Density of Vegetation According to Light Abundance in Habitats

On October 19th and 26th from 3:30-5:30pm, a field experiment was conducted in the Danby Woods of York Uiversity. Weather conditions were sunny, few clouds, and slightly windy around 14-16 degrees Celsius. The grassland was a field with overgrown grass and plantlife and few tress. The woodland was densely populated with trees and mosty covered by leaves in the air space.<br>The purpose of this experiment was to find any correlation between light coverage or habitat and density of vegetation through the quadrat sampling technique.<br>An hypothesis set for this experiment is that the amount of sunlight able to reach a particular area would be due to lack of obstruction of the light coming in. With sunlight, the prediction is that the grasslands will have a larger density of vegetation due to minimum obstruction by trees as opposed to the woodlot.<br>The environment plays a factor in the density of vegetation due to an obstruction of large trees and thereby sunlight and nutrients for the smaller plant life to grow. The prediction here is that the woodlot will have a lower density of vegetation due to the amount of tall trees and canopy coverage. Otherwise, a null hypothesis would state that there is no difference between the abundance of vegetation in both habitats. This dataset shows the abundance of vegetation in each habitat within 100 quadrat trials.<br>The sampling process was done using the quadrat sampling technique and random number generating. A random number between 1-20 was chosen in order to count the number of steps to take and another generator between 1-4 used to determine the direction (1 = North, 2 = East, 3 = South, 4 = West) then a quadrat was placed at the distace chosen by the generator. Once the quadrat is placed, first the vegetation abundance was estimated as a percentage based on the vegetation within the quadrat and determining which was dead (bronlimp) or alive (green and upright). Those that are viable were counted as a percentage of abundance. Light abundance was calculated using a 1x1m blank piece of cardboard. The cardboard was placed inside the quadrat facing the sky with sunlight shown onto it. Where there was sunlight with no shadow, sunlight coverage was estimated into a percentage. This process was repeated 50 times for the grassland habitat and 50 times for the woodlot habitat on October 19, 2015 and repeated an additional 50 times for each habitat on October 26, 2015.<br>Lab performed with group members Felicia O., Richer L., Dylan C.,Brandon B., and Alex D. split into teams.

2015年10月19日与26日的每日15:30-17:30，研究团队于约克大学（York University）丹比林地（Danby Woods）开展野外实验。实验当日天气为晴，偶有薄云，风力微弱，气温约14-16摄氏度。其中草原生境为杂草丛生、植被繁茂且树木稀少的地块；林地生境则树木茂密，林间空间几乎完全被叶片覆盖。
本实验旨在通过样方采样法（quadrat sampling technique），探究光照覆盖度或生境类型与植被密度之间的相关性。
本实验提出的研究假设为：特定区域的光照入射量取决于光照是否存在遮挡物。据此预测，相较于林地生境，草原生境因树木遮挡更少，植被密度更高。此外，高大树木的遮挡会影响光照与养分供给，进而制约小型植物的生长，因此另一预测为林地生境的植被密度更低。反之，零假设（null hypothesis）则认为两种生境的植被丰度无显著差异。本数据集包含100次样方（quadrat）采样中两种生境的植被丰度数据。
采样过程采用样方采样法结合随机数生成法完成：首先生成1-20的随机数以确定行进步数，再生成1-4的随机数确定行进方向（1为北、2为东、3为南、4为西），随后在对应位置放置样方。样方放置完成后，先基于样方内的植被估算其丰度百分比，并区分枯死（呈bronlimp状态）或存活（呈绿色且直立状态），仅将存活植被的丰度以百分比计数。光照丰度则通过1×1米的空白纸板测算：将纸板置于样方内朝向天空，使阳光直射其上，将无阴影的受光区域按百分比估算光照覆盖度。本实验于2015年10月19日针对草原生境与林地生境各完成50次采样，并于2015年10月26日针对两种生境各追加50次采样。
本实验由Felicia O.、Richer L.、Dylan C.、Brandon B.以及Alex D.等小组成员分组合作完成。