地衣是如何通过破壁来发射其孢子的: 研究人员报告说，当Sphagnum 地衣孢子从其被囊中破壁而出的时候，拜一种极小的蘑菇云之赐，它们可在空气中到达超过10厘米的范围之中，这种蘑菇云可帮助将这些孢子向上驱动。 这种相同种类的螺旋状结构还可帮助水母和鱿鱼在水中推进。但是这些所谓的“涡环”在此之前却一般没有与植物类发生联系。 Sphagnum 地衣所形成的厚实的簇丛覆盖了地球陆地表面的约1%，它对地球的碳循环非常重要，因为它比其它种类的植物可储藏更多的碳。 为了繁衍，这些与大地相拥的地衣必须将其孢子投射到足够的高度，这样它们才能被风力携带至远距离的地方。 在一篇Brevium中，Dwight Whitaker 和 Joan Edwards证明，这些孢子所到达的高度无法简单地用它们破壁而出的力量来解释。 通过捕捉到的孢子破壁投射的高速视频，研究人员确认，狂暴的涡环为这些孢子提供了额外的助力，并将其携带至足够的高度而被空气的湍流播散。 一则相关的专家意见书对这一研究进行了讨论。
Article #6: "Sphagnum Moss Disperses Spores with Vortex Rings," by D.L. Whitaker at Pomona College in Claremont, CA; J. Edwards at Williams College in Williamstown, MA.
联系人: Joan Edwards，+1-413-281-7351 (手机) 及 +1-413-597-2472 (办公室电话) 或 joan.edwards@williams.edu (电子邮件)。Dwight L. Whitaker，+1-909-607-9795 (办公室电话) 或 +1-909-451-3221 (手机), 或 dwight.whitaker@pomona.edu (电子邮件)。
Article #5: "The Aerodynamic Gun of Sphagnum Mosses," by J.L. van Leeuwen at Wageningen University in Wageningen, Netherlands.
Science 23 July 2010:
Vol. 329. no. 5990, p. 406
DOI: 10.1126/science.1190179
Sphagnum Moss Disperses Spores with Vortex Rings
Dwight L. Whitaker1 and Joan Edwards2
Sphagnum spores, which have low terminal velocities, are carried by turbulent wind currents to establish colonies many kilometers away. However, spores that are easily kept aloft are also rapidly decelerated in still air; thus, dispersal range depends strongly on release height. Vascular plants grow tall to lift spores into sufficient wind currents for dispersal, but nonvascular plants such as Sphagnum cannot grow sufficiently high. High-speed videos show that exploding capsules of Sphagnum generate vortex rings to efficiently carry spores high enough to be dispersed by turbulent air currents. Spores launched ballistically at similar speeds through still air would travel a few millimeters and not easily reach turbulent air. Vortex rings are used by animals; here, we report vortex rings generated by plants.
