Preliminary Biodiversity Assessment,
Proposed Hillcrest Commons Subdivision Site,
Towns of Carmel and Kent,
Putnam County, New York ork
Erik Kiviat, PhD
Tanessa Hartwig, MS
P.O. Box 5000, Annandale NY 12504
Report to James Bacon, Esq. and Croton Watershed Clean Water Coalition
29 July 2005
Biodiversity, or the variety of life in nature, is critically important to
human society. Many of the native species of plants, animals, and other
organisms which constitute biodiversity in the Hudson Valley are under threat
of habitat loss and degradation, road mortality, collecting, the invasion of
introduced plants and animals following disturbance to soil and vegetation, and
other impacts of land development. Assessing the biodiversity of a proposed development
site and its surroundings is necessary to allow reduction of these and other
At the request of James Bacon, Esq., and the Croton Watershed Clean Water
Coalition, Hudsonia conducted a preliminary biodiversity assessment of the
proposed Hillcrest Commons development site in the towns of Carmel and Kent, Putnam County, New York. The site is on the east side of Route 52, with the northwestern
corner of the site across Route 52 from Dykemans Road and near the Kent-Carmel
town line. On 12 July 2005, Kiviat visited the site (5 hours), and on 24 July
2005, Hartwig and a field assistant visited the site (8 hours). Both days were
hot and humid with minimal wind or precipitation during the field work.We
reviewed portions of the Draft Environmental Impact Statement (DEIS) and
studied topographic and soils maps and aerial photographs. We used our field
observations, our knowledge of biodiversity and habitats in the region (Kiviat
and Stevens 2001 and unpublished data), and other information to assess the
likelihood that animal species listed in New York State as Endangered,
Threatened, or Special Concern, plants listed by the New York Natural Heritage
Program as S1, S2, or S3, or biota considered regionally-rare would be present
on or near the Hillcrest Commons site. We paid special attention to shining
bedstraw (Galium concinnum), an endangered plant reported ambiguously in
the DEIS. This report summarizes our observations and preliminary assessment,
and offers comments on some potential impacts of the proposed development on
the biodiversity of the site.
Hudsonia Ltd. is a non-advocacy scientific research institute, and does not
support or oppose development projects. Rather we make scientific observations
and collect data from the field, literature, and other sources, identify
sensitive habitats and species, and make recommendations concerning reduction
of development impacts.
Results and Discussion
We are aware of two wetlands: Wetland A on the northwestern corner of the
site, and Wetland B in the southwestern areas of the site. A large portion of
Wetland A lies between the north end of the shopping plaza parking area and the
proposed entrance road location at the northwestern corner of the site; maps in
the DEIS show that portions of this wetland are offsite. However, the offsite
portions of the wetland are currently subject to impacts from the shopping
plaza and will be subject to impacts from the proposed Hillcrest Commons
entrance road, thus need to be considered in the SEQRA review.
Nmbered flags indicate that wetlands A and B were delineated by the applicant.
Portions of Wetland B may have been omitted from the delineation. If not
already done, the applicant's wetland delineations should be checked by the
U.S. Army Corps of Engineers, corrected as necessary, then surveyed onto a
map. This will allow the Planning Board and the public to understand the extent
and locations of the wetlands and the impacts of the proposed development
Crest and Ledge Habitat
There is an extensive area of high quality crest and ledge habitat with
open-canopy hardwood forest on the west-facing slope above (east of) the
Shoprite and west of the water tower. Chestnut oak, yellow birch, gray birch,
black cherry, red cedar, blueberries, hay-scented fern, and other plants
characterise this area. Extensive rock ledges occur in the upper portions of
this area, including a ledge that is about 150 meters long from north to south
and ca. 2.5 meters high on the west (downhill) side. The ledges and intervening
woodlands contain the largest stand of spotted wintergreen (Chimaphila
maculata), a very attractive wildflower, that Kiviat has seen in 35 years
of biological field work in the Hudson Valley; many plants were in flower on 12
July. This area is a good example of non-carbonate crest and ledge habitat
which could support species of conservation concern including eastern box
turtle (Special Concern), whip-poor-will, eastern bluebird, and small-footed
bat (Special Concern). The DEIS (page 3.3-4) reported eastern box turtle on the
site but did not state where, when, or how many individuals were observed.
Additional biodiversity information for this type of habitat is in the habitat
profile for non-carbonate crest, ledge and talus in Kiviat and Stevens (2001).
We did not attempt to conduct a thorough survey for rare plants. We did
find three rare plant species on the site.
Shining bedstraw (Galium concinnum); New York Endangered
This small and inconspicuous herbaceous plant was reported ambiguously in
the DEIS (page 3.3-4). The applicant's consultants found a bedstraw at multiple
locations on the site that was believed to be shining bedstraw, but apparently
they did not consult a technical botanist for a definitive identification.
Therefore we looked for shining bedstraw and consulted the New York Natural
Heritage Program (NYNHP).
