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NATURAL RESOURCES INVENTORY: INTERSTATE PLANNING PROJECT
Prepared by:
Prepared for: Agency of Natural Resources December 31, 2002
INTERSTATE PLANNING PROJECT
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2.0 General Approach 1 3.0 Methods 2-6 4.0 Assessments for Significant Natural Resources ………………………………
6-14 5.0 Resource Maps ……………………………………………………………………… 12 6.0 Conclusions …………………………………………………………………………
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INTERSTATE PLANNING PROJECT
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Table #2: Streams Summary Data ……………………………………………………. 2 Table #3: Wildlife Habitat Summary Data …………………………………………….. 3 Table #4: Upland Natural Communities Summary Data ……………………………. 3 Wildlife Habitat Summary Data Metadata …………………………………………….. 4-5 US EPA: Listed Water Information for Adams Brook …………………………….. 6 Vermont DEC Biomonitoring Data for Adams Brook ………………………………
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INTERSTATE PLANNING PROJECT
The inventory project has two primary objectives: 1. identification and assessment of significant natural resources; and 2. creation of an ArcView shape file and tables for the study area. The project was conducted over a fourteen-month period, October 2001 through December 2002. This report documents the findings of the inventory project at the Randolph interchange. 2.0. GENERAL APPROACH The first phase of the project consisted of building a GIS database for the study area. The study area was defined as an area of approximately 1.4 square miles around the Exit 4 interchange. Existing digital databases (Vermont Significant Wetland Inventory maps, SCS soil surveys, USGS topographic maps, recent orthophotography, wildlife databases, and Natural Heritage maps) and local knowledge of "special places" were used to preliminarily identify and map potentially significant natural resources in the study area. The identified resource areas were grouped into four categories: wetlands, streams, wildlife habitat, and upland natural communities. The preliminary map of natural resource areas, in the form of an ArcView shape file, was used to focus field investigations. Property owners of parcels containing the potentially significant natural resources were contacted for follow-up field evaluations. Field investigations were conducted on parcels for which landowner permission was obtained. Field data was used to more accurately delineate the boundaries of the natural resource areas for the final ArcView shape files, and to broaden the assessment of the identified resources. Final maps, in the form of ArcView shape files, were created showing the location and approximate boundaries of wetlands, streams, wildlife habitats and upland natural communities in the study area. Assessments were conducted for all of the identified natural resources and narratives included for significant resources. Narratives included functional assessments and discussion of biological condition, noted impairments, and surrounding land uses. 3.0 METHODS The following methods are used to conduct the Natural Resources Inventory. 3.1 Preliminary Identification of Natural Resource Areas: Development of GIS A comprehensive review and interpretation of all available digital and paper databases as well as review of local testimony regarding "special places" was conducted to identify potentially significant natural areas in the Randolph interchange area. The following digital databases were acquired for the study area: · Vermont Significant
Wetland Inventory maps; The digital databases were incorporated in an ArcView platform (GIS) allowing for analysis of multiple data layers at the study location. Natural resource areas, including wetlands, streams, wildlife habitats, and/or natural communities, were preliminarily delineated from the GIS analysis. From the preliminary data, potentially significant resource areas were targeted for field investigation. In addition to the GIS review, the preliminary identification process involved meeting with the Randolph Conservation Commission to acquire a local perspective on the natural resources in study area. The meeting with the Conservation Commission took the form of a brainstorming session, with maps used as a note board. The Conservation Commission marked on the maps potentially significant areas based on local knowledge, such as good hunting locations or road crossing locations commonly used by animals. This information was incorporated in the preliminary Inventory Map for the study area. 3.2 Landowner Permission Digital parcel data for Randolph was used to identify the landowners in the approximately 1.4 square mile area around the interchange. Landowners in this area were contacted via a letter and asked permission for field analysis of their property. Arrowwood Environmental, LLC worked in concert with the Randolph Conservation Commission to obtain landowner permission. The landowner permission request forms were mailed in November 2001, with much help from the administrative staff in the State Wetlands Office. Of the 55 mailed, responses from 15 landowners were received for a ~27% response rate. The results of the mailing are summarized in the following table. Study Area # Forms Mailed # Respondents Positive Response Negative
