Mechanisms of long-distance dispersal of seeds by wind
Mechanisms of long-distance dispersal of seeds by wind
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DOI：
10.1038/nature00844
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发表时间：
2002-07-25
期刊：
影响因子：
64.8
通讯作者：
Levin, SA
中科院分区：
文献类型：
--
作者：
Nathan, R;Katul, GG;Levin, SA
长距离扩散（LDD）是气候变化后物种扩张、受干扰地区重新定居和害虫控制的核心（1-8）。目前的范例是LDD事件的频率和空间范围非常难以预测（9-12）。在这里，我们表明，耦合种子释放和空气动力学与湍流输送过程的机械模型提供了准确的概率描述的LDD的种子风。该模型可靠地预测了分散的种子的垂直分布的五个树种观察沿着一个45米高的塔在美国东部的落叶林。模拟结果表明，森林冠层以上的隆升是LDD的必要和充分条件，因此，他们提供了定量而不是任意定义LDD的手段。因此，种子上升的概率设定了长距离殖民化概率的上限。隆起的白杨种子平均比森林地面上的种子轻，但也包括最重的种子。由于上升的概率是可观的（高达15%），树木种子作物通常是巨大的，一些LDD事件将建立个人，可以严重影响植物动态大规模。
Long-distance dispersal (LDD) is central to species expansion following climate change, re-colonization of disturbed areas and control of pests(1-8). The current paradigm is that the frequency and spatial extent of LDD events are extremely difficult to predict(9-12). Here we show that mechanistic models coupling seed release and aerodynamics with turbulent transport processes provide accurate probabilistic descriptions of LDD of seeds by wind. The proposed model reliably predicts the vertical distribution of dispersed seeds of five tree species observed along a 45-m high tower in an eastern US deciduous forest. Simulations show that uplifting above the forest canopy is necessary and sufficient for LDD, hence, they provide the means to define LDD quantitatively rather than arbitrarily. Seed uplifting probability thus sets an upper bound on the probability of long-distance colonization. Uplifted yellow poplar seeds are on average lighter than seeds at the forest floor, but also include the heaviest seeds. Because uplifting probabilities are appreciable (as much as 15%), and tree seed crops are commonly massive, some LDD events will establish individuals that can critically affect plant dynamics on large scales.