Derelict land commonly found in metropolitan areas often fails to support normal succession to woodland vegetation, for reasons that are not known. Restoration of diverse communities of native woody plants on such sites is important because of the need to increase habitat for wildlife and plant biodiversity, create corridors and decrease distance between areas of natural habitat, support migratory birds, and provide opportunities for environmental education and recreation in densely populated urban areas. We propose to test methods that may stimulate woody plant colonization of closed landfills, an abundant type of derelict land, by planting small patches of woody plants that can rapidly colonized the site. We will experimentally determine the patch size site, and will test a series of hypotheses concerning the causes for the inhibition of natural succession. The study will be conducted on a recently closed landfill at Fresh Kills, NY. Patches of 7, 21, and 72 individuals of 7 species will be created in a randomized block design. Seed rain, recruitment and survival of seedlings, and herbivory will be monitored in the patches and on transects extending outward from each patch; these studies will test hypotheses that dispersal and herbivory limit natural woody plant establishment. Soil qualities, including organic matter, pools of N and P, N mineralization rae, root growth and mycorrhizal infection, will also be monitored within the patches and transects, and will test hypotheses concerning below- ground changes over time will permit testing of hypotheses concerning linkages among these processes. By evaluating hypotheses regarding both above- and below-ground processes, we will be able to compare their relative importance during succession. Subsequently, this project will result in design recommendations for restoration methods used on derelict land throughout the region.