Response Many landowners called to inquire about the project as a result of the mailing, providing an opportunity to educate local people about the project. Detailed field assessments of resource areas were limited to properties for which landowner permission was obtained. 3.3 Resource Assessment Criteria The focus of the resource assessments was to determine the extent of the identified natural resource, the value or significance of the resource to the community and potential threats to the resource. In addition to information interpreted from available digital and paper resources, the assessment incorporated data collected from field investigation of the study area. Field investigations of resource areas were restricted to windshield surveys from a car, assessments for parcels for which landowner permission was obtained, and stream walks. A windshield survey was conducted of the entire study area, resulting in general observations made from a car. Select properties were visited and reviewed for each of the four resource categories. Where possible, stream segments were walked. Observations from the windshield survey, field assessments and stream walks were used to help verify information interpreted from maps and digital orthophotography. Assessment criteria used for each of the four resource categories (wetlands, streams, wildlife habitat, and upland natural communities) is detailed below. 3.3.1 Wetlands Wetlands identified in the study area were informally delineated and assessed for their functions and values as wetlands. The boundary determinations of the wetland areas were based on interpretation of 1996 orthophotography, SCS soil survey maps for Orange County, National Wetland Inventory maps, and field observations when possible. Formal delineations of resource areas were not possible due to limited access. Therefore, boundary lines are meant for planning purposes only. The wetland assessment methodology integrates information about a wetland's soils, vegetation, location in the watershed, shape and size, and habitat diversity to produce a composite picture about a wetland's role in the larger ecosystem. Eight of the ten functional criteria identified in the Vermont Wetland Rules were used in assessing the wetland resources in the study area. Each of the identified wetland areas was evaluated for the presence of factors that would indicate that the wetland was serving a significant function as a productive ecosystem and/or a public resource. The Vermont Wetland Evaluation Form, US Army Corps of Engineers Highway Methodology Handbook and Golet Model Wetland Evaluation Form were used as guides for the functional assessment. Assessments involved field components when possible. Wetlands which landowner permission was not obtained were assessed remotely utilizing information available from the windshield survey and existing digital and paper databases. The target eight functions and values and functional determination criteria include the following: · Water Quality: Indicators
of nutrient removal and sediment detention were determined by
presence of potential sources of pollution within the watershed,
size of the wetland relative to the overall watershed, and presence
of persistent vegetation. The functional assessment did not include the hydrophytic vegetation habitat or threatened and endangered species habitat functions and values. An accurate assessment of these habitats requires field investigation, which was not possible for the majority of the wetland areas. 3.3.2 Streams The stream assessment criteria included the following: · Stream type (intermittent,
permanent); Field data was collected when possible, but was limited to stream segments with landowner permission and/or safe access. The macroinvertebrate assemblage description is based on a rapid assessment in the field. The field protocol involved using a kick net to collect a representative sample of the stream biota. Samples were reviewed in the field for presence and relative abundance of macroinvertebrate groups (including mayflies, stoneflies, caddisflies, beetles, true flies, and worms). Specimens were identified to a gross level of classification for general characterization purposes. 3.3.3 Wildlife Habitat The wildlife assessments include the identification of a wide variety of wildlife habitats including streams and riparian zones, ponds and shorelines, forested areas, and possible corridors providing important linkage habitats between forested or other wildlife habitats within the study area. Wildlands were characterized by size, dominant land use, forest type, the presence of roads and housing, foliage height and horizontal diversity, surface waters, structural/ledge features, and observed wildlife sign (where access was available). The following criteria were selected for use in evaluating the resource areas identified as potentially significant wildlife habitat: · Matrix (dominant land
