Ecosystem history helps not only to establish realistic and sustainable restoration and conservation goals, but also to elucidate the complex of driving forces that have led to the current state of a site. A conceptual model of the driving forces provides input to determine the best approach to take for restoration and management. Using a variety of historical methods, including palynology, documentary analysis and field studies, we will illustrate how this approach can lead to novel and unexpected interpretations and hence management decisions in two kinds of wetlands in New Jersey, a remnant glacial lake and a coastal plain seepage fen.
Results/Conclusions
The Great Swamp, much of which is now a National Wildlife Refuge, lies in a glacial lake basin in northern NJ. The surficial geology forms a distinct pattern, with a major east/west orientation. Superimposed on this pattern is a centuries-long history of human-caused disturbance. The patterns of resource use have depended on the hydrology, soils and surficial geology This has produced a landscape structured by the complex interaction of interdependent drivers, acting over multiple temporal and spatial scales. A conceptual model of these drivers allows an evaluation of their relative importance in determining current plant communities, which helps inform restoration and management at the NWR. The NJ Pine Barrens landscape includes an extensive network of groundwater-influenced streams and swamps surrounded by xeric pitch pine- and oak-dominated uplands. Within the riparian wetland systems there are open, acidic seepage fens that support an extraordinary diversity of plants, many of which are very rare in NJ and globally imperiled. Basal peat dates indicate that most of these originated 8000-9000 BP. Over the last 300 years, many have been disturbed by mining peat or bog iron, logging of Atlantic white cedar, and/or construction of cranberry bogs. Other disturbance factors include fires, altered hydrology, water pollution and trampling. Studies of the geomorphology, paleoecology and vegetation ecology of several sites has allowed the NJ DEP to determine that these fens are well-established natural systems with restricted geographic distribution, and thus are globally very rare, serving as excellent reference ecosystems. Differences in site history and current vegetation community structure provide evidence of driving forces that influence succession/stability, providing important guidance for restoration, management and protection of these rare wetlands.
