Yellow rain on the ridge of Uludag mountain, nw-Turkey

Abstract

In this study, atmospheric pollen grains investigated with the gravimetric method in years 2014 and 2015. Annually 12158 pollen grains, belonging to 52 plant taxa identified and pollen grains of woody taxa consist of 93.30% of the annual pollen index, which found concordant and evaluated as a reflection of the dominated flora and vegetation of the area. Pollen types belonging to Pinus, Quercus, Cupressaceae/Taxaceae, Cedrus, Poaceae, Plantago and Abies were classified as dominant pollen types for the region and the total amount for them were 94.37% of annual pollen index. Of these, 59.87% of dominated pollen types belonging to Pinaceae family members and can be shown as a reason for high yellow rain in the study area. It was noted that Gymnosperm trees such as Pinus, Cupressaceae/ Taxaceae, Cedrus and also Quercus, which produce excessive amounts of pollen were particularly affected by rainfall and humidity in their pollination period. The month, in which pollen was the highest in the year, was recorded as April in both sampling years. April-May term found as an overlap of pollination periods and can be thought as a risky period for sensitive individuals for the region.