Taxonomy. Kiviat collected a specimen from the site
(northwest side of water tower) on 12 July that was subsequently examined by
botanist Steve Young (NYNHP). Young stated that the material was consistent
with Galium concinnum except the leaves were wider than typical concinnum.
Variation of this sort is common in botanical specimens. Two other species of Galium most similar to concinnum would occur in different habitat types (asprellum in wetlands and mollugo in meadows). Therefore we are considering the
Hillcrest Commons material as concinnum and of conservation concern
unless and until it is demonstrated otherwise. Additional material of this
plant was collected on 26 August and is being forwarded to Young for
Distribution on site. We found shining bedstraw at several
locations on the site (Table 1, Figure 1). The species could be present in
additional areas that we were not able to check.
Potential impacts of development. Construction of roads,
sewage systems, buildings, or other disturbances at or near the shining
bedstraw occurrences could eliminate shining bedstraw from the site. Because
this species is listed as Endangered and is known from very few localities in
the state, it deserves special consideration. According to the NYNHP web site
(accessed 29 July 2005), shining bedstraw has been confirmed during the last 20
years only in Dutchess and Putnam counties; it is listed as "Probable" (i.e., not confirmed by a specimen during the last 20
years) from four other counties, Cattaraugus, Monroe, Onondaga, and Ontario.
Therefore Putnam and Dutchess counties may be the last extant range of this
species in the state. We do not know if shining bedstraw has been documented
recently at other localities in Putnam or Dutchess.
Management of shining bedstraw. All locations on the site
should be found and marked. Areas where shining bedstraw occurs, and a suitable
buffer zone (perhaps 30 meters all around, but more if there are steep slopes
above the location), should not be developed and should be off-limits to
construction equipment. Light disturbance may be necessary to maintain a viable
population as this species does not occur in deep shade on the site and
apparently requires canopy openings and possibly minor soil disturbance to
thrive. Until there is an opportunity to conduct a thorough literature search
and consult experts, we urge a conservative approach, i.e., strong protection.
It should not be assumed that leaving the plant alone will ensure its survival
onsite. Small-scale experimentation may be necessary to determine the
appropriate management regime.
Small-flowered agrimony (Agrimonia parviflora); Natural Heritage
Program Watch List.
Small-flowered agrimony is an herbaceous plant that is commonly about 0.5-1.0 m
tall; it has small yellow flowers. The species is rare east of the Hudson River and somewhat more common to the southwest of the river. Small-flowered agrimony
east of the Hudson occurs on moist to wet soils (but not in areas prone to much
flooding) in a variety of wet meadow and wetland edge plant communities in
partial to full sunlight.
Distribution on site. A stand (possibly 100 or more stems)
occurs mingled with other vegetation around the edges of Wetland B in the
southwestern portion of the site, roughly from wetland flag B-20 southwestward
or westward along trails through wetland edges or "dry-end" wetlands
(the accuracy of the location shown on Figure 1 is uncertain). There are two
additional small occurrences (2-5 plants) elsewhere: 1. Ca. 110 meters south of
water tower along a north-south wood road; and 2. Between Wetland B and the
subdivision on the southeastern edge of the site (Table 1, Figure 1). There may
be additional occurrences of this plant, for example, at Wetland B.
Potential impacts of development. Development at or near
the small-flowered agrimony occurrences could eliminate this species from the
Management of small-flowered agrimony. Management will
require protection of the occurrences with a buffer zone, perhaps 30 meters all
around, and occasional removal of tall plants such as shrubs or trees
potentially shading the agrimony. Small-flowered agrimony needs sun, and should
also be monitored for the effects of browsing by deer.
Distribution on site. One occurrence in the northwestern
wetland (Wetland A).
Potential impacts of development. Construction of the
entrance road at or near this occurrence could easily eliminate Crawford sedge
from the site.
West Virginia White and Toothwort
West Virginia white is a rare butterfly; its larvae
(caterpillars) feed only on toothworts. We looked for the host plant in the
wetland and small stream in the northwestern corner of the site. No toothworts
(Cardamine diphylla [Dentariadiphylla] or Cardamineconcatenata
[Dentaria laciniata]) were found, hence there is currently no potential
habitat for West Virginia white butterfly at that location.
Indiana bat (Endangered) and small-footed bat (Special Concern)
The Hillcrest Commons site may be within 65 km (40 miles) of
a known Indiana bat overwintering cave (hibernaculum) in the Kingston area. Indiana bats are known to migrate 65 km or farther from hibernaculum to summering areas.
Development sites within 65 km of a hibernaculum should be assessed for
potential Indiana bat summer habitat, including male roost trees, nursery colonies,
and foraging habitat. In summer, Indiana bats roost or rear young in trees 23
cm (9 inches) or larger in diameter (sometimes as small as 13 cm [5 inches]).
