Occurrence of pollen and spores in relation to present-day vegetation in aDutch heathland area

Pollen, spores and fungal remains in moss cushions along a transect, traver sing a Betula-Quercus forest and a surrounding heathland, were analysed in order to study the relation between present-day vegetation and recent polle n deposition. Pollen and spores are divided into local types from plant spe cies encountered along the transect and regional types, not present along t he transect. Relative percentages and absolute concentration of the palynom orphs were estimated. Radiocaesium activity in the moss was measured to ass ess the minimal duration of palynomorph accumulation (i.e. the age of the m oss samples). The absence of simultaneous trends in the regional pollen types indicates t hat the samples do not have major differences in age. The moss represents t he later stages in the heath mosaic cycle. This is supported by the radioca esium content of the moss. Thus, in this case the concentration values of r egional pollen approach deposition values. The values of the local pollen t ypes calculated on such a rather constant regional pollen flux is considere d to represent real differences in the local deposition. The local pollen types can be arranged topographically into five groups cha racteristic of the local vegetation types and their ecotones. The arrangeme nt of the curves of types from phyco-, zoo-, and myco-coenoses suggests the ir possible origin, either locally from the heath area or from the Betula-Q uercus forest, or regionally from elsewhere. Analyses and topographical arr angement of the curves of unknown types contribute in this way to their ide ntification and their possible source of origin.