Liberty State Park is an extraordinary and unique public resource. With the Manhattan skyline, the Statue of Liberty and Ellis Island as a spectacular backdrop, it is one of the nation's most visited state parks. In the center of the park there remains approximately 251 acres, the former railroad yard, which is undeveloped. Much of the area has been re-colonized by various plant communities. These communities represent unique associations of both endemic and non-native species that can be considered the result of the cultural events that have taken place during the past several centuries. This post-industrial landscape represents the leading edge of the movement to convert urban brownfields into open green space. However, before such restoration initiatives can be undertaken, and reasonable objectives established, a clear understanding of these new ecologies and the risk associated with the contaminated soils has to be undertaken.

While numerous studies over the past several decades have described the impairment of ecological integrity associated with urbanization, few attempts have been made to clearly define and quantify the ecological functions and services of urban green-space. Those studies that do attempt to define urban ecology generally use biodiversity, as the primary metric. They take the traditional approach of comparing an index of measured urban diversity to a hypothetical historic reference. Couched in terms of ecological resilience, they generally prescribe to the theory that species richness can be positively correlated with ecosystem stability and, to a lesser degree, function. The Urban Forestry Lab at Rutgers State University seeks to further define ecological function as a product of assembly theory, focused on urban novel communities where their vitality may not be connected to species richness. We attempt to establish new references, associated with the urban environment that focus on the ecological function such as, carbon and nitrogen cycling, hydrology and the mitigation of those contaminants typically associated with the urban soils of novel urban assemblages. Novel assemblages, often referred to as "urban wildlands," appear to function in spite of the environmental stressors of the urban environment. They developed unique patterns of species diversity and distribution; models of primary productivity and carbon sequestration that are driven by threshold tolerances to soil conditions, and can develop along nontraditional community trajectories.

Study
The ecological risk associated with uptake and transfer of various contaminants appears not to follow traditional bio-magnification scenarios. Our research has documented the relationship between soil metal load and plant species distribution, primary productivity, diversity and assemblage trajectory. In addition, we have studied the transfer of soil metal contamination to insects at several trophic levels and to several species of birds. The emerging picture is one where species that are adapted to the stress of metallic soils often exclude or sequester contaminants in a way that isolates them and inhibits transfer within the food chain. In-spite of high concentrations of Arsenic and Lead in the soils of Liberty State Park, the naturally colonized plants did not exhibit any significant concentrations within their root, stem or leaf tissue.

Process
A broad-based, goal-driven approach was used to develop the General Management Plan for the site. The planning committee, which consisted of professionals from the New Jersey Park Service, scientists and community organization representatives, spent two years discussing the best use for the area. After examining many alternatives, the committee decided the greatest good for the greatest number of people would be to keep it as an urban wildland. In doing so, the planning committee identified two basic premises; first that the various plant communities which have re-colonized much of the site, like the surrounding community of people, are diverse and have origins throughout the world. This diversity is further enhanced by the rapid rate of natural succession (change inherent within any ecosystem). Hence, there is ecological and aesthetic value in the existing novel plant communities. The second premise was that the soils of the area consist of fill brought in by the railroad companies between 1860 and 1919 to stabilize the surface. Much of it is non-consolidated material resulting from construction projects in Manhattan, or refuse from throughout New York City and the surrounding area. It is classified as historic fill and has some limitations. Allowing public access via the creation of a trail system will have to creatively combine soils mitigation, boardwalk construction, plantings and some fencing to ensure the safety of pedestrians through the site. However, the site should maintain its urban ecological character.

Landscape architect Margie Ruddick was brought in to develop a landscape plan for the site. Under her guidance, the plan focused on telling the story of a transformational landscape, a former rail yard now an urban wildland oasis. Visitors would walk along old rail lines that evoked visions of the industrial revolution while they looked for the hundreds of species of birds that migrate through the park in the fall. They would use the bird blinds to peer at the nesting waterfowl in the created wetlands during the summer and they would ride sleighs on the hills built with the fill material from the creation of those wetlands during the winter.