Influence of land cover and structure of tree stands on pollen deposition in Zaborski Landscape Park

Abstract

The paper presents a comparison of modern pollen deposition in Tauber traps after one-year exposure at two research sites - Laska and Widno, located in the northern part of the Zaborski Landscape Park in the Pomerania Province (Northern Poland). The studied sites were circular in shape with a radius of 2 km and an area of 1256 ha each. They were characterised by similar contribution of forest and non-forest areas, as well as similar species composition and area covered by tree species. Both sites differed, however, in the location of traps in relation to forest areas and distribution of deciduous trees amid pine monocultures. At the former site, a Tauber trap was placed in the open field, i.e. in xerothermic meadow, in the western part of the Laska village. At the latter site, a trap was placed on the borderline between meadows of the Widno village and the surrounding forests. At the site of Laska, scattered deciduous trees occurred mostly in the form of small clusters amid extensive pine monocultures surrounding the village. Whereas at the site of Widno, deciduous tree species covered larger areas in the form of more fertile oak-hornbeam forests, beech forests and birch woods amid pine forests. The size of area covered by tree species and the amount of pollen deposition by these trees were positively correlated at both sites. In addition, the average annual pollen deposition was calculated for each site for seven most abundant tree species during the period of 1999-2010. By comparing the arithmetic means, it was found that the pollen deposition at the site of Widno is higher for most of the studied arboreal species compared with the site of Laska, but these differences are statistically significant only in the case of birch and hornbeam.