Urban forests, much like those of college campuses can be unbalanced in species diversity, and richness, which can lead to devastation. By determining these factors and applying a standard guide, the health of the forest is able to be established, and in doing so creating a better way to manage the trees. The standard guide used is the 10-20-30 rule, which says that no more than 10% of the trees should be of the same species, no more than 20% of the trees should be from the same genus, and no more than 30% should be from the same family. The 10-20-30 rule is often used as a standard to determine if the species diversity is acceptable, inadequate, or a possible cause for concern in the urban forest. Dickinson College currently has no reference to the standard of its urban forest. There is also concern of using non-native trees in the urban forest, and if that has a negative impact on the overall forest. The project was started in the spring of 2010 by Mark Scott and Jim Ciarrocca to document all of the trees on campus, so that Dickinson could become an arboretum. This project explores species diversity in eight different sections of campus, the overall richness of the campus trees, the location of the non-native trees, as well as designating location of water accumulation on the campus. Since the start of this project 814 trees have been tagged, and there are 132 unique tree species. Overall the species diversity of the campus is acceptable. There are no trees with greater than 6% of the same species, three are no trees with greater than 18% of the same genus, and there are no trees with greater than 18% of the same family, thus Dickinson’s campus is all within the 10-20-30 rule, and has acceptable species diversity.
This project specifically looked at ways to assist Mr. Scott in managing Dickinson College’s trees. The richness and species diversity were determined using the Marine Geospatial Ecology Toolset, created at Duke University. Using 3-meter elevation data from USGS, areas of depression were identified, where water would collect on Dickinson’s campus. This was done by filling in the depression using the fill tool, using the raster calculator the original elevation data was subtracted from the filled elevation data, this then gave the depression areas. This information will be used to assist Mr. Scott in making management decisions.