The effects of crowdedness and shadiness on plant height of Solidago canadensis, Cirsium vulgare, and Aster prenanthoides

Methods: Two transects were laid down in the grasslands east of Stong Pond on two separate days. On Tuesday, October 14, 2014 samples were taken from the inner region of the grassland (I) and on Tuesday, October 21, 2014 samples were taken from the outer region of that same grassland (O). Every 5 metres along the transect, the heights of the nearest Solidago canadensis, Cirsium vulgare, and Aster prenanthoides found within 1m from the transect were measured from where the stem touched the ground to the highest point on the plant. Each plant’s level of shadiness and crowdedness around the plant was recorded. This was repeated for a total of 60 replicates (30 for each transect). This data was then used in ANOVA tests and Tukey post-hoc tests to analyze shadiness versus the average plant height of each different species. Next, correlation tests were used to analyze crowdedness versus plant height of each species. This experiment was done to test whether the amount of sunlight affects plant height and whether the amount of crowdedness affects plant height.

研究方法：于两个独立单日在斯通池塘（Stong Pond）东侧的草地布设两条样带。2014年10月14日（周二），采集该草地内部区域（标记为I）的样本；2014年10月21日（周二），采集同一草地外部区域（标记为O）的样本。沿每条样带每间隔5米，对样带周边1米范围内距离最近的加拿大一枝黄花（Solidago canadensis）、普通蓟（Cirsium vulgare）以及前胡叶紫菀（Aster prenanthoides）进行株高测量，测量起点为茎秆与地面接触处，终点为植株最高点。同时记录每株植物的遮阴程度及周边拥挤度。本实验共完成60组重复采样（每条样带30组）。随后采用方差分析（ANOVA）与Tukey事后检验，分析遮阴程度与各物种植株平均高度的关联；并通过相关性检验，分析拥挤度与各物种植株高度的相关性。本实验旨在验证光照量是否影响植株株高，以及植株周边拥挤度是否对株高产生影响。