The Comparison of R.cathartica and Acer at Danby

The data was collected on October 14th, and October 21st, 2015 at Danby’s Woodlot located at York University Keele Campus. At the beginning of the data collection, a member from the group noted down the time, weather conditions, and other information about the woodlot then proceeded towards data collection. To begin with, a 100m transect using the tape measures was set up from a randomly chosen edge to the middle of the woodlot. The samples were taken at every 5m starting from 0m that were labelled as station in a consecutive order. At each station sample 1, 2, 3 were taken on the right side of transect by Reena and Olivia. On the other side, sample 4 to 6 were taken by Fara, Huda, and Ratiba. To obtain the samples, a 2mX2m quadrat was set up using the tape measures; in which , the following was collected. First, the abundance of native seedlings in the quadrat was determined by counting the number of native seedlings present in the quadrat. The native plant that was incorporated for the native tree seedling sample was Acer. Since, it was observed as the dominant native species in the woodlot. Moreover, the seedlings of 50-120cm, and with orange, green, red and yellow maple leaves were visually determined and counted. Secondly, the abundance of R.cathartica shrub was determined. In the quadrat to do this large trees with black berried along with smaller plants about the same size as the Acer seedlings were incorporated. These R.cathartica was visually identified based on the leaf shape, and the presence of black berries on the large trees. In addition, the unchanged colour green made the invader more distinguishable. Third, percentage of light in each quadrat was measured by standing at a random point in the quadrat. The extent of canopy coverage was determined to see how much light is reaching the ground. A square is made using the fingers of the observer and held up. The percentage of the square not covered by the trees is the percentage of light reaching the ground. This information was collected for each variable.

本数据集采集于2015年10月14日及21日，采集地点为约克大学基尔校区（York University Keele Campus）的丹比林地（Danby’s Woodlot）。数据采集启动之初，团队一名成员先记录了采集时间、天气状况及该林地的相关基础信息，随后正式开展数据采集工作。首先，使用卷尺沿随机选定的林地边缘向林内布设一条长100米的样带（transect），以0米处为起点，每隔5米设置一个采样点（station）并按连续顺序编号。Reena与Olivia负责在样带右侧采集样本1至3，Fara、Huda及Ratiba则在样带另一侧采集样本4至6。采样环节中，使用卷尺搭建规格为2m×2m的样方（quadrat），并完成以下三类数据的采集：其一，统计样方内本土幼苗的丰度：对样方内出现的本土幼苗数量进行计数，本次采样选取枫属（Acer）植物作为本土乔木幼苗的代表类群，经观察该物种为该林地的优势本土物种；同时需视觉识别并计数株高介于50-120cm、叶片呈橙、绿、红、黄色的幼苗。其二，统计鼠李属（R.cathartica）灌木的丰度：在样方中选取结黑色浆果的大型植株及尺寸与枫属幼苗相近的小型植株作为统计对象，该入侵物种可通过叶片形态、大型植株上的黑色浆果进行视觉识别，且其保持不变的绿色也使其更易被区分。其三，测量每个样方的光照百分比：在样方内随机一点站位，观察者用手指围成正方形举至眼前，统计该正方形未被树冠覆盖的比例，以此代表到达地面的光照百分比。上述各项变量的相关采集信息均已完成记录。