Observations of forest area on East end of York University Keele campus

At York University, Keele campus, on Friday, September 26, 2014, a study site was located near a parking lot on the eastern end of the campus. The study site had a grassland area and a forested area which bordered each other. There was minimal cloud coverage and the temperature during the study was reasonably warm (23 degrees Celcius). Within the forested area, the distribution of adult trees and their saplings were observed and their diameter at breast height was observed in relation to their canopy size. This was done by first identifying the forest edge as the place where the grassland stopped and the first adult tree observed along the forest edge was use as the starting tree. Using the first adult tree (dbh ≥ 20 cm) to mark the forest edge, a group of 3 (Cait Carew, Lilach Halevi, and Nitharsija Srikanthan) took a measurement from the base of that tree to the base of the nearest adult tree using a transect measuring tape. At this tree, the tape measure was wrapped around the tree at breast height (around 1.3 m above ground) in order to measure the tree diameter. Trees were not considered adults if their diameter at breast height was less than 20cm. The trees were ranked on a scale of 0-2 to identify them as being dead (0), alive (1), and having a dense canopy (2). The distance between the first adult tree to the next closest tree was measured using the transect measuring tape along the forest floor from the base of one tree to the base of the other. The above process was repeated until 20 trees were sampled in this way. Beech (Fagus) trees were chosen as the tree type of interest for the next study. It was identified by its leaves which are characteristically serrated around the edges and are shaped similar to teardrops. Starting from the edge of the forest, sampling started with the first visible adult Fagus. The diameter at breast height was recorded at this tree, and the canopy density was recorded. The canopy was observed by creating a square shape with fingers and orienting them up toward the sky. The relative canopy coverage was estimated by observing the amount of leaf coverage within the square shape. From the base of the adult Fagus, the nearest sapling was identified by observing the forest floor around the base of the tree. Some saplings were very close to the base of the tree, however, as the diameter at breast height of the sapling was required, saplings below breast height were not considered. The distance between the base of the adult tree and the base of the nearest sapling (with a height that reached a minimum of breast height) was measured using a tape measure. The diameter of the sapling was measured at breast height in the same way as the adult trees. The above process was repeated until 10 adult and sapling pairs were sampled.

2014年9月26日周五，在约克大学（York University）基尔校区（Keele campus），研究样地设于校区东端一处停车场附近。该样地包含一片草地与一片毗邻的林地。当日云量极少，研究期间气温适宜，为23摄氏度。在林地内，研究人员观测了成年树木及其幼树的分布情况，并分析了其直径在胸高位置（diameter at breast height, DBH）与冠幅的相关性。研究首先以林草交界线作为森林边界，将沿该边界发现的第一株成年树木作为起始样树。由3名研究者（凯特·凯尔（Cait Carew）、莱拉赫·哈勒维（Lilach Halevi）、尼塔萨贾·斯里坎坦（Nitharsija Srikanthan））使用样带卷尺（transect measuring tape）从该起始树的基部量至最近的另一株成年树基部。在该株树木处，将卷尺绕于胸高位置（距地面约1.3米处）以测量其胸径。胸径不足20厘米的树木不视为成年树。研究人员将树木按0-2级进行分级：0代表枯树，1代表活树，2代表冠层茂密的树木。使用样带卷尺沿林地表层测量从起始成年树基部至下一株最近树木基部的距离。重复上述流程，直至采集到20株样树样本。本次研究选取山毛榉属（Fagus）树木作为目标树种，其叶片边缘具典型锯齿状，外形近似水滴状，可据此识别。从森林边缘开始，以第一株可见的成年山毛榉作为起始样树，记录其胸径与冠层密度。冠层密度通过双手围成正方形并指向天空进行观测：通过统计正方形范围内的叶片覆盖量估算相对冠层覆盖率。以该成年山毛榉的基部为起点，在其周边林地表层寻找最近的幼树。需注意，幼树需达到胸高以上方可纳入统计（因需测量其胸径），即胸高以下的幼树不予考虑。使用卷尺测量成年树基部至最近幼树基部的距离，幼树胸径的测量方法与成年树一致。重复上述流程，直至采集到10组成年-幼树样本对。