Seed release by invasive thistles: the impact of plant and environmental factors
Seed release by invasive thistles: the impact of plant and environmental factors
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DOI：
10.1098/rspb.2007.0190
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发表时间：
2007-10-07
影响因子：
4.7
通讯作者：
Auhl, Richard
中科院分区：
文献类型：
--
作者：
Jongejans, Eelke;Pedatella, Nicholas M.;Auhl, Richard
扩散是空间动力学生物学研究中的一个关键过程，但扩散的启动往往被忽视，尽管有强烈的迹象表明，不同的扩散时间可以显着影响扩散距离。为了调查哪些植物和环境因素决定释放羽毛种子入侵蓟飞廉acanthoides和飞廉nutans，我们暴露了192个花头的每一个物种增加风速在全因子风洞实验与四个气流湍流，三个花头湿度和两个花头温度水平。种子释放的数量是最高的干燥和动荡的条件下，从头部已经失去了相当数量的种子，但不受花头大小，头部角度或温度。对试验录像的观察表明，在层流中需要更高的风速才能达到种子释放阈值，而对于C。被打湿了很长时间的棘状头。物种差异很小，虽然种子释放更敏感，以较低水平的动荡在更大的头和更开放的C。nutans头。了解种子释放偏向有利于远距离传播的天气条件，可以提高我们对入侵者传播的了解，并使管理者能够通过在关键时刻应用遏制策略来提高遏制策略的效率。
Dispersal is a key process in biological studies of spatial dynamics, but the initiation of dispersal has often been neglected, despite strong indications that differential timing of dispersal can significantly affect dispersal distances. To investigate which plant and environmental factors determine the release of plumed seeds by the invasive thistles Carduus acanthoides and Carduus nutans, we exposed 192 flower heads of each species to increasing wind speeds in a full-factorial wind tunnel experiment with four air flow turbulence, three flower head wetness and two flower head temperature levels. The number of seed releases was highest under dry and turbulent conditions and from heads that had already lost a considerable number of seeds, but was not affected by flower head size, head angle or temperature. Inspection of the trials on video showed that higher wind speeds were needed to meet the seed release threshold in laminar flows and for C. acanthoides heads that had been wet for a longer time. Species differences were minimal, although seed release was more sensitive to lower levels of turbulence in the larger-headed and more open C. nutans heads. Knowledge of seed release biases towards weather conditions favourable for long-distance dispersal improves our understanding of the spread of invaders and allows managers to increase the efficiency of their containment strategies by applying them at crucial times.