The relationship between closely paired trees and their condition with respect to tree diameter at breast height

Metadata: Tree # - The number of trees that were sampled in the woodlot at York University. Total of 20 trees. Distance to Next Tree - The distance between closely paired trees in centimetres using a transect measuring tape. Distance between tree 1 to tree 2 and so on. DBH - The diameter at breast height of a tree in the woodlot measured in centimetres using a transect tape from the floor to the chest of the experimenter.Condition - A measurement of how alive a tree appears according to a derived system where 0 = dead, 1 = living, and 2 = huge green canopy Site description: Data collected on September 21, 2016 at 4:30 p.m in the Danby Woodlot on York university campus on a sunny afternoon with an approximate temperature of 26 degrees Celsius. The surroundings contained a variety of different tree species as well as other vegetation in a natural setting. Other experiments were ongoing in the same location. Methods: The tree data was collected at the Danby woodlot on the York University campus. Adult trees, that were minimum twice a person's height, were randomly sampled by the experimenters during a three hour period on a sunny afternoon. The distance in centimetres using transect measuring tapes was measured between one tree to the next closest tree. The diameter at breast height of the tree was also measured for all trees. Finally, the conditions of all trees were taken into account when sampling 10 pairs for a total of 20 trees. Hypothesis: The distance between closely paired trees and the associated diameter at breast height of those trees is indicative of the tree condition because competition for nutrients between closer trees can result in different amounts of growth. Also, diameter increment is a common feature in measuring tree growth. The condition of the tree will be a reflection of the diameter and available nutrients. Predictions: 1)Trees that are closer together in distance will not be equally healthy 2)The larger the diameter of the tree then the greater the health condition of the tree.

元数据：
树木编号（Tree #）：用于标识约克大学林地内的采样树木，本次共完成20株树木的采样。
相邻树木间距（Distance to Next Tree）：采用样带卷尺测量的成对紧密相邻树木间的距离，单位为厘米，即树木1与树木2、后续树木依次类推的间距。
胸径（DBH）：林地内树木的胸高直径，测量方式为从地面至实验者胸部高度处，使用样带卷尺测得，单位为厘米。
树木健康状况（Condition）：基于衍生评估体系的树木存活状态量化指标，其中0代表枯亡，1代表存活，2代表拥有茂密绿色冠层的健壮大树。

样地概况：数据采集于2016年9月21日下午4时30分，地点为约克大学校园内的丹比林地（Danby Woodlot），当日为晴朗午后，环境温度约26摄氏度。样地内包含多种乔木树种及其他原生植被，同期该区域还开展了其他实验项目。

实验方法：本次树木数据采集于约克大学校园丹比林地。实验人员于一个晴朗午后的三小时时段内，随机采样了高度至少为成人两倍的成年树木。使用样带卷尺测量每株树木与其最近邻树之间的间距（单位：厘米），同时测量所有采样树木的胸径，并记录每株树木的健康状况。本次共采集10组树对，总计20株树木。

研究假设：紧密相邻树木间的间距及其胸径可反映树木的健康状况，原因在于距离更近的树木间对养分的竞争会导致生长量存在差异。此外，胸径增量是衡量树木生长的常用指标，树木健康状况可反映其胸径及可获取养分的情况。

研究预测：1）间距较近的树木，其健康状态并不一致；2）树木胸径越大，则其健康状况越好。