Abscission of seeds and pollen

种子和花粉通过风传播的模型由于我们几乎完全缺乏关于事件的开始：脱落的知识而受到阻碍。在这里，我将测试以下假设：(1)在下午早些时候（风速和大气不稳定性最大，而相对湿度最小）存在强烈的分离倾向；(2)热带和中纬度地区所有植物对风和相对湿度的脱落响应相似；(3)对上升气流的偏好大于对下降气流的偏好；(4)脱落概率与阻力成正比（因此与风速的平方成正比）；(5)散布几乎完全是靠近海岸的内陆（由于正午的海风）和山上的上坡（由于正午的回流风）。

Models of seed and pollen dispersal by wind are handicapped by our almost complete lack of knowledge regarding the start of the event: abscission. Here I will test the hypotheses that (1) there is a strong bias toward abscission during the early afternoon (when wind speeds and atmosperic instability are maximized while relative humidity is minimized); (2) the abscission response to wind and relative humidity is similar for all plant species in both the tropics and mid-latitudes; (3) there is also a bias toward updrafts rather than downdrafts; (4) the probability of abscission is proportional to the drag force (and thus to the square of the wind speed); and (5) dispersal is almost entirely inland near coasts (due to the mid-day sea breeze) and upslope in the mountains (due to the mid-day anabatic winds).