Rick Van de Poll
Department of Environmental Studies
The purpose of this investigation was to inventory the tree, shrub, sapling/seedling and herbaceous strata within three observed community types (Maple-Birch-Laurel, Pine-Oak, Red Maple) that exist on 15.7 hectares (38.8 acres)) of the Princeton nature Trail property and to determine how the three community types differ in plant composition. Systematic sampling plots were utilized within the three cover types and herbaceous strata, seedlings, shrubs, saplings and trees were inventoried utilizing nested circular plots. During the summer of 1999, the inventory documented 70 species of herbs, 12 species of tree seedlings, 22 species of shrubs, 14 species of saplings, and 12 species of trees. The data was analyzed using DECORANA (detrended correspondence analysis) and TWINSPAN (two-way indicator species analysis) to determine how the three forest communities differ and how much in stand diversity was present. At the tree level, the TWINSPAN analysis demonstrated that these were dominant species in the three communities. At the herbaceous level of analysis, the same community types were identified, however three sub-communities were isolated within the Red Maple Community: 1. Red Maple-Arrowwood-Cinnamon Fern, 2. Red Maple-Blueberry-Wintergreen and 3. Red Maple-Alder-Jewelweed. At the shrub level TWINSPAN also isolated the same three community types (Oak-Laurel, Pine-Blueberry, and Red Maple). The Red Maple Community was divided into two sub-communities that have been named: Red Maple-Arrowwood and Red Maple-Alder-Sub Communities. The DECORANA output for the herbaceous and shrub strata clearly define a wet to dry gradient as follows, Red Maple Communities, Oak-Laurel Community to Pine-Blueberry Community. The DECORANA results for trees weakly suggest a wet to dry gradient. Utilizing these data, along with Mass GIS data, a map was created that reflects topography, dominant and sub-community plant types, sampling plots, the Princeton Nature Trail and streams.