Data on Eastern Black Walnut Trees at Saywell Woodlot

Data was collected at York University’s Saywell Woodlot for a total of 56 Eastern black walnut trees (scientific name: Julgans nigra) to determine whether or not distance to urbanization or age played a role in the canopy coverage of this species of trees. The study was conducted on two separate days, October 19th, 2015 at nearly 2:45pm when the temperature was 14 degrees Celsius with a sunny sky, and on October 26th, 2015, also at nearly 2:45pm with the temperature being 12 degrees Celsius and a sunny sky. On the first day, 33 trees were examined and on the second day, 23 trees were examined. The age of the tree was determined by measuring its diameter at breast height, 1.2m above the ground. If the tree had a diameter of 0.25m or greater, it was considered to be an adult and if it had a diameter less than 0.25m, it was considered to be a sapling. The distance of the tree to urbanization was determined using a line transect tape and measuring the distance of the tree to the closest road. If the distance was greater than 30m, the maximum distance the line transect tape could measure, one of the researchers would stand at the 30m mark while the other researcher measured from that position to the nearest road and added 30m to their obtained measurement. The canopy coverage of the tree was determined on a scale of 1 (no canopy coverage) to 5 (full canopy coverage), by holding a square up into the sky underneath the tree and determining how much of the sky was covered by the tree’s leaves, branches or fruits. Overall, the study was conducted successfully.