Palinologia do componente herbáceo na atmosfera de Caxias do Sul, RS, Brasil

Abstract

This study was carried out in the city of Caxias do Sul, from January 1, 2001 to December 31, 2002 and aimed to identify pollen types and seasonal fluctuation of herbaceous taxa in the atmosphere. The city is located on the Upper Northeast Slopes in Rio Grande do Sul State. The climate is tropical with seasonal rainfall and there are three different types of vegetation: mixed ombrophilous forest, deciduous forest and grassland. Pollen monitoring was done with a Burkard® volumetric spore-trap sampler placed on top of the Hospital Geral, about 20m above ground level. During the study period 40 pollen types were identified, 11 from herbaceous taxa, which represents 23.22% of the total number of grains collected. Maximum concentration of herbaceous taxa was registered in October and November. The Poaceae R.Brown pollen type had the highest incidence, followed by Cyperaceae Juss., Plantago L., Amaranthus L., Rumex L., Iridaceae Juss., Brassicaceae Burnett, Apiaceae Lindl., Alternanthera Forssk., Convolvulaceae Juss. and Caryophyllaceae Juss.