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）针对雌全异株（gynodioecious）树木水紫树（water tupelo）的小尺度空间分布格局开展了研究。研究人员借助罗盘与卷尺，对50m×50m样方（quadrat）内的所有树木空间位置进行了测绘。通过春季观察花朵特征，每株水紫树被划分为雄株、雌株或幼树（尚未开花）。本次研究的核心生物学问题聚焦于空间隔离现象：雄株是否更倾向于聚集在其他雄株周边？雌株是否更倾向于聚集在其他雌株周边？本数据集包含3处约50m×50m低地硬木林（bottomland hardwood forests）样地内的全部水紫树记录，数据字段依次为：样地编号、性别（雌株=1，雄株=2，幼树=3）、最近邻个体索引号（若某样地内第1号树的最近邻索引号为185，则第185号树即为其最近邻个体）、x与y坐标（单位为米，代表树木的空间位置）。