The Diversity and Abundance of Insect Species in a Grassland, and a Woodlot

Group Members: Loyal Tran, Anisa Amin, James Quach, Iiman Darman The group was split into two to save time; dataset 1 was collected with Loyal Tran. This data was collected at the Danby woodlot, and the grassland next to it on September 30, 2015 from 15:15 to 16:10. A 1m x 1m quadrat was used to collect 20 random samples, 10 from the grassland, and the other 10 from the woodlot. It was a sunny day with a few clouds in the sky. The weather was 16 degrees Celsius with a cool breeze. The ground was cool and damp as it was raining the day before. Insect abundance and number of RTU's was determined in each sample. Insect abundance is defined as the total number of insects in a quadrat and was determined by counting the total number of insects seen within 1 minute of observation. Each sample was observed for 1 minute. The environment in the quadrat was disturbed (i.e. moving plants, scattering the soil, etc.) as to see the insects that may have been hidden in the soil or by the surrounding vegetation. This allowed for us to observe many more individuals and RTU's. Number of RTU's is an estimate of the number of species and is defined as the number of different recognizable taxonomic units. This was determined by counting individuals with different physical characteristics. Any individuals that had major differences in physical characteristics were counted thought of as 2 RTU's. This data may be prone to error as visual observation is imprecise. Insects may have been camouflaged, too small, or hidden under surrounding vegetation or the soil. All of these characteristics may have affected the precision of this data.

项目组成员：Loyal Tran、Anisa Amin、James Quach、Iiman Darman。为提升工作效率，小组分为两组开展采样；数据集1由Loyal Tran负责采集。该批数据于2015年9月30日15:15至16:10，在丹比林地(Danby woodlot)及其毗邻的草地完成采集。本次采样采用1m×1m样方(quadrat)，共获取20份随机样本，其中10份采自草地，剩余10份采自林地。当日天气晴好，偶有薄云遮蔽，气温16摄氏度，伴有微凉阵风；受前一日降雨影响，地表阴冷潮湿。本次观测记录了每份样本的昆虫丰度与可识别分类单元(recognizable taxonomic units，RTU)数量：昆虫丰度定义为单一样方内的昆虫总个体数，通过1分钟观察期内计数所见昆虫总数确定，每份样本的观察时长均为1分钟。为暴露藏匿于土壤或周边植被中的昆虫，采样人员会对样方内环境进行扰动（如翻动植株、拨散土壤等），此举可提升观测到的昆虫个体与RTU数量。可识别分类单元(RTU)是物种丰富度的估算指标，其定义为具有差异化形态特征的昆虫类群总数，通过统计外观存在显著差异的个体数确定，凡形态特征存在明显差异的个体即被划分为对应数量的RTU。本数据集存在一定误差风险：视觉观测本身精度有限，昆虫可能存在伪装、体型过小，或藏匿于植被与土壤中，上述因素均可能影响数据采集精度。