use) The study area was divided into Wildlife Habitat Units that were un-fragmented by roads (including paved and or well-traveled dirt roads), as these features are often barriers to wildlife movement. Each Unit was thus a patch of varying size, some containing streams, wetlands and/or other natural features. Within each of the Units, existing digital databases were used to identify habitat features that are directly associated with high wildlife species diversity or indirectly associated the presence of certain species. This assessment included looking at known deer wintering areas, the presence of surface water, wetlands, and the potential for wildlife movement corridors. Field evaluations were conducted for resource areas with landowner permission. 3.3.4 Upland Natural Communities An overall ecological inventory was conducted for upland natural communities identified for field evaluation. This inventory included the identification of the dominant plant species, and an explanation of the development of the community. The condition of the community was assessed based on the amount of, and time since major human disturbances, the size of the parcel and the current condition of the community. Using these factors the community was ranked based on the Nongame and Natural Heritage Program (NNHP) criteria for the statewide ranking of significant natural communities. Historical locations of rare plants and animals in the town of Randolph were obtained from the NNHP. Sites found within the study area were targeted for a field visit to determine the current status of the population in question. In addition, areas that contain potential habitat for these species were targeted for a field visit to determine if other populations of these species exist. Field visits were limited to areas where landowner permission was obtained. The following three criteria were selected for use in evaluating the resource areas identified as potentially significant natural communities: · Landscape Context; The Landscape Context criterion was used to evaluate the condition of the landscape around the site in question. Intact natural communities that are surrounded by agricultural or developed land have the potential to have more edge habitat, contain more exotic species and to experience disturbances than sites surrounded by 100+ acres of forested land. The landscape context can therefore be used as a remote ranking factor for the quality of the community. The Ecological Significance criteria was used to remotely evaluate the resource using three broad parameters: 1) presence of a rare, threatened or endangered element as recognized by NNHP; 2) site potentially harboring an S1, S2 or S3 ranked natural community; and 3) site a non-matrix forming community type. Finally, the ownership of the land (public vs. private), the ease of access from a public road, and the presence of trails or proximity to an urbanized area were used to evaluate the potential of the resource to support educational or recreational endeavors. Due to difficulty in acquiring landowner permission, field assessments were limited. 4.0 Assessments for Significant Natural Resources The resource assessments for significant wetland, stream, wildlife habitat and upland natural community resources are detailed in this section. The assessments include determination of resource unit boundaries (shown on the attached Resource Map and ArcView shape files), functional assessment, and noted impairments and/or potential threats to the resource. Assessments for all identified natural resources are provided in the form of summary tables in the Attachment. 4.1 Wetlands Seven (7) Wetland Units were identified in the Randolph study area. The wetlands consist of both Class II and Class III wetlands, as defined by the State of Vermont Wetland Rules. Wetlands occupy approximately 7% of the study area (59 acres), ranging in size between 0.9 and 31 acres. The majority of the wetlands identified in the study area are characterized as Emergent Marshes and/or Shrub Swamps (57%). The remaining wetlands consist of conifer swamps. In general, the functional assessments show that all of the identified wetlands are significant for at least two functions and values. The majority of the wetlands were found to be significant for water quality, flood protection and open space. Only those associated with streams were likely significant for fisheries. The results of the functional assessments for all of the Wetland Units are summarized in Table 1 of the Attachment. The most significant wetlands in the study area, as related to ecological function, are the two conifer dominated areas in the northwest part of the study area. These systems are described below. The Wetland Units described below correspond to the polygon ID's in the ArcView shape file. See attached Resource Map for Wetland Unit locations. Hemlock Forest (Wetland Unit # 1) This Hemlock Forest is a large (approximately 30 acre) uneven aged forest dominated by hemlock and balsam fir. The forest is surrounded mostly by Northern Hardwood Forest and the Interstate. The forest consists of many mature trees, as well as standing and fallen woody debris. Occasional openings in the canopy contain yellow birch (Betula alleghaniensis). Overall, the canopy cover in this forest is fairly dense, around 85%, keeping the shrub and herbaceous layers sparse. Intermediate fern (Dryopteris intermedia) and Christmas fern (Polystichum acrostichoides) are