FLOWERING OF URBAN TREES AND AIRBORNE POLLEN CONCENTRATIONS IN DIAMANTE (ENTRE RÍOS, ARGENTINA)

Anabella Sánchez & Fabiana Latorre

Abstract

Flowering is one of the most important events of a plant’s life cycle. The seasonality, intensity and progress of flowering phases vary within and between years. This variability is detected by atmospheric pollen records as variations in the amount and type of pollen grains. In this study, the flowering rhythms of the most important urban tree species of Diamante were analysed during a reproductive cycle. Flowering curves were compared with airborne pollen curves. The effects of weather conditions as well as the pollination strategies were evaluated. Tabebuia impetiginosa, Tecoma stans, Melia azedarach, Brachychiton populneus and Fraxinus pennsylvanica were the analysed species. Floral phenologic developments of T. stans and M. azedarach were homogeneous. F. pennsylvanica showed high floral variability however, the pollen curve coincided with flowering curve. Some distinctive features between anemophilous and entomophilous species were established in relation to flower development as well as its representation in the atmospheric pollen spectrum.