In this study, the atmosphere in Tulsa was monitored with a Burkard Spore Trap situated
on the roof of a building at the University of Tulsa, as seen in the photograph at the right. Microscope counts
were converted into average daily concentrations and expressed in grains/m³.
In totaling up the amounts of various pollen grains, several criteria were used to determine
patterns in the seasonal fluctuations. The Start Date of the season of each type of pollen was defined as 5% of
the cumulative season total, whereas the End Date was defined as 95% of the season total. The Peak Date of each
season was recorded as the date of maximum average daily concentration. The study was conducted from 1987 to 1996,
and the pollen levels for species of Betula, Quercus, Ulmus, Juniperus/Cupressaceae, Morus and Carya were examined.