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NATURAL RESOURCE
INVENTORY: INTERSTATE PLANNING PROJECT
Prepared by:
Prepared for: Agency of Natural Resources December 31, 2002
INTERSTATE PLANNING PROJECT
Page
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 …………………………………………………………………………
12
INTERSTATE PLANNING PROJECT
Page Resource Map ……………………………………………………………………………
1 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
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 Berlin 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 1.7 square miles around the Exit 7 interchange. Existing digital databases (Vermont Significant Wetland Inventory maps, SCS soil surveys, USGS topographic maps, 1996 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.
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 Berlin interchange area. The following digital and hardcopy 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 upland 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 Berlin 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 Hardcopy tax maps were used to identify the landowners in the approximately 1.7 square mile area around the Berlin interchange. Landowners in this area were contacted via a letter and asked permission for field analysis of their property. Arrowwood Environmental worked in concert with the Berlin 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 82 mailed, responses from 13 landowners were received for a ~16% 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.
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 1999 orthophotography, SCS soil survey maps, 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.
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 Berlin 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.
Nineteen (19) wetland systems have been identified in the Berlin 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 11% of the study area (125 acres), ranging in size between 0.6 and 44 acres. There is a diverse array of wetland types in the study area including Emergent Marshes, beaver ponds, Spruce-Fir-Tamarack Swamps, shrub swamps, a Cattail Marsh and a small Sedge Meadow. The most abundant type of wetland is the Emergent Marsh, which occupies approximately 87 acres within the study area. Four wetlands (Wetland Units # 10,11,12 and 16 ) may not be exceptional in terms of functions and values but are worthy of note because they are likely to receive development pressure. They all occupy old-field and open areas around Berlin Corners. They are mostly shrub swamps dominated by scattered willow (Salix spp.) and dogwood (Cornus spp.) shrubs. The herbaceous vegetation consists of sedges (Carex spp.) in the wetter areas and other mixed forbs in the drier areas. One community, Wetland Unit #10, lacks shrubs and is best characterized as a small Sedge Meadow. These sites were not visited due to lack of access and may contain upland areas within them. The wetlands identified in the study area are, from a natural community perspective, generally in Fair to Poor condition. Many of them have been impacted by road construction, which often disrupts the local hydrology and floods or drains the wetland. Many have also been colonized by invasive plants such as purple loosestrife (Lythrum salicaria) and reed canary grass (Phalaris arundinacea). While these factors often degrade the overall quality of the natural community, these wetlands are valuable in that they are located within a semi-urban area. Within this area they still offer important areas for wildlife, pockets of plant diversity and important hydrologic functions. In general, the functional assessments show that all of the identified wetlands are significant for at least one function and value, and most of the wetlands are significant for more than two functions and values. Only Berlin pond was rated as significant for recreation and education. The high significant rating of this wetland in general, however, takes into account the entire pond, not just the small area that exists within the study area. The results of the functional assessments are summarized in Table 1 of the attachment. Wetland Unit #2 This wetland consists of an Emergent Marsh along the banks of the Berlin Pond stream (Stream Unit #2) and the Berlin School stream (Stream Unit #1). Along the banks is a dense colony of reed canary grass (Phalaris arundinacea). This is an invasive plant that tends to choke out native vegetation. Its presence on the banks of these streams, however, may aid in erosion prevention by providing persistent vegetation that binds and stabilizes the soil. The most significant area of this wetland is at the confluence of the two streams mentioned above. Here, the streams become sinuous and open water is interspersed with islands of diverse native vegetation. This area provides good wildlife habitat for animals such as waterfowl, muskrat, beaver, many species of songbirds, otter, and many species of frogs. The sinuous nature of the streams here coupled with the low topographic position relative to adjoining uplands provides storage, treatment and slow release of surface water, rain, snowmelt, groundwater and floodwaters. This wetland is therefore likely significant for floodwater protection. This wetland is also readily visible from the PaineTurnpike Road and provides open space and has prominence as a distinct feature in the surrounding landscape because it contrasts with the matrix upland forests and agricultural land. The agricultural land to the south of this wetland may pose a threat of increased nutrient runoff into the wetland and stream. In most places, however, it appears that there is a sufficient buffer between and agricultural field and the wetland. The biggest threat to this wetland is an increase in residential or commercial development around it. If such development is to occur, it is recommended that a minimum 50' naturally vegetated buffer be maintained between the development and the wetland boundary. Wetland Unit #4 This wetland is located in the northern portion of the study area and has been identified as a Locally Significant Natural Community. This is the largest, most significant wetland complex in the study area. This site was not visited during the inventory due to lack of access. Based on review of available information, it appears to contain many different natural communities including a Spruce-Fir Tamarack Swamp, an Emergent Marsh, Open Water and an Alder Swamp. This appears to be a beaver influenced wetland system. It contains approximately four distinct beaver ponds, many in differing stages of succession. The wide variety of habitats at sites like this provide for a large amount of plant species diversity and significant wildlife habitat. Without a field-visit to the site, the distribution, abundance and significance of these natural communities is unknown at this time. Taken as a whole, however, these communities certainly form an interrelated wetland complex that is locally significant. The large number of open water areas and the low topographic position relative to the adjoining uplands provides storage, treatment and slow release of surface water, rain, snowmelt, groundwater and floodwaters. This water storage likely lowers flood heights and reduces erosion downstream making this wetland significant for floodwater control. Much of this wetland is currently surrounded by forest. If further development is to occur near this significant wetland, this forested buffer should not be compromised. Due to the significance of this area, a forested buffer of at least 100' is recommended for all areas of this wetland.