the most common herbaceous plants. Though the soils are mapped as hydric soils at this site, most of the forest that could be seen did not appear to be a wetland. There were, however, many small wet depressions and seepy areas within the matrix upland forest, thus resulting in the Wetland Unit designation. It is likely that areas of the matrix forest that were not seen during this survey contain examples of the Eastern Hemlock Swamp natural community. The only access to the overall area was by walking the stream (Stream Unit #3) that bisects it. An area of flooded Conifer swamp and Alder Swamp was seen from the stream channel. The extent of these communities is unknown due to lack of access. From the limited survey from the stream channel, natural processes seem to be the main driving forces in this community, which appears to be in excellent condition. The presence of a diverse forest matrix likely provides significant wildlife habitat, including squirrels, woodpeckers, songbirds and deer. A wide variety of bird species are known to nest and breed in hemlock dominated forests including thrushes, saw-whet owls, solitary vireos and several species of warblers. Though there is a small amount of stream bank erosion along the stream that runs through this forest, the riparian zone vegetation that grows here contributes significantly to the binding of the soil and the prevention of erosion. Runoff from the Interstate, located to the east of the Unit, likely flows down the steep slopes and into this Unit. It is likely that this wetland is significant for the filtering and treating of that surface water runoff. There is currently one house on the northern end of this forest. Further residential development along the road leading to this house is a potential threat. This site may be too wet for houses or other development, but without a detailed field visit to the site, this cannot be confirmed. Emergent Marsh /Alder Swamp (Wetland Unit # 3) This approximately 8 acre wetland is located in the center of an open field which is experiencing residential development. The site is colonized by a mix of reed canary grass (Phalaris arundinacea), mash marigold (Caltha palustris) and patches of dogwood (Cornus spp.). There are areas of old field that are slightly drier and being colonized by willow (Salix spp.) and dogwood shrubs. The wetland has wildlife habitat value for deer, fox, and many species of migratory birds. Reptiles and amphibians such as the garter snake, leopard frog, green frog and spring peeper are also known to live and breed in these communities. The site also has the potential to filter water of sediment and pollutants associated with the nearby development, has an expandable basin to retain flood waters, is aesthetically prominent in the landscape, and is the center of the Wildlife Habitat Units (#4 and #5) in the area. It may also have value as a wildlife corridor for the movement of wildlife in and out of the valley in which it is situated. Further encroachment around this wetland will likely diminish many of its functions and values. It is recommended that development near this wetland be conducted outside of a minimum 50 ft buffer zone to protect the functions and values outlined above. 4.2 Streams The largest, most significant stream in the Randolph study area is Adams Brook; a permanent, waterway that runs east to west through the middle of the study area. All of the other, smaller streams in the study area are tributaries of Adams Brook. Adams Brook is described in detail below. Adams Brook (Stream Unit #1) The headwaters of Adams Brook occur within the eastern portion of the study area, just south of Route 66, and consist of an Emergent Marsh (Wetland Unit #6). The Brook flows to the west through a small area of old field and White Pine Forest before it is culverted underneath the Interstate. From that point, it flows through another old field and into a Hemlock-Northern Hardwood Forest. Before it leaves the study area, it flows through a young Northern Hardwood forest. Where the stream runs through the forests, it is well buffered. On the east side of the Interstate and near its headwaters, the stream flows adjacent to the road (Route 66) and has only a narrow, though mostly forested, buffer. Adams Brook flows west out of the study area and joins the Third Branch of the White River just east of Randolph village. The substrate of the Brook is predominately cobble. Where the stream flows through the Hemlock-Northern Hardwood Forest, the stream gradient increases and the substrate is mixed bedrock with cobble. Other than small areas of silt deposits, there are very little sediment deposits in this stream. The water is clear and odorless. The macroinvertabrate assemblage includes indicators of healthy streams, such as mayflies, stoneflies and caddisflies. There are a number of waterfalls and pools along the stream course that receive local use as swimming holes. Near the western edge of the study area, the stream nears the road and there is small private park that highlights a waterfall. This stream is on the EPA list of Impaired Waters due to general threats of contamination by nutrient runoff and human-caused sediment deposits and pathogens. The increased nutrient load in Adams Brook is most likely related to runoff from agricultural fields. An increase in sediment deposits is likely attributed to activities and development within the riparian buffer or directly on the stream banks. The potential threats to this stream include increased nutrient load from agricultural activities. The Emergent Marsh at the headwaters of this stream is located just below active agricultural fields; runoff from these fields likely occurs and increases the nutrient input into this wetland/stream system. It is not known to what extent this increase in nutrients has contaminated the stream. Both within and downstream of the study area, Adams Brook flows through or near active agricultural fields. Watering cattle directly in the stream can lead to stream bank erosion, increased sedimentation of the stream and contamination of the stream with pathogens. Maintaining and reestablishing a shrub dominated or forested buffer between agricultural activities and the stream channel (or wetlands associated with the stream) can reduce nutrient runoff into the stream system. The threats of development along the banks of Adams Brook have, up to this point, been minimal. If development is to occur near the stream, it is recommended that a minimum 50' naturally vegetated riparian zone be maintained between the development and the stream channel. This buffer zone will help to mitigate any impacts that the development may have on the stream system. 4.3 Wildlife Habitat Ten (10) Wildlife Habitat Units were identified in the Randolph study area. These areas comprise a total of about 370 acres or about 42 % of the total study area. The Randolph study area is dominated by coniferous forests, most often Eastern Hemlock Forests. Each of the Units was assessed and summary data is provided in Table 3 of the Attachment. The significant Wildlife Habitat Units are described below. Wildlife Habitat Units #1 and #6 Units #1 and #6 are riparian forests dominated by coniferous forest cover located in the southeastern portion of the study area. These coniferous riparian corridors are often rich is bird life, and provide cover for movements by other wildlife. Unit #6 is relatively isolated by roads, while Unit #1 is situated in such a way that it could perform corridor functions between the extensive woods to the west of the study area and Unit # 3. These riparian forests are often sought out by wildlife as they move about the landscape in search of food, mates, or seasonal and permanent habitat. Species such as the raccoon, fox, and even bobcat have been found to prefer habitat or movements along stream courses. Kingfisher are also found in these habitats. These areas provide fish habitat within the streams that they surround. Wildlife Unit #1 has the main branch of Adams Brook flowing through it (Stream Unit #1). Wildlife Unit #6 has a tributary to the Adams Brook (Stream Unit #7) flowing through it. Deer habitat is provided by the cover in these areas, and it is possible that sunny and warmer slopes within these Units could provide winter habitat as well. Wildlife Habitat Unit #2 Wildlife Habitat Unit # 2 is a large (approximately 85 acres) hardwood-dominated forest located in the northwest portion of the study area. Unit #2 has a stream (Stream Unit #2), good foliage height diversity, and a section of more open habitat, all of which contribute to overall wildlife diversity. The large forested area, access to other forest areas as well as the availability of more open ground habitats suggest that this Unit has a high diversity of wildlife. This area is likely to have mast producing trees and is also accessible to wildlife within the larger matrix forests (and wetlands) to the west and north. This area provides habitat for a wide-variety of birds, deer and moose, forest hawks and owls and other predators. Unit #2 is generally surrounded by forest, including shrub-dominated natural communities and Wildlife Habitat Units #3 and # 1. This is a relatively dry area and as such is vulnerable to human development. As a hardwood forest (with less natural cover and noise buffering capacity) this area is particularly sensitive to disturbances, which could result in diminishment of wildlife habitat and value to wildlife. Any development near this Unit must be carefully planned in order for this forest and it's habitat elements to continue to provide for the widest variety of wildlife. This Unit along with Unit #3 are the most important wildlife habitats in the Randolph study area. Wildlife Habitat Unit #3 Unit #3 is a relatively large Eastern Hemlock forest. This area has plenty of water available (Stream Unit #3), good overall cover, good foliage height diversity, and is located in an area that is adjacent to large forest lands to the west. The Unit does not appear on the Fish and Wildlife deer yard map, however there is likely deer over-wintering habitat present. The area is likely visited by a variety of predators, including fisher, owl, mink, otter as well as bobcat. Because this Unit is within a forested matrix, it offers many different wildlife habitat elements, such as locations where coniferous and hardwood forest meet. This Unit would be predicted to have a high level of wildlife