminent development, traffic on surrounding roads diminishes interior area; roads and development along west side of brook; river corridor is greatly compromised at intersection of Rte 27 and 2A.
17	Assabet Marshes	Stow Hudson	Fort Meadow Brook	Assabet	100 900 =11%	Emergent marsh, shrub swamp, and flood plain forest mosaic; red maple swamp; beaver meadow.	Most convoluted stretch of Assabet River with extensive marsh in bays and along river; excellent example of marsh along Assabet; excellent sites for migrating waterfowl; bank swallows, otter, marsh and swamp sparrows,	Development to south; sewage treatment plant; poor quality water of Assabet fosters intense aquatic invasive growth in river.
18	Gardner Hill and Crow Island	Stow	Elizabeth Brook	Assabet	390 850 =11%	Emergent marsh, white pine stands, kettle hole bogs.	Connection between Assabet and Elizabeth Brook; one of few selected areas with mature white pine stands; good example of kettlehole bog; extensive emergent marsh along Elizabeth Brook; NHESP.	Intensive public use; invasive purple loosestrife in marsh; Crow island has been severely altered; active recreational use is inconsistent with surrounding natural areas.
19	Assabet NWR & environs Assabet NWR & environs (cont.)	Stow, Maynard Sudbury Hudson	Taylor Brook	Assabet	1440 2600 = 55%	Kettle hole and level bogs, fens, red maple swamp, emergent marsh, free flowing brook, undeveloped pond; 50-60 year forest mosaic; grassland.	Large size, mosaic of different habitats both wetland and upland on glacial outwash; AWC stand; ownership mandate to preserve biodiversity; NHESP for both plants and animals; many focal species including grassland and interior forest birds, whip-poor-wills.	Past land use as military base has compromised soil integrity; illegal recreational use of ORVs compromise habitat values for plants and animals; potential of intensive public use.
20	Desert Area	Sudbury Marlboro Hudson Stow	Trout & Cran-berry Brooks flow into Hop Brook	Sudbury	860 1900 =44%	Pitch pine/scrub oak, red maple swamp and emergent marsh, beaver meadow, trout stream; glacial outwash soils.	Mosaic of glacial outwash habitats; drumlin and eskers; only significant area of pitch pine/scrub oak in watershed; tract connected to large areas to north and providing corridor south; focal species including whip-poor-will, goshawks; low density of upland exotics; NHESP.	Gas pipeline corridor slices through center; ORV use continues to be a problem; abandoned RR line may become source of fragmentation if become bicycle trail; fire dynamic needs to continue to sustain pitch pine habitat; purple loosestrife and phragmites coming into beaver meadow.
21	Nobscot Hill	Sudbury		Sudbury	260 1200 =22%	Acidic rock outcrop, oak forest matrix, vernal pool complex, 2-3 rocky cool water brooks, hemlock groves on compacted till.	Large forest mosaic with cool water streams unusual in eastern in watershed; high quality rock outcrop and vernal pool complex; eastern most record for dusky salamander; part of central watershed corridor; NHESP; important herp and wildlife sightings.	imminent development on Nobscot Hill threatens integrity of area;
22	Baiting Brook Baiting Brook (cont.)		Baiting Brook, Angelica Brook		970 1500 63%	Baiting Brook with yellow birch/hemlock swamp; little bluestem fields and cultivated grasslands.	Grassland birds of meadowlark and bobolink; connection west to Sudbury reservoirs system through Pine Hill.	Intense public use of Fragmentation due to roads, pipeline and heavily developed residential areas; variety of habitats so less interior forest and a lot of edge with consequence of exotic species; number of different ownerships so management difficult; state park compromises wildlife values
23 &29	Great Meadows	Framing-ham, Wayland Sudbury Concord Carlisle, Bedford, Billerica		Assabet Sudbury Concord	3700 5000 = 74%	Deep and shallow emergent marshes, wet meadows, shrub swamps, small river floodplain forest, alluvial red maple swamp	Core is a National Wildlife Refuge and Wild and Scenic River; more or less natural flow and flooding dynamic; extensive marshes and floodplain forest, and other associated wetland communities - some unique to SuAsCo; many NHESP records for herps, birds, and plants; migratory waterfowl and passerine birds; many focal species; ownership mandate to preserve biodiversity.	Exotic species including loosestrife throughout, phragmites in smaller colonies; aquatic invasives such as water chestnut and carp; increasingly intensive public use on water and land; water quality issues connected with upstream quality and water controls.
23	Heard Farm	Wayland		Sudbury	75 75 =100%	Cultural grassland (hayfield) next to Sudbury River	One of few large, productive bobolink fields in watershed which is under conservation commission management.	Inappropriate public use and mowing regimes could affect nesting birds.
23	Pine Brook Pine Brook (cont.)	Wayland	Pine Brook	Sudbury	65 135 13%	Cattail/loose-strife shrub swamp along stream adjacent to mature oak pine forest	Extensive marsh with sightings of bitterns; unusually cool water; extends upstream via Hayward Brook to connect to Charles River Watershed in Weston; only stream chosen which drains into Sudbury/Concord River from east.	Lower portion is golf course; upstream fragmented by residential housing.
24	Allowance Brook Wetlands	Framing-ham Sudbury	Allow-ance to Wash Brook	Sudbury	310 550 =57	Cattail marsh and willow/ dogwood shrub swamp with adjacent red maple alluvial swamp	Directly adjacent to Sudbury River, upper reaches of relatively high quality water and well buffered due to water supply; NHESP; bittern and wood turtle records; shorebirds especially snipe migrate.	Extensive purple Loosestrife and phragmites colonizing; 2-3 road crossings, including one commuter route; town water supply so withdrawals; also edge of old town dump and other toxic land uses.
24	Pod Meadow/ Oxbow	Framing-ham Wayland		Sudbury	150 325 =45%	Deep emergent cattail marsh, beech forest	Almost pure beech forest on south facing ice contact slope; old oxbow of river; connection to river; extensive cattail marsh with little purple loosestrife; potential for marsh birds; otter observed.	Next to MWRA aqueduct and utility corridor; MWRA uses as emergency overflow area; oxbow area has been graveled; exotic upland species prevalent on nearby land although beech forest and cattail marsh are remarkably clear of invasives.
24	Strand	Sudbury		Sudbury	115 130 =88%	Pond, marsh, beaver meadow, floodplain forest	Well protected mixed wetland habitat very attractive to migratory waterfowl adjacent to Great Meadows; owned by USFWS.	Keep closed off; limit DPW activity at culverts.
25	Pantry Brook Bottomland	Sudbury	Pantry and Cold Brooks	Sudbury	510 800 =64%	Vernal pool complex, emergent marsh, and shrub swamp mosaic with pine oak upland	Glacial Lake Sudbury; largest population for bluespotted salamanders in eastern Mass.; numerous other herps such as 2-lined and 4-toed salamanders, red bellied and ring-necked snakes. Extensive duck habitat; nesting winter wren; spring warblers along Pantry Brook	Exotic purple loosestrife is dominant throughout much of the marsh; water quality of Pantry Brook compromised by upstream development; fragmentation by roads hazardous to herps.
27	Second Division Brook	Concord	Second Division Brook	Assabet