LAURA HITCHINGS

A Study of the Dispersal of Anemophilic Pollen, Concentrating on Grain Physical Parameters, such as Size and Density

My project was to study the dispersal of anemophilic (wind distributed) pollen, especially as referenced to the grain physical parameters such as size and density, so as to better the current understanding of pollen transport. This understanding improves how we interpret the pollen record, largely collected from lakes and bogs and such, for information such as paleoclimatic and paleovegetative reconstruction. Palynologists and limnologists look at pollen rich sedimentary rocks, identify known species, and from their ecological bounds, infer things about the paleoclimate. Yet if the pollen being looked at comes from some distance away, you only can infer the paleoclimate at some potentially unknown source distance, rather than the area you are studying. This research project sought to experimentally determine how six distinct pollen species would disperse in relation to each other and their physical characteristics. The results showed that at close distances from the release source, the volume of a typical grain plays a larger role in the number of grains deposited than any other factor, but that as distance increases, the effects of density increase, and the relative deposition for less dense grains increases from where it might have been close to release, when contending with larger grains. Cirain shape and texture were shown to have little supportable effect, largely attributed to the scale (micrometers) of the pollen compared to the scale of the wind and turbulent eddies. Another important result of this study is that interested researchers will know to put collection tape further downstream and closer together, and to attempt to isolate certain physical parameters by choosing species similar in all aspects but one, so as to assert conclusions more confidently.
 


 

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