Quercus bicolor, quercus palustris, acer saccharum, salix nigra and platanus occidentalis are predominantly in the upper watershed. Comparison of Basal Areas. Non-North American exotic trees are concentrated in the lower watershed. The others have very discrete distributions but are abundant where they occur. The watershed is characterized by a geologic, soils and hydrologic gradient, ranging from schist that weathers into a well-drained soil in the upper watershed to saprolitic soils weathered primarily from gneiss in the lower section.
Flooding is much less frequent in the lower watershed, where streams are more deeply incised.
Superimposed on this gradient is a history of human activity that has altered local riparian habitats. Some of the vegetation distributions can be explained by specific human alterations of the natural gradients. This project has two primary goals. The second is to identify key social and economic forces driving ecological change at this time. The period selected is critical because it was during this time that a professional forestry agency was established in Maryland.