There are many trees 23 cm and larger on the site; among the larger trees are a
ca. 60 cm (24 inch) white ash and two 75 cm (30 inch) red oaks (Figure 1). A
ca. 75 cm (30 inch) and a ca. 90 cm (36 inch) chestnut oak and a ca. 95 cm (38
inch) scarlet(?) oak are not shown on Figure 1; they are on the rock ledges
between the Shoprite and the water tower. The stream at the eastern edge of the
site, portions of Wetland B, existing woods roads, and forest edges are
potential foraging habitat for Indiana bat. The applicant should consult the US
Fish and Wildlife Service in Cortland, New York, concerning the methods and
expertise required for an Indiana bat assessment. The site layout and removal
of trees should be planned with consideration of Indiana bat habitat.
Small-footed bat could use ledges on the site, e.g., between the
Shoprite and the water tower, for summer roosts or nurseries. The biology of
this species is relatively poorly known, but it seems to have an affinity for
rocks. Development of the ledgy areas of the site could have an impact on this
Timber rattlesnake (Threatened)
Onsite habitats, such as the west-facing crest and ledge
complex described above, could serve as foraging areas for this species if
there were a den within about 2-3 km (about 1-2 miles) of the site. There is no
known timber rattlesnake den near the site (Al Breisch, New York State
Department of Environmental Conservation, personal communication). Knowledge
concerning the distribution of this species is constantly being revised, as
exemplified by the confirmation a decade ago of the timber rattlesnake
population on Fishkill Ridge. Therefore it is possible that rattlesnakes occur
on the site but we consider the probability low.
There has been considerable dumping off the edges of the shopping plaza parking
areas (north and south of the plaza). Cursory inspection revealed furniture,
mattresses, household garbage, shopping carts, and construction and demolition
debris adjoining the margins of the parking areas. In addition, there are some
piles of construction and demolition debris on the site perhaps 30-50 meters
off the southeastern corner of the shopping plaza parking area. This dumping
has created a hazard to wildlife and a source of pollution to Wetlands A and B.
Furthermore, refuse that collects standing water (e.g., containers) is likely
to provide breeding habitat for mosquitoes that are potential vectors of West Nile virus. The dumps should be investigated for possible hazardous substances (e.g.,
asbestos, pesticides, petroleum hydrocarbons, metals) that might contaminate
ground or surface water or generate airborne contaminants. Following this
investigation, the dumps should be cleaned up appropriately and further dumping
Portions of Wetland B close to the southeastern corner of the shopping plaza
are degraded, apparently by stormwater drainage (via at least one pipe and
possibly direct runoff) from the parking areas. The visual appearance of the
vegetation and sediments indicates water quality degradation, probably from
nutrients, organic matter (food wastes??), and petroleum hydrocarbons.
Organically-polluted surface water provides potential breeding habitat for
mosquitoes (e.g., Culex pipiens) believed to vector West Nile virus;
unpolluted wetlands are less hazardous in that regard. Stormwater from
the parking areas needs to be treated before being discharged into Wetland B.
Time did not permit us to visit every portion of the site. For example, our
coverage of the eastern end of the site was limited and we did not see the
stream corridor at the eastern site boundary. There may be additional habitats
or species of conservation concern in areas we did not cover.
Conclusions and Recommendations
The DEIS provides very little information on the biological resources of
the Hillcrest Commons site. The examples we have given above show that much
more detailed study and consideration are needed. There should be a habitat
assessment for Indiana bat and small-footed bat, conducted by a bat expert. A
thorough survey for rare plants (at least those species listed as S1, S2, or S3
by NYNHP, and regionally-rare species) on the entire site, conducted by an
experienced field botanist at the appropriate seasons, is also needed. The
three rare plant species we report above could occur at other locations on the
site, and additional rarities could also occur on the site. We also recommend a
breeding-season bird survey by an experienced field ornithologist to detect
birds of conservation concern. Rare animals and plants are disappearing from Putnam County in part because land use change is proceeding without thorough biodiversity
assessments and appropriate planning. Without surveys such as those we
recommend, it will not be possible to avoid gratuitous impacts on the
biological resources of the Hillcrest Commons site and neighboring areas. The
large trees mentioned above, and any others like them (e.g., 50 cm or larger),
should be protected. Locations of rare plants should be protected with buffer
zones. Because the west-facing crest and ledge area between the water tower and
the Shoprite is steep and contains exemplary habitat, development should be
sited on topographically more gentle areas of the site and the west-facing
slopes and ledges protected. This would effect protection of the spotted
wintergreen population as well as some of the largest trees onsite. The
applicant's consultants should refer to Biodiversity Assessment Manual for
the Hudson River Estuary Corridor (Kiviat and Stevens 2001) for further
considerations regarding habitat assessment.
Kiviat, E. & G. Stevens. 2001. Biodiversity assessment manual for the Hudson River estuary corridor. New York State Department of Environmental Conservation, New
Paltz, New York. 508 p.
Table 1. Occurrences of rare plant species at the proposed Hillcrest Commons
development site, Towns of Carmel and Kent, Putnam County, New York. Galium concinnum (shining bedstraw) = New York State
Endangered. Agrimonia parviflora (small-flowered agrimony) = New York
Natural Heritage Program Watch List. Carex crawfordii (Crawford sedge) =