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.

项目组成员：卡米尔·亚当切夫斯基（Kamil Adamczewski）、乔尔·布鲁克（Joelle Brooker）、卡琳·约瑟菲（Karin Yosefi）、布里特尼·约里施（Brittney Jorisch）。本数据集的数据采集工作于约克大学（York University）附近的丹比林地（Danby Woodlot）开展，采集日期为2015年10月15日与2015年10月22日：其中10月15日的采集时段为当日15:00至16:30，10月22日的采集时段为当日15:09至15:55。10月15日天气为阴雨、多云且大风，气温11摄氏度；10月22日天气晴朗、少云且微风，气温13摄氏度。丹比林地因前期降雨略显泥泞，地面覆盖着周边树木飘落的落叶。本次野外实验共采集50株成年枫树样本（n=50），以测定其胸径（diameter breast height，单位：厘米）。本实验将株高不低于180厘米的枫树定义为成年个体。使用样带（transect）测定目标枫树的胸径后，以两条3米×3米的样带围绕位于样方中心的成年枫树，搭建出半个样方（half-sized quadrat），剩余半个样方通过目视估算完成。随后通过目视计数法统计该枫树周边的植物物种多度（abundance），统计范围不包含枫树本体。接下来，通过手指围成正方形样方，将其朝上指向天空，估算枫树冠层占据的空间比例，以此计算该枫树的冠层覆盖百分比。完成所有数据记录后，使用橙色胶带对该成年枫树进行标记，随后开展下一株枫树的实验。本实验旨在探究成年枫树的生长状况与周边植物物种多度、光照暴露程度之间的相关性，其中胸径被用作成年枫树生长状况的指示指标。