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Aerodynamics of Ephedra trifurca

II. Computer modelling of pollination efficiencies

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Computer simulations are used to predict the behavior of pollen grains with different physical properties within the acceleration field created around the ovules of the gymnosperm Ephedra trifurca. A modelling procedure is given that (1) calculates the number of pollen grains captured by an ovule's pollination-droplet and (2) gives a correlation between pollination efficiency and the physical properties (= mass, size) of different types of pollen. Based on this procedure, the number of Ephedra pollen grains captured by micropyles can be less than the number captured from other species. However, the mass and size of Ephedra pollen grains appear to coincide with those predicted to yield a local maximum of pollination efficiency, i.e. slightly larger or smaller values of either mass or size would decrease the probability of capture. In addition, the properties of Ephedra pollen grains operate synergistically in the aerodynamic environment around ovules and are focused to collide with pollination-droplets. By analogy, the properties of Ephedra pollen coincide with those predicted for a localized “adaptive peak”. The physical properties of pollen grain types other than E. trifurca that can maximize pollen capture are not generally represented in the aerobiology of Ephedra during the pollination season. Therefore, the phenology of pollen release, community taxonomic-composition, and the physics of particle capture play collectively important roles in the reproductive success of Ephedra trifurca.

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  1. Batchelor, G. K.: An introduction to fluid dynamics. Cambridge University Press, Cambridge 1980

  2. Bierhorst, G. W.: Morphology of vascular plants. Macmillan, New York 1971

  3. Bold, H. C.: Morphology of plants, 2nd ed. Harper and Row, New York 1967

  4. Kauchan, S., Jayachandra: Pollen allelopathy a new phenomenon. New Phytologist 84, 739–746 (1980)

  5. Niklas, K. J.: The motion of windborne pollen grains around conifer ovulate cones: implications on wind pollination. Am. J. Bot. 71, 356–374 (1984)

  6. Niklas, K. J., Buchmann, S. L., Kerchner, V.: Aerodynamics of Ephedra trifurca: I. Pollen grain velocity fields around stems bearing ovules. Am. J. Bot., in press

  7. Paterson, A. R.: A first course in fluid dynamics. Cambridge University Press, Cambridge 1983

  8. Thomson, J. D., Andrews, B. J., Plowright, R. C.: The effect of a foreign pollen on ovule development of Piervilla lonicera (Caprifoliaceae). New Phytologist 90, 777–783 (1981)

  9. Vogel, S.: Life in moving fluids. Willard Grant Press, Boston 1981

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Niklas, K.J., Kerchner, V. Aerodynamics of Ephedra trifurca . J. Math. Biology 24, 1–24 (1986). https://doi.org/10.1007/BF00275718

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Key words

  • Aerodynamics
  • Pollination
  • Ephedra
  • Computer simulations