The Berlin study area contains two significant streams, the Berlin
School Stream and the Berlin Pond Stream, both of which terminate
at the Winooski River. Each of the streams is discussed in detail
below. Data collected for each of these segments in the study
area is included in the attached Table 2, Streams Summary Data.
This stream runs nearly the entire length of the study area starting by the airport and ending at its confluence with the stream that drains Berlin Pond. South of Route 62, the stream runs through Alder Swamps, and an old field. Here, it is a wide, shallow stream with primarily a cobble substrate. The cobble substrate is silted in with sands and silts in about 10% of the streambed area. The Alder Swamp provides dense shade for this stream, adding leaf litter, keeping water temperature low and providing cover for wildlife. Both stonefly and mayfly larvae were found in the macroinvertebrate assemblage. The stream at this point appears to be in Fair condition. North of Route 62 the stream flows through a flooded Hardwood Swamp, a Red Spruce-Northern Hardwood Forest and an old field. At its confluence with the Berlin Pond Stream, it becomes much slower and the channel becomes sinuous. The substrate is mostly organic mucks and the area forms a Shallow Emergent Marsh. Plants such as arrowhead (Sagittaria latifolia) and rice cut-grass (Leersia oryzoides) are interspersed with areas of open water. Plant diversity in this area is high and there is evidence of beaver activity and use of the area by waterfowl. Potential threats to this stream include further development in the field south of Route 62. If further development occurs here, a minimum 50' wide buffer should be retained along the border of the stream. In the areas of the old field, trees and shrubs should be allowed to reestablish within the riparian zone. Immediately north of Route 62, the stream is buffered by a wetland; further development within the stream buffer zone in this location is unlikely. The large parking lot that is associated with the Staples shopping center has created impervious surfaces that could potentially drain gas, oil and their heavy metal constituents into the stream system. Further development in this area should be planned in such a way that this does not occur. Runoff from the parking surfaces should drain into the constructed wetland to the north of the parking lot. Berlin Pond Stream (Stream Unit #2) This stream drains Berlin Pond and is the largest stream in the study area. South of Route 62, it flows out of the Pond, through a narrow band of Northern Hardwood Forest and a small Emergent Marsh. The hardwood forest is fairly young but offers shading to keep water temperatures low and nutrient input through leaf litter. The stream in this area has a cobble substrate and appears to be in good condition. North of Route 62, the stream runs through a large beaver influenced wetland, through an area of upland forest and then back into an Emergent Marsh wetland. The beaver influenced wetland changes the character of the stream dramatically creating a more sinuous channel pattern, increasing the organic matter input into the stream water and increasing the water temperature from lack of canopy cover. When the stream enters a forested matrix once again, the substrate reverts to cobble with some areas of sediment deposits. The channel substrate is often covered with algae in this segment. The gradient of the stream is the highest here and mayfly, stonefly and caddisfly larvae were found in the macroinvertebrate assemblage. When the stream crosses Paine Turnpike Road, the gradient decreases, the channel widens and flow decreases. The banks are covered by dense colonies of the invasive plant, reed canary grass. Small, scattered areas of Alluvial Shrub Swamp exist on both sides of the stream. These areas also seem to be colonized by reed canary grass. The amount of sediment deposits in this area increase to about 20-30% of the stream bed area. Potential threats to the integrity of this stream include residential development along its banks and within the riparian zone. Wherever residential lawns and agricultural fields abut this stream course, there is the potential impact of increasing the nutrient load into the stream system. This threat already occurs in several places along this stream. Ideally, forested or shrub buffers are maintained between lawns and agricultural field and streams. This buffer can act not only to filter out the increase in nutrients but also can stabilize the stream bank and provide a travel corridor for wildlife. For these reasons, a buffer zone of 50'-100' should be maintained between this stream and any further development that is to take place near the stream channel. Copley Hospital Stream This steam appears on the USGS topographic map as an intermittent stream. Within the study area, however, there is no defined channel or stream bed. 4.3 Wildlife Habitat There are nine (9) Wildlife Units identified at the Berlin interchange. These units comprised a total of approximately 480 acres of the study area (about 42 % of the study area). Wildlife habitats in Berlin are largely dominated by forest and wetland communities, many of both are largely dominated by coniferous cover. Wildlife Habitat Unit #1 Wildlife Unit #1 is the largest habitat in the study area at over 150 acres in size. This area of mixed deciduous and coniferous forest growth likely has a deer yarding area, rock/ledge structure as well as several large wetlands, with open water within its