Determining the viability response of pine pollen to atmospheric conditions during long-distance dispersal
Determining the viability response of pine pollen to atmospheric conditions during long-distance dispersal
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DOI：
10.1890/07-2088.1
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发表时间：
2009-04-01
影响因子：
5
通讯作者：
Linden, Karl G.
中科院分区：
文献类型：
--
作者：
Bohrerova, Zuzana;Bohrer, Gil;Linden, Karl G.
森林树木的花粉可以在几十到数百公里的范围内移动，但它在这种长距离传播(LDD)中的生存能力的问题尚未得到回答。虽然对森林树种花粉活力的经验研究很少，但户外研究紫外线照射对花粉活力的贡献的可控和可扩展的数据是不可用的。一种允许量子的简单方案。本文描述了花粉活力对紫外线、温度和湿度的阳离子反应。在实验室尺度条件下，模拟包括不同湿度、温度和紫外线照射条件在内的各种大气条件来确定每个非生物胁迫因子的独立效应，并将经验函数用于将这些实验室尺度实验扩展到室外条件下。作为案例研究，在两年的时间里采集了两个火炬松种群的花粉，并用其来量化LDD期间大气条件对火炬松生活力的影响。与玉米花粉相反，火炬松的花粉活力因潮湿和寒冷条件而降低。花粉对UV-A和UV-B的活力响应在暴露一整天后活力下降了约10%。这些实验室发现得到了室外太阳照射实验的证实。福留在线辐射模型和探空仪观测数据集被用来估计LDD花粉可能遇到的典型条件。如果最初遇到强烈的上升气流，散布的火炬松花粉可能会被带到数千公里外的空中。火炬松花粉活力因非生物胁迫而降低的经验方程预测，在典型的外界条件下，50%的花粉将在LDD的24小时内存活。因此，花粉的存活范围比物理散布距离要短。我们实验中使用的方法适用于散布花粉活力的测定，特别是当需要区分不同不利条件的影响时。由我们的实验得到的经验生存方程可以用于大气扩散模型来估计树木花粉的生存范围。
Pollen of forest trees can move on the scales of tens to hundreds of kilometers, but the question of its viability during this long distance dispersal (LDD) has yet to be answered. While empirical studies of pollen viability in forest tree species are rare, controlled and scalable data to outdoor studies of the contribution of UV irradiation on pollen viability are not available.A simple protocol that allows the quanti. cation of the viability response of pollen to UV, temperature, and humidity is developed and described here. Bench-scale conditions that approximate a wide range of atmospheric conditions including different humidity, temperature, and UV irradiation condition are used to determine the independent effects of each abiotic stress factor, and empirical functions are fitted and used to scale these bench-scale experiments to outdoor conditions.As a case study, pollen was sampled from two populations of Pinus taeda during two years and was used to quantify the decrease in viability due to atmospheric conditions during LDD. Contrary to maize pollen, P. taeda pollen viability decreased due to humid and cold conditions. The viability response of pollen to UV-A and UV-B corresponded to a viability reduction of about 10% after a full day of exposure. These laboratory findings were corroborated by an outdoor solar exposure experiment.The Fu-Liou online radiation model and a data set of radiosonde observations were used to estimate the typical conditions that would be encountered by LDD pollen. If initially caught in a strong updraft, dispersing P. taeda pollen could be carried many days and thousands of kilometers in the air. The empirical equations for P. taeda pollen viability reduction due to abiotic stresses predicted that 50% of the pollen would survive 24 hours of LDD under typical external conditions. The viable range of the pollen is, therefore, shorter than the physical dispersal distance.The methods used in our experiments are applicable for determination of dispersing pollen viability, especially when effects of different adverse conditions need to be separated. The empirical viability equations that resulted from our experiments can be used in an atmospheric dispersal model to estimate the viable range of tree pollen.