Acer saccharum crowding and forest position relationships to dbh

Observations were taken at the Danby Woods forest on the York University Keele campus. Two variables of Acer saccharum specimens (crowding and distance to forest edge) were studied in relation to their diameters at breast height to determine the possible affects of competition on tree size. Specimens were identified on the basis of leaf morphology. For the purposes of this investigation, trees were defined as individual, living trees at least double the height of the average investigator. The perimeter of the forest was defined as the outmost tree line, behind which no trees were located for at least 5 meters. 25-meter belt transects were placed starting from the perimeter and proceeding directly into the forest. Starting points for transects were pseudo-randomly selected by selecting four potential starting points at random and using a random number generator to determine which one would be used. Starting points progressed around the entirety of the forest's perimeter. All Acer saccharum specimens within 0.5 meters of the transect in any direction were studied. Crowding level was here determined by taking the mean of the distances of the three nearest trees to the specimen in question. Diameter at breast height was recorded using a separate 25m belt transect. Distances to forest edge were determined by the distance along the belt transect at which the specimen was located. All measurements were recorded to the nearest cm. In total 30 transects were taken over two separate trial dates within a time span of one week.