MODERN POLLEN DEPOSITION IN THE TAXUS RESERVE IN THE WIERZCHLAS (NORTHERN POLAND)

Modern pollen deposition and its relationship to the surrounding vegetation have been investigated in the Yew-trees Reserve. This study area is located in Northern Poland, app. 40km to the West of the Vistula River in the Tuchola Forest. On the local scale this multispecies forest is a peculiarity when compared to the monoculture of pine trees that surround it. The first aim of polynolgical research that was carried out in the reserve was to provide an explanation to the history of yew stand within this area. The research originally focused on the analysis of biogenic sediments from Mukrz Lake. However, the analysis of fossil samples showed a small representation of pollen grains of Taxus. Pollen analyses of the forest litter taken from various habitats in the reserve and of the surface layer of the bottom sediments of Mukrz Lake were made. The samples from the bottom of the Mukrz Lake also showed low percentage of the yew. The comparison of the surface spectra from different habitats of this reserve reflected big discrepancy in the presence of the yew pollen grains. On the one hand, these differences are related to the habitat from which the material originated, but on the other hand, they are related to the distance between the site from which the sample was taken and the location of a male species. The biggest percentage of the yew is noted in the samples originating from the Tilio-Carpinetum assemblage and the lowest percentage in alder forests and meadow, which corresponds to the absence of the yew in these plant assemblages. The differences in the yew percentage, which appear within the Tilio-Carpinetum assemblage, depend on the distances from the male species of yew. The big participation of yew pollen grains appears in the spectra that represent samples taken directly from under the tree crown and decreases gradually with the increased distance. Since 1997 (5 seasons) the examination of annual pollen rain has been conducted in accordance Pollen Monitoring Programme recommendations. Three pollen traps were placed in the different types vegetation The biggest amount of pollen grains that deposited on 1cm2 surface during one season was in the forested area trap. Multy-angled research approaches make it possible to compare the relationship between pollen deposition and local vegetation.