Climate Variability and Pollen: More Hay Fever or Less?

Abstract

RationaleAlthough studies have documented the effects of global warming on the pollen season, the influence of extreme weather and year to year climate variability must not be overlooked. This study examined the effects of the extreme heat and drought in Oklahoma during the summer of 2011 as well as the unusually warm winter of 2011-12 on airborne pollen levels.MethodsThe atmosphere has been monitored with Burkard samplers in Tulsa, Oklahoma since December 1986. Standard methods were used to collect, process, and analyze Burkard samples. Sampling data were log transformed prior to statistical analysis.ResultsIn Oklahoma, the summer of 2011 was the hottest on record, and the 2011-12 winter temperatures were the third warmest. The hot summer resulted in lower ragweed levels in fall. The cumulative seasonal ragweed pollen total for 2011 was 8106 compared to the 24 year average of 12364. The mean daily concentration for the 2011 season (103 pollen/m3) was significantly lower (t(77) = 7.306, p<0.0001) than the collective mean for the previous 24 years (159 pollen/m3). By contrast, the warm winter resulted in an earlier pollen season for many spring pollinating trees. Season start date for various trees was up to 20 days earlier than the 24 year average. Season end was also early for several pollen types; therefore, season length did not differ for most taxa.ConclusionsAlthough global warming may alter the phenology and distribution of plants, climate extremes may have more abrupt and dramatic effects of pollen levels. All of which can affect sensitive individuals. RationaleAlthough studies have documented the effects of global warming on the pollen season, the influence of extreme weather and year to year climate variability must not be overlooked. This study examined the effects of the extreme heat and drought in Oklahoma during the summer of 2011 as well as the unusually warm winter of 2011-12 on airborne pollen levels. Although studies have documented the effects of global warming on the pollen season, the influence of extreme weather and year to year climate variability must not be overlooked. This study examined the effects of the extreme heat and drought in Oklahoma during the summer of 2011 as well as the unusually warm winter of 2011-12 on airborne pollen levels. MethodsThe atmosphere has been monitored with Burkard samplers in Tulsa, Oklahoma since December 1986. Standard methods were used to collect, process, and analyze Burkard samples. Sampling data were log transformed prior to statistical analysis. The atmosphere has been monitored with Burkard samplers in Tulsa, Oklahoma since December 1986. Standard methods were used to collect, process, and analyze Burkard samples. Sampling data were log transformed prior to statistical analysis. ResultsIn Oklahoma, the summer of 2011 was the hottest on record, and the 2011-12 winter temperatures were the third warmest. The hot summer resulted in lower ragweed levels in fall. The cumulative seasonal ragweed pollen total for 2011 was 8106 compared to the 24 year average of 12364. The mean daily concentration for the 2011 season (103 pollen/m3) was significantly lower (t(77) = 7.306, p<0.0001) than the collective mean for the previous 24 years (159 pollen/m3). By contrast, the warm winter resulted in an earlier pollen season for many spring pollinating trees. Season start date for various trees was up to 20 days earlier than the 24 year average. Season end was also early for several pollen types; therefore, season length did not differ for most taxa. In Oklahoma, the summer of 2011 was the hottest on record, and the 2011-12 winter temperatures were the third warmest. The hot summer resulted in lower ragweed levels in fall. The cumulative seasonal ragweed pollen total for 2011 was 8106 compared to the 24 year average of 12364. The mean daily concentration for the 2011 season (103 pollen/m3) was significantly lower (t(77) = 7.306, p<0.0001) than the collective mean for the previous 24 years (159 pollen/m3). By contrast, the warm winter resulted in an earlier pollen season for many spring pollinating trees. Season start date for various trees was up to 20 days earlier than the 24 year average. Season end was also early for several pollen types; therefore, season length did not differ for most taxa. ConclusionsAlthough global warming may alter the phenology and distribution of plants, climate extremes may have more abrupt and dramatic effects of pollen levels. All of which can affect sensitive individuals. Although global warming may alter the phenology and distribution of plants, climate extremes may have more abrupt and dramatic effects of pollen levels. All of which can affect sensitive individuals.