Abstract

The aeropalynological sampling of March 2011 was carried out at Ayetoro-Itele, Ota, southwest Nigeria. This was done to create a basis for comparison with March 2010 aerofloral data and verify conclusions made there with respect to its strange haze dust. An improvised aerofloral sampler made up of a food flask base, plastic cylinder, 5 µm mesh sieve and sieve-clamp was mounted on a 2 m stand beside the position of the previous year (March 2010) data collection. Chemo-palynological treatment of the recovered sediment and microscopic analysis of its residue revealed a predominance of the aeroflora by Poaceae and Cheno/Am. There was no record of Vitex cf. doniana, Isoberlinia doka and Parinari spp – the Guinea/Sudan savanna vegetation species that dominated the previous year’s month. Almost all the pollen recovered was dry climate indicators unlike the 2010 data that recorded relatively high proportion of wet indicator pollen. Fungal elements and diatom species are of higher diversity but of lower population thus reflecting the autochthonous source of the sediment. These findings further support the conclusion that the haze dust of March 2010 was as a result of late harmattan triggered by an unknown event that brought the savanna pollen dominating its data.

Key words: Aeropalynology, harmattan, pollen and spores, fungal elements, diatom frustules.