The Effect of Plant Abundance and Exposure to Light on the Growth of Adult Maple Trees

Group Members: Kamil Adamczewski, Joelle Brooker, Karin Yosefi, Brittney Jorisch. The data was collected at Danby Woodlot near York University on October 15, 2015 and October 22, 2015. Data was collected between 3:00pm and 4:30pm on October 15, and 3:09pm and 3:55pm on October 22. On October 15, the weather was rainy, cloudy, and very windy with a temperature of 11 degrees Celcius. On October 22, the weather was sunny, few clouds, and slightly windy with a temperature of 13 degrees Celcius. Danby's woodlot was slightly muddy from previous rain activity, and covered with leaves that fell from the surrounding trees. For this field experiment, fifty (n=50) adult Maple trees were sampled to determine their diameter breast height in centimetres. A Maple tree was considered to be an adult if it was as tall as or taller than 180 centimetres. After its diameter breast height was measured using a transect, a half-sized quadrat was formed by using two 3 metre by 3 metre transects, which surrounded the adult Maple tree which laid in the middle. The other half of the quadrat was visually estimated. Then, the abundance of plant species surrounding the Maple tree was collected by visually counting them, excluding the Maple tree itself. Then, by forming a square with one's fingers, the percent canopy cover of the Maple tree was calculated by pointing the square quadrat upwards and estimating the amount of space that the canopy of the Maple tree took up. After all this data was recorded, the adult Maple tree was tagged with orange tape, and the experiment continued to the next Maple tree. The purpose of this experiment was to find a correlation in Maple tree growth based off of the amount of plant species surrounding that Maple tree (abundance), as well as its exposure to light. Diameter breast height was used as an indicator for the growth of the adult Maple tree.