boundaries. Most predators, including black bear, are likely found in this Unit at some stage in their yearly movements. The wetlands and beaver complexes may harbor brook trout and provide amphibian habitat. Unit #1 is connected to wild areas outside of the study area to the north and west. This Unit contains the most interior forest habitat within the study area. It includes habitat for large area-sensitive species of wildlife such as moose and deer as well as riverine species such as mink, otter, waterfowl and shorebirds. Song birds such as the ovenbird, owls and pileated woodpecker may live here if areas of larger trees are present. The diverse landscape including upland and wetland communities also contains significant habitat for a wide variety other song birds especially if the area contains forest in several age classes. Encroachment into this Unit will likely lead to the loss of wide-ranging species, forest interior species, and some of the water dependent wildlife that currently use this Unit. Wildlife Habitat Units # 2 and 3 Units # 2 and 3 are situated in more highly developed locations than the other Wildlife Units. Their overall value to wildlife is most likely already diminished. These Units however, contain water-based wildlife such as amphibians, shorebirds and waterfowl. These areas provide important wildlife habitat to the more urban core around the hospital center and Berlin Mall. These wetlands/wildlife habitats that are close to urbanized area, the Interstate, and the off-ramps, provide excellent opportunities for wildlife viewing. The presence of the Interstate, it's noise and isolating mechanisms within Units #2 and #3 have already compromised wildlife values. Any further encroachment of human activities into these areas will lead to fragmented habitats where only common species (such as the fox, raccoon and skunk) will be found. Wildlife Habitat Unit # 7 Unit # 7 is connected by water to Berlin Pond and is habitat to mink, otter, amphibians, shorebirds and waterfowl. These species all use the waterway extending north from the pond. Fish and other aquatic life are also likely present in these waters. A family of otters, a beaver, and deer sign was found in Berlin Pond itself and the aquatic species may very well use this connecting area. The use of these areas by otter, certain shorebirds, and perhaps other species, is currently threatened by development along the Berlin Pond northern extension. This Unit is already fragmented; continued encroachments by housing, roads, and/or development would have negative consequences for wildlife within the Unit. In some cases species may abandon the area, and in others, populations could decrease as human activities increase within the Unit. Wildlife Habitat Units # 8 & 9 Wildlife Habitat Units # 8 & 9 are relatively large forested areas (over 100 acres combined) that are connected to the west by forested wildlife habitat. These areas are situated within the western side of the Unit, and just outside of the study area are extensive deeryards, mapped by the Fish and Wildlife Department. Both of the Units likely contain some over-wintering deer habitat, they contain wetlands, a mix of deciduous and coniferous forest as well as some relatively open areas. Units # 8 and # 9 probably contain a mix of open ground and forest interior species, providing for a high overall biodiversity. These areas are likely frequented by wide-ranging predators such as fisher, perhaps bobcat, owl, and perhaps even black bear entering the habitat from the western matrix forests. 4.4 Upland Natural Communities There were no state significant upland natural communities identified
in the Berlin study area during this inventory. The one locally
significant community is described above in the Section 4.1. The
upland natural communities within the study area consist mostly
of White Pine-Northern Hardwood and Spruce-Fir Northern Hardwood
Forests. The larger intact forests exist on the western extent
of the study area. These, however, are mostly fragmented by agricultural
fields and the Interstate. The forests in the eastern part of
the study area are also fragmented, largely by development and
agricultural fields. Individual ArcView shapefiles 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. 6.0 Conclusions The Berlin study area contains a wide variety of significant resources that play an important role in both the aesthetics of the area and the healthy functioning of the ecological landscape. Among these resources, is a wide variety of important wetlands. These wetland systems are not only prominent features in the landscape, but are diverse both ecologically and in the functions that they perform. Significant wildlife habitat exists (including some important interior forested habitat) in the northwestern part of the study area. Many of the habitats found in the Berlin study area have been affected in some way by the encroachment of residential and commercial development. Further development could be detrimental to these ecological systems. Protective buffers afforded these resources are, in many cases, the best way to mitigate the effects of development. 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. An inventory such as this can therefore play an important role in the planning process. By understanding the significant resources in this area, development can be managed in such as way as to have the least possible impact on the ecological integrity and rural character of the area.
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