The pattern of seed banks during secondary succession on poor soils

Abstract

Studies on the soil seed banks of fallow lands of different ages were carried out on poor soil abandoned fields and in a fresh coniferous forest in north-eastern Poland. The size and diversity of seed banks was studied with the seedling emergence method. Species abundance (<em><strong>i</strong></em>), density (<em><strong>ii</strong></em>), number of species from different biological groups (<em><strong>iii</strong></em>) and distribution and mean <em>LI</em> value (<em><strong>iv</strong></em>) were analysed as the function of fallow land age. It was found that: (<em><strong>i</strong></em>) species diversity, number of species and ln of density are linear declining function of the fallow land age; (<em><strong>ii</strong></em>) for approx. 25 years the share of diaspores of identified species groups has been relatively similar. Seed banks of 40-50-year-old fallow lands are dominated by <em>Calluna vulgaris</em>, while the seed bank of the old fresh coniferous forest is dominated by dicotyledonous perennials and grasses; (<em><strong>iii</strong></em>) within the first 50 years of succession the persistence of seed banks measured by the Longevity Index increases gradually.