BIOCLIMATIC FACTORS AFFECTING DAILY CUPRESSACEAE FLOWERING IN SOUTHWEST SPAIN

Daily variations in Cupressaceae pollen counts were analysed, together with climatic variables in the southwest of Spain, in order to unders tand the bioclimatic variables affecting Cupressaceae flowering in a M editerranean climate. The study was carried out using the Spanish Aero biology Network recommendations, using a Burkard Hirst-type spore trap . Regression analyses were applied to the pollen counts of the winter months of 13 consecutive years. The regression analysis applied to eac h year indicated that temperature is the most important variable to in clude in the model. Temperature affected the pollen counts differently according to the yearly climatic trend. During the coldest years, pol len counts depended on the minimum temperature, while in the warmest o nes they were affected by higher temperatures. However, during the dri est years, pollen counts depended more on the humidity level, while in the wettest years they depended more on the hours of sunshine.