Effects of density and sunlight on diameter of silver maple trees

Hypothesis The diameter at breast height (dbh) of a tree will be larger when there is a low density of trees surrounding it. This allows for more sunlight to reach that specific tree and outgrow the others for dbh. Predictions As density increases, the dbh of the sampled tree will decrease.As sunlight increases, the dbh of the sampled tree will increase.As density decreases and sunlight increases, the tree will have the highest possible dbh. Methods For this experiment, the targets were adult silver maple trees located in the woodlot at York University. This experiment aimed to measure the effects of density and sunlight on the diameter at breast height (dbh) of the sampled trees. The trees were selected randomly by walking 10 steps north and 5 steps east into the woodlot and the closest adult maple tree was chosen. An adult tree was classified as a height above 3 meters for this experiment. The dbh was measured in centimeters with a transect tape. A radius of 10 meters was measured from the sampled tree and all of the surrounding adult trees were counted within this radius. The sunlight coverage was measured with a 10 cm by 15 cm frame positioned towards the sky and canopy of the tree from its base. Sunlight was recorded as the percent of sky seen through the canopy of the tree. A distance of 5 meters from the edge of the previously sampled tree was walked along a transect and 10 steps north plus 5 steps east were taken to select the next closest maple tree. A total 35 adult maple trees were surveyed.