Existing Environment
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Chapter 2 Michael Stadelmeier Existing Environment . Introduction . Physical Landscape Setting . Regional Demographic and Socioeconomic Setting . Refuge Administration . Soils, Vegetation, and Habitat Types . Wildlife Resources . Refuge Visitor Services Program . Cultural, Archaeological, and Historical Resources Chapter 2: Existing Environment 2.0 Introduction This chapter describes in detail the current physical, biological, and social environment of the Great Swamp NWR. It provides descriptions of the physical landscape, the regional setting and its history, and additionally, the refuge setting, including its history, current administration, programs, and specific refuge cultural and ecological resources. This chapter provides context for current refuge goals, issues, alternatives, and management direction, which are discussed in subsequent chapters. 2.0.1 Refuge Location and General Description The 7,773-acre Great Swamp NWR is located 26 miles from New York City within the Townships of Chatham, Harding, and Long Hill of Morris County in north-central New Jersey (map 2-1). Great Swamp NWR is situated north of Interstate 78 and east of Interstate 287. The refuge has an approved acquisition boundary that would allow for the refuge to expand to 9,429 acres (map 2-2). The refuge headquarters is located along Pleasant Plains Road in Harding Township. The refuge Visitor Center, also located along Pleasant Plains Road in Harding Township, is situated within the northwest portion of the refuge. The refuge is surrounded primarily by residential development, as well as natural areas. Natural areas adjacent to the refuge include Somerset County Environmental Education Center and Lord Stirling Park on the western refuge boundary, Morris County Great Swamp Outdoor Education Center on the eastern boundary, four Farmland Preservation properties, and one New Jersey Natural Lands Trust managed property. Figure 2-3 shows regional protected lands. An estimated 156,500 visitors came to the refuge in 2010. Although established primarily for migratory waterfowl, the refuge’s mosaic of vegetation communities, including forested wetlands, emergent wetlands, and various successional stages of uplands, provides habitats for a diversity of wildlife species (see attached wildlife list in appendix A). The refuge contains five major impoundments, encompassing approximately 500 acres. These impoundments are managed for marsh habitat that contains wetland plant communities similar to those that occur naturally in northern New Jersey. 2.1 Physical Landscape Setting 2.1.1 Physiographic and Landform Features Physiography is the relationship between a particular location and the underlying geology. New Jersey includes four major physiographic provinces, known as Piedmont, Valley and Ridge, Highlands, and Atlantic Coastal Plain. Great Swamp NWR is located entirely within New Jersey’s Piedmont Province. The Piedmont Province is a 1,600 square mile area occupying approximately one-fifth of New Jersey. It is situated in northern and central New Jersey between the Highlands Province and inner portion of the Coastal Plain Province. The Piedmont Province is generally characterized by gently rolling plains with elevations typically ranging between 200 to 400 feet above Mean Sea Level (MSL). These elevated plains are separated by a series of erodible ridges. It is predominantly comprised of mildly folded and faulted sedimentary rocks of Late Triassic and Early Jurassic age (230 to 190 million years old) (NJDEP 2005a). Long Hill, also known as the third Watchung Mountain, is underlain by basalt layers, which formed by the 2-1 Great Swamp National Wildlife Refuge Draft Comprehensive Conservation Plan and Environmental Assessment cooling of magma that was released onto the surface as lava, while the valleys and lowlands are underlain by sandstone and shale (NJDEP 2005a). Varying soil types have developed in the Piedmont Province as a result of glacial influences occurring at various periods over parts of the province. Vegetation communities within the region are more influenced by the specific hydrological regime than soil variation (Collins and Anderson 1994). Great Swamp NWR is underlain by two bedrock geology formations: Boonton Formation and Hook Mountain Basalt. Descriptions of these formations are as follows: Boonton Formation (Lower Jurassic) The Boonton formation consists of reddish-brown to brownish-purple, fine-grained, commonly micaceous sandstone, siltstone, and mudstone, in fining-upward sequences mostly 5 to 13 feet thick. Red, gray, and brownish-purple siltstone and black, blocky, partly dolomitic siltstone and shale are common in the lower part of Boonton unit. Irregular mud cracks, ripple marks, burrows, and evaporate minerals are abundant in Boonton’s red siltstone and mudstone. The formation’s gray, fine-grained sandstone may have carbonized plant remains and reptile footprints in middle and upper parts of the unit. Maximum thickness regionally is about 1,640 feet (Olsen 1980). Hook Mountain Basalt (Lower Jurassic) Hook Mountain Basalt consists of dark- greenish-gray to black, generally fine- grained and very locally medium- to coarse-grained, amygdaloidal basalt. It is comprised of plagioclase, clinopyroxene, USFWS and iron-titanium oxides. This formation contains small to large vesicles lined with prehnite. This unit consists of at least two, and possibly as many as three major flows. The base of the lowest flow within this basalt is highly vesiculated. Hook Mountain Basalt’s maximum thickness is about 360 feet (Olsen 1980). In addition to the two bedrock geologic formations, 14 surficial geology units are mapped as overlying the bedrock within the approved refuge acquisition boundary. Table 2-1 below identifies and describes the mapped surface geology units. These surface units are important in our understanding of the glacial and post glacial natural history of the refuge (Momsen, 2007). 2-2 Chapter 2: Existing Environment Map 2-1. Refuge location 2-3 Great Swamp National Wildlife Refuge Draft Comprehensive Conservation Plan and Environmental Assessment Map 2-2. Refuge Acquisition Boundary 2-4 Chapter 2: Existing Environment Map 2-3. Regional Conservation Lands 2-5 Great Swamp National Wildlife Refuge Draft Comprehensive Conservation Plan and Environmental Assessment TABLE 2-1: SURFICIAL GEOLOGY OF GREAT SWAMP NWR1 Symbol Geologic Name Description2 Sand, pebble-to-cobble gravel, silt; brown, yellowish-brown, gray; moderately sorted, stratified. As much as 15 Qaf Alluvial Fan Deposits feet thick (estimated). Sand, silt, clay, pebble gravel, locally pebble-cobble gravel; dark brown, brown, reddish-brown, gray; moderately Qal Alluvium to well sorted, stratified to massive. Contains variable amounts of organic matter. Locally, in and downstream from urban areas, contains demolition debris and trash. As much as 15 feet thick. Interbedded colluviums as i n units Qcg, Qcb, Qcbl, and Qcsl, a nd alluvium consisting of d ark brown to yellowish-brown or reddish-brown silty sand, sandy silt, to clayey silt, with beds and lag veneers of subangular basalt pebbles and cobbles (adjacent to u nit Qwb), shale chips and flagstones (adjacent to unit Qws), or Qcal Alluvium and Colluvium, Undivided subangular to subrounded cobbles and boulders of gneiss (adjacent to unit Qwg). As much as 15 f eet thick. Lag deposits dominate in steeper reaches of valleys. Fine sediment, with variable organic matter, dominates in gently sloping reaches. Reddish-yellow, reddish-brown, light gray, very pale brown clayey silt to silty clay, minor fine sandy silt, with few subangular basalt pebbles. As much as 10 feet thick, but generally more than 3 feet thick. At foot of long, gentle Qcbl Basalt Colluvium, Silty Phase slopes or at distal edge of aprons of block colluviums. Deposited in part by groundwater seepage. Occurs discontinuously along lower parts of most slopes on basalt bedrock. Very-fine to fine sand, silty fine sand; yellowish-brown to very pale brown; unstratified to weakly stratified. As much as 5 feet thick. Thin, patchy windblown silt and fine sand occur elsewhere in the quadrangle, particularly Qe Eolian Deposits in the Great Swamp lowland and the Dead River valley. Laid down shortly after postglacial lakes drained, when wind entrained newly exposed silt and fine sand from the lake bed and terrace surfaces and deposited it on adjacent uplands. Thin deposits of Eolian sediments (Qe) overlie the weathered basalt unit (see Qe d escription above). Qwb – Reddish-yellow, reddish-brown, light gray, to yellowish-brown clayey silt, silty clay to clayey coarse sand with some to many angular pebbles and cobbles of basalt and , in places on Second Watchung Mountain, gabbro. Qe/Qwb Eolian Deposits Weathered Basalt Most clasts have weathering rinds. Inclu des mixed clast-and-matrix sediment, fractured rock ru bble, and saprolite that preserves original rock structure. G enerally less than 10 feet thick over fractured, slightly weathered bedrock, which may be as much as 60 feet thick. Silt, clay, minor very-fine to fine sand; gray, light gray, light reddish-brown; laminated. As much as 70 feet thick. Qpl Lake Bottom Deposits Deposited chiefly during the Moggy Hollow stage. U ppermost parts may have been laid down in the Great Notch, Stanley, and Millington stages, lowermost parts in the Chatham stage. Fine-to-coarse sand and pebble-to-cobble gravel, minor silt an d very fine sand. As muc h as 7 0 feet thick. Qpmd Deltaic Deposits Includes deltas at Summit and along the front of