ECOLOGICAL SETTING

Watershed Context

 Millbrook Marsh is located approximately in the geographic center of the Spring Creek Watershed (Map 2 - Spring Creek Watershed), within the ecoregion known as the Ridge and Valley section of the Appalachian Mountains.  Bathgate Spring Run and Thompson Run flow through the marsh leading into Slab Cabin Run, which then joins Spring Creek a short distance from Millbrook.  Spring Creek, which begins on Tussey Mountain and ends in Milesburg, is a tributary of Bald Eagle Creek.  Spring Creek and 6 other major tributaries contribute to Bald Eagle Creek before it enters the West Branch of the Susquehanna River, the primary river supporting the Chesapeake Bay.

Climate

The climate of the region is considered to be a humid continental type.  Precipitation is ample, with an average of about 1016 mm (40 in) annually.  About half of that falls as rain during the 166 day growing season.  Winter months usually bring 762 to 1524 mm (30 to 60 in) of snow.  Temperatures are generally below 0° Celsius (32° Fahrenheit) from November through March, but very seldom reach below 17.7° C (0° F).  From June through August, the temperature is usually in the upper 20’s Celsius (low 80’s Fahrenheit) during the day and near 15° C (60° F) at night, with about 15 hr of sunlight per day.

Description

 Millbrook Marsh comprises of approximately 36 ha that includes riparian zone, palustrine scrub-shrub and emergent wetland, calcareous fen, upland borders composed of early successional brush and forest, and about 5 ha of pasture and farmland with interspersed woody hedgerows (Figure 2-1).  Parts of the wetland include 11 ha in private ownership.  The pasture, farmland, and 20 ha of wetland make up the Millbrook Marsh Nature Center.
 Millbrook Marsh is bordered on two of four sides by urban development along Routes 322 and 26 (Map 1, Map 3).  Puddintown Road borders the site along the western and northern boundaries, with an upland buffer consisting of residential areas and farmland.  Springs emerge from the adjacent private farmland behind the residences.  Two small spring fed streams flow into the Millbrook Marsh Nature Center site at the northwest corner and then merge.  This stream flow, known here as Bathgate Spring Run (Figure 2-2), travels through a field and an emergent wetland area at the bend in Puddintown Road, finally joining with Thompson Run just above its confluence with Slab Cabin Run.  This section seems to be one of the least affected at this time by the surrounding urban development which is influencing much of the rest of Millbrook Marsh.
 
 
 

  Across the road from the Farm 12 building complex, along the western edge, is one commercial site, a small dairy distribution facility,.  A well established residential neighborhood known as Bathgate is across Puddintown Road.  Over the hill from the private farm to the northwest of Millbrook Marsh is a stormwater detention pond designed to hold the stormwater runoff from the University land, particularly from the Beaver Stadium parking areas and construction sites adjacent to the Bryce Jordan Center.

 The southern boundary includes a small single family residential area behind the commercial development on Route 26 (Figure 2-3).  Along Route 26, known locally as East College Avenue, are small businesses, restaurants, a convenience store, gas station, hotel, and the College Township Building.  Parts of the marsh have been covered with fill to enable some of the development, including the residential section between the commercial development and the wetland as well as the College Township building.  There are both commercial and residential developments on the other side of East College Avenue, including a car dealership and a building supply company. At times of flooding or heavy precipitation, the runoff from these sites and others has a significant impact upon Millbrook Marsh (Figure 2-4).  This area on East College Avenue frequently becomes inundated with stormwater (Map 2, Map 4).

 The remaining side, the eastern border of the site, is bounded by a paved bikeway and footpath leading from the northeast corner of Millbrook Marsh under the Route 322 overpass to the southeast corner.  At lower elevations the path follows Slab Cabin Run.  Downstream of Millbrook Marsh it continues along Puddintown Road to Spring Creek Park.  The path also serves as a connection to and beyond Slab Cabin Run Park, on the south side of East College Avenue, with one of the few remnant stands of old growth trees in the area.  For some reason this small area of native Oak/Sugar Maple/Basswood was not cut during the Juniata iron era.  The trees, averaging 24 m high or more, are estimated to be between 150 and 300 years old (PennDOT 1981).  Beyond the path is Route 322, a 4-lane highway, and just beyond that is the developing Clover Highlands neighborhood, including both residential and some commercial development, primarily office buildings.
 
 
 

 There are various levels of disturbance in Millbrook Marsh, ranging from minimal to severe, and a range of time elapsed since disturbance.  One area that has had minimal impact contains mostly palustrine emergent wetland and is approximately 6 ha (15 ac) in area (Figure 2-5).  This portion of the marsh is bounded by Slab Cabin Run on the east, Thompson Run on the west, and a treeline north of the housing development along Route 26 to the south (Urban 1996).  It is dominated by cattails (Typha spp), sedges (Carex spp.), and rushes (Scirpus spp.).
Adjoining the central emergent wetland area is the calcareous fen.  The approximately 1 ha area within Millbrook Marsh represents a sizable example of a calcareous fen in Pennsylvania, one of the rarest types of ecological communities found in Centre County (Stack et al. 1991).  It is dominated by sedges and supported by a steady flow of groundwater filtering through the limestone bedrock, with numerous small springs emitting water along the southern edge of the fen.  At this edge there is a distinct boundary between fen and upland vegetation.  It is probable that the fen boundary is also the terminus of added fill (see Chapter 4).  It is also possible that part of the fen has been covered, but persists nonetheless (PennDOT 1981).  Interpretation of historical photographs indicates that possibly only two thirds of the original fen exists at this time (see Chapter 5).  The spring water flows northward, supporting the fen vegetation.  It progressively fades to become indistinguishable from the remainder of the emergent wetland, and as such, there is no clearly visible boundary between the fen and the emergent wetland on the northern edge.  In a study of calcareous fens in Pennsylvania (Western Pennsylvania Conservancy 1995), the fen in Millbrook Marsh was classified as part very wet open fen, part wet open fen, and part wet shrub fen.  As many as 10 species of special concern have been reported for the site, although not all have been reconfirmed within the past 10 years.  Additional rare species are believed to exist and could be revealed by further study.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Figure 2-5  Palustrine Emergent Wetland between Thompson Run and Slab Cabin Run.  July 1998.

