Exhaustive map locations of tupelo trees sampled in bottomland forests

Shea et al (1993) studied the small-scale spatial patterning of water tupelo, a gynodioecious tree. Locations of all trees in 50m x 50m quadrats were mapped using compass and tape. By inspection of flowers in spring, each tupelo was classified as male, female, or juvenile (not flowering). The biological questions concern spatial segregation. Do males tend to occur in the vicinity of other males. Do females tend to occur in the vicinity of other females? The data are records of all water tupelo trees in 3 approx. 50 m x 50m plots in bottomland hardwood forests. They are formatted as plot, sex (F = 1, M = 2, or juvenile = 3), index number of nearest neighbor (If a tree 1 in a plot has a value of 185 for nearest neighbor, tree 185 is its nearest neighbor), x and y (the spatial location in meters).

Shea等人（1993）针对具雌全异株（gynodioecious）习性的水紫树（water tupelo）的小尺度空间分布格局展开了研究。研究人员采用罗盘与卷尺，对50m×50m样方（quadrat）内所有树木的空间位置进行了测绘定位。通过春季观察花部特征，将每株水紫树划分为雄株、雌株或幼树（尚未开花）。本研究的核心科学问题聚焦于空间隔离现象：雄株是否倾向于聚集在其他雄株的周边？雌株是否倾向于聚集在其他雌株的周边？本数据集收录了3处低地硬木林（bottomland hardwood forests）中约50m×50m样方内的全部水紫树观测记录。数据字段依次为：样方编号、性别编码（雌株F=1，雄株M=2，幼树juvenile=3）、最近邻个体索引号（若某样方内第1号树的最近邻索引值为185，则代表第185号树为其最近邻个体）、以及x与y坐标（单位为米，代表该个体的空间位置）