A Natural History of Millbrook Marsh, A Wetland In An Urbanizing Setting

Introduction

This paper is a compilation, synthesis and analysis of documents and research regarding Millbrook Marsh historically and up to the present. It will be used at the Millbrook Marsh Nature Center, together with the Millbrook Marsh Protection and Management Plan (Brooks et al. 1998), in protecting, conserving and managing this rare ecosystem located in an urbanizing setting.

Millbrook Marsh is a 36 ha area that includes riparian zones, palustrine emergent wetland, palustrine scrub-shrub wetland, calcareous fen, upland borders of early successional brush and forest, and pasture and farmland interspersed with woody hedgerows, surrounded by residential, commercial, agricultural, and University land use. The calcareous fen is one of the largest in Pennsylvania, despite having been reduced from approximately 2.5-3 ha to about 1 ha. The hydrology of the site includes a high water table with areas of persistent saturation, seasonal flooding and ponding, and numerous springs. Slab Cabin Run, Thompson Run, and two branches of Bathgate Spring Run flow through the site. Some springs flow first through limestone bedrock resulting in alkaline conditions at the surface. Vegetation changes over the past 50 years include disappearance of some native species of special concern, and discovery of others, in addition to an invasion of non-native species.

Millbrook Marsh, like other wetlands, performs many functions that are important to society in general, such as improving water quality, recharging groundwater and providing natural flood control, as well as supporting a wide variety of fish, wildlife and plants. In addition, it serves an educational function exhibiting the interactions and interdependencies inherent in any ecosystem. Education is one of the most important elements for effective wetland protection. By introducing the public to the ecological and sociocultural values of wetlands in general, and Millbrook Marsh in particular, the need for strong protection and restoration efforts can be appreciated and embraced. The fact that the marsh is central to a rapidly growing community provides the region and state with an outstanding opportunity to develop a model for preservation of a unique ecosystem within an urbanizing setting. It provides the vital function of filtration of the massive loads of urban runoff that are directed into the streams of Millbrook Marsh before flowing into Spring Creek It must also, though, be protected from urban runoff in increasing quantity and decreasing quality. It moderates flooding which would otherwise be more severe. In addition to the benefits it provides the State College area, it provides critical habitat to several uncommon aquatic plants, with as many as ten species of special concern being reported for the site since its discovery. Therefore, its functions and educational potential should be realized, while at the same time, it is protected from encroaching development with all of the ensuing impacts.

Approximately 25 ha of Millbrook Marsh are owned by the Pennsylvania State University, with the 11 ha remainder in private ownership. The University’s 20 ha of wetland and 5 ha of fallow farmland is under the jurisdiction of the Centre Region Parks and Recreation Authority for a 35-year lease period with a renewal option. This portion of the site has become the Millbrook Marsh Nature Center. The Millbrook Marsh Protection and Management Plan (Brooks et al. 1998), a paper concurrent with this one, recommends continued study culminating with protection, restoration, and management of the wetland in conjunction with public access and education. Considering the probability that the population of the Centre Region will increase by over 900 people annually between now and 2020, the Millbrook Marsh Nature Center will certainly become an oasis within State College, and a jewel within the Centre Region’s park system.

  On to Methods