Experimental design: field experiment

The experiment was conducted in a woodlot located at the Keele campus of York University in Toronto, Ontario. It was conducted on the 15th and 22nd of October 2014 between 2:45pm and 4:30pm and the weather was cloudy with light precipitation. The only equipment required for the complete execution of the experiment was two 25m transect tapes and the chosen tree sample was a sugar maple tree (Acer Saccharum).First randomly place the 25m transect measuring tape from the edge of the woodlot (defined as the first tree you encounter as you enter the woodlot) to the centre, then at every instance we encounter an adult tree (defined as a tree twice the height of the students conducting the experiment) along the transect tape on both sides, various measurements were taken. First the distance on the transect tape where each sample maple tree was found was recorded then the dbh of the sample maple tree was also obtained using the second 25m transect tape. The distances from the maple tree to the three closest adult trees were obtained and recorded then the arithmetic mean of those distances was used to estimate the density of that specific maple tree. This was repeated for a total sample size of 30 transects.

本实验于加拿大安大略省多伦多市约克大学基尔校区的一片小片林地中开展，实验时段为2014年10月15日与22日的14:45至16:30，当日天气为多云伴轻微降水。完成本实验所需的唯一器材为两盘25米长的样带卷尺（transect tape），实验选取的样本树种为糖枫（Acer Saccharum）。具体流程如下：首先从林地边缘（定义为进入林地时遇见的第一棵树）向林内中心随机布设25米长的样带卷尺；随后沿样带两侧每遇到一棵成年树木（定义为身高为实验学生两倍的树木）时，即开展多项测量：首先记录每棵样本糖枫在样带卷尺上的对应距离，此外还使用第二盘25米样带卷尺测量该样本糖枫的胸径（DBH）；之后测量并记录该糖枫树到最近的三棵成年树木的距离，以这些距离的算术平均值估算该样本糖枫树的种群密度。本实验共重复上述流程，最终完成30条样带的采样。