Intraspecific variation in seed dispersal of a Neotropical tree and its relationship to fruit and tree traits

The distribution of wind-dispersed seeds around a parent tree depends on diaspore and tree traits, as well as wind conditions and surrounding vegetation. This study of a neotropical canopy tree, Platypodium elegans, explored the extent to which parental variation in diaspore and tree traits explained (1) rate of diaspore descent in still air, (2) distributions of diaspores dispersed from a 40-m tower in the forest, and (3) natural diaspore distributions around the parent tree. The geometric mean rate of descent in still air among 20 parents was highly correlated with geometric mean wing loading1/2 (r = 0.84). However, diaspore traits and rate of descent predicted less variation in dispersal distance from the tower, although descent rate−1 consistently correlated with dispersal distance. Measured seed shadows, particularly their distribution edges, differed significantly among six parents (DBH range 62–181 cm) and were best fit by six separate anisotropic dispersal kernels and surveyed f...

母树周围风播种子的分布格局，取决于传播体（diaspore）与植株性状、风速条件以及周边植被状况。本研究以新热带冠层树种优雅扁荚树（Platypodium elegans）为研究对象，探讨了母株传播体与植株性状的变异对以下三项指标的解释程度：(1) 静止空气中传播体的下落速率；(2) 森林内40米高观测塔所散播的传播体分布格局；(3) 母树周边自然状态下的传播体分布格局。20株母株的静止空气下落速率几何均值，与几何平均翼负荷（wing loading）的平方根呈极强相关性（r=0.84）。然而，传播体性状与下落速率对观测塔散播距离的变异解释度较低，尽管下落速率的倒数始终与散播距离呈显著相关。实测得到的种子阴影（seed shadow），尤其是其分布边界，在6株母株（胸径DBH范围62~181厘米）间存在显著差异，且分别以6个独立的各向异性扩散核（anisotropic dispersal kernel）及调查得到的[...]（原文未完整呈现）实现了最优拟合。