diversity. A large number of wildlife species would be expected to use this and the neighboring Unit #2. This is one of the more important wildlife habitats within the Randolph study area. Any development directly adjacent to this forest will diminish the wildlife value of this Unit. Wildlife Habitat Unit #8 Unit #8 is an extensive (approximately 130 acre) conifer-dominated forest in the southeast quadrant of the study area. This Unit contains open habitats such as, old fields and wetlands, as well as available water (as streams) and in some areas, a relatively high foliage height diversity. This area brings wildlife north up into the core area surrounding the Interchange, as well as providing habitat for a variety of bird life. A large, but un-assessed hardwood forest is located within this Unit as well. It is possible that Unit #8 also harbors over-wintering deer habitat. Turkeys probably use the forest edges of this Unit, as do deer, fox, and coyote. Potential threats to this area are primarily in the form of habitat fragmentation. If this area were fragmented within it's interior or developed along it's eastern edge any predators or over-wintering deer that may be present might seek other habitat. It is already affected by the presence of the Interstate in terms of isolation and noise. Human pressures along the area's eastern flank would further isolate the area. 4.4 Upland Natural Communities This study area contains a number of intact natural communities, though some have been fragmented or otherwise affected by the construction of the Interstate. There are two communities at this site, both Hemlock Forests, which are considered locally significant. One is listed below and one is described in detail in Section 4.1 above. No state significant natural communities were found in the study area. Many of the communities could not be visited due to lack of landowner permission. Their condition, extent and significance could not, therefore, be determined. The Northern Hardwood Forest in the northern part of the study area (Upland Natural Communities Unit # 5) is one such site. The part in the study area is the southern tip of a much larger forest that extends northward and, eventually, to the west as well. This stand may be a significant forest but without a detailed site visit and assessment, an ultimate determination cannot be made. Hemlock/Spruce-Fir Northern Hardwood Forest (Upland Natural Community Unit #1) This is a standard example of the Hemlock Forest community that is widespread in the State. Its size (approximately 16 acres) prevents it from being ranked statewide but it is of local significance. The canopy within this forest is dominated by a dense growth of Eastern Hemlock trees that shade out growth in the understory. There are localized patches of hardwood cover that contain a more diverse understory. There are also occasional lowland areas near the stream that are dominated by spruce and fir. Frequent blow downs in the spruce and fir stands offer dense understory growth. The most important feature of this stand is the stream which bisects it (Adams Brook, Stream Unit #1). There are numerous waterfalls and swimming holes which appear to get at least limited use recreationally. At the far western end of the Brook, there is a private park that highlights one of these waterfalls. This forest appears to be in good shape and is important both aesthetically and recreationally. 5.0 Resource Map Individual ArcView shape files were created for the four resource groupings: wetlands, streams, wildlife habitats and upland natural communities. The GIS platform provides a versatile tool for ongoing analysis of the resource areas. Resource Maps are provided in the Attachment. ArcView shape files are provided on the attached CD Rom. 6.0 Conclusions The Randolph study area has a few natural communities that have local significance as natural communities. To the west, Adams Brook has waterfalls, a small rocky canyon-like structure and high aesthetic values and as such considerable local significance. The area's wildlife habitats are often conifer-dominated forested areas associated with streams and riparian zones. The integrity of these ecological systems, natural communities, and their wildlife habitats, will only be maintained through careful planning that identifies and protects important landscape features that are essential to the well-being of these resources. Protective buffers afforded these resources must be sufficient in size to adequately protect the homes, living and breeding spaces, food, and cover upon which the plants and animals of this area depend. In terms of wildlife habitats, allowing further encroachment into and around these habitats will result in the isolation of these habitats with resultant decreases in population sizes, and even the loss of species. Adams Brook and other streams within the study area can only
be protected if key areas within their watersheds are also protected.
Water quality has already been negatively impacted within certain
areas of the study area and in order for these areas to recover
streams, stream corridors and watersheds must be treated as the
sensitive ecosystems they are.
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