 An area with greater disturbance occurs within the boundaries of Slab Cabin Run to the west and the paved path and Route 322 to the east.  It is approximately 6 ha in size and was a cattle pasture in 1971.  It seems that it was abandoned and allowed to revert to its current condition, consisting mostly of shrub species such as alder (Alnus spp.), willows, (Salix spp.), and dogwoods (Cornus spp.) intermixed with several large elm (Ulmus spp.), and black willow (Salix nigra) trees, as well as grasses and grasslike species (Carex spp. and Scirpus spp.) (Urban 1996).

 Thompson Run enters the site at the southwest corner and converges with Slab Cabin Run in the middle of the marsh.  Population increases in the State College region and continued development are causing increases in stormwater input into Thompson Run.  This has resulted in scouring of the creek bed, causing increased siltation further downstream in Thompson and Slab Cabin Runs.  Water velocity increases due to the scouring, which in turn results in more scouring. Turbidity is also increased, especially during storm events.  Due to these factors, fish populations have decreased, and some fish species are also no longer spawning in this area of Thompson Run, as they were as recent as 5 years ago (N. Deno, pers. comm.).  According to local fishermen, fish populations may have gradually decreased in Slab Cabin Run also over the past 10 years .

Land Use On-Site

 In recent years, land use within Millbrook Marsh has been varied.  Fishing has persisted throughout the years on mainly a "catch and release" basis for at least the past 20 years.  There are several informal foot paths used mainly by anglers, and less frequently, by hikers.  A path along Puddintown Road, on the northern edge of the site, from the Route 322 overpass to the tractor path leading to the barn is commonly used by joggers.  Since the summer of 1997, a slightly meandering path has been mown to take the place of the route the joggers used, directly beside the road.  The new path winds through some early successional growth of shrubs and young trees, more like the path proposed in the Circulation and Access Plan for the Millbrook Marsh Nature Center (Map 4).  Two tree stands erected by hunters exist in the southeastern portion of the site.  Residents of the adjacent neighborhoods frequent the marsh for walks and enjoyment of nature.  On the 5 ha section previously known as Penn State's Farm 12, the pasture areas have been used by horses and the farmhouse was and is still a leased residence.

 In the more distant past, a portion of the marsh used for a small scale farming operation.  The area surrounding the Quonset hut, including parts of what is now the Mt. Nittany Expressway, was used to raise vegetables and fruits.  Slab Cabin Run was bridged to allow access to the interior where more of the wetland was used for farming.  This ended in 1981, when the land was no longer leased due to plans for the highway.

 Other less anthropocentric land uses include flood control, sediment control, preservation of flora and fauna, erosion control, wildlife habitat, habitat for threatened, rare or endangered species, water quality and water supply (Brooks 1989, Richardson 1994).

 In progress now is the conversion of 25 ha (62 ac) of Millbrook Marsh into the new Millbrook Marsh Nature Center, which includes 5 ha of what was known as Farm 12 in the past.  For the past 2 years renovations have been made on some of the outbuildings of the farm.  The Millbrook Marsh Nature Center Advisory Committee meets in the newly renovated barn about once monthly during the warmer seasons.  Plans for the Nature Center are only approximate at this time, though construction of a water permeable gravel parking area will probably begin in the summer of 1998.  The proposed paths, boardwalks, bridges, and parking areas have been designed to afford the most benefit to visitors to the marsh and residents of the Bathgate neighborhood, and to cause the least impact on the fragile environment (Map 4).  Present and future land uses on the Farm 12 section have also been established (Map 5).  Management zones have been determined to delineate the amount of protection needed in each area of the marsh (Map 6).  The Protection and Management Plan for Millbrook Marsh (Brooks et al. 1998) characterizes and documents the current ecological conditions of the site and proposes management strategies to protect and restore the natural and cultural features of The Millbrook Marsh Nature Center.  If possible, all or most aspects of the 25 ha Nature Center will be in keeping with the recommendations set forth in the Millbrook Marsh Protection and Management Plan.  The exception to this is the possibility of the Bathgate Spring Run section of the marsh.  It is possible that water from the stormwater basin at Penn State will be piped into Bathgate Spring Run at the bend in Puddintown Road across from the dairy.  The probability that this will occur has prompted the Millbrook Marsh Advisory Committee to consider various alternatives such as moving Bathgate Spring Run so that it can be preserved from damage by large amounts of high velocity stormwater.
 Several areas within Millbrook Marsh have been used as reference wetland and study sites by Penn State faculty and graduate students.  A small pond is proposed for one area on the Farm 12 portion of Millbrook, to afford another study site for classes and Nature Center visitors (Map 5).

The site offers continued avenues and areas for recreation, education and research.  Activities could include birding, photography, painting, picnicking in some areas, restoration including long term studies of restored wetlands, studies of human impact, stormwater impact research, flora and fauna inventories, invasive plant removal and replacement research, endangered species and rare ecosystem research (propagation and reintroduction of extirpated, rare, threatened or endangered species), among others.  The possibilities are many with this particular wetland site.