Aerodynamics of Saccate Pollen and Its Implications for Wind Pollination
Andrew B. Schwendemann
Dr. Jeffrey M. Osborn and Dr. Scott Thatcher, Faculty Mentors
The pollen grains of many wind-pollinated plants contain one to three air-filled bladders, or sacci. Sacci are thought to increase surface area, yet add minimal weight, thereby increasing dispersal distance. However, no studies have tested this hypothesis. Using scanning electron and transmission electron microscopy and mathematical modeling, a computational model has been developed to investigate pollen flight. Saccate pollen grains of three extant conifers (Pinus, Falcatifolium, Dacrydium) were used to create the model. Examples of structural characters analyzed include: lengths, widths, and depths of the main body and sacci; angle of saccus rotation; thicknesses of the saccus wall, endoreticulations, intine, and exine; and surface ornamentation. The model uses these data to calculate terminal settling velocity. The advantage of a mathematical model that is based on structural characters is that flight properties can be measured without having to physically test pollen, providing the opportunity to model flight dynamics of fossil pollen.
Keywords: pollen, mathematical model, aerodynamics, wind pollination, Mathematica, electron microscopy, conifers, fossil
Presentation Type: Oral Paper
Location: VH 1408