Een palynologisch onderzoek van in dekzand ontwikkelde bodemprofielen

The relation was studied between vegetational development and soil formation in the Pleistocene cover sands in the Netherlands, particularly whether forests, rather than heaths, were early involved in the formation of podsolic soils. The pollen content of profiles of various podsols and some gleys were examined, all lying below layers of drift sand and peat of various ages. Beyerinck's palynological method had to be extended with a study of the significance of sand diagrams. In an undisturbed podsol pollen decreased in concentration roughly geometrically from the sand surface downward.A relation could be observed between the length of the vertical distribution of pollen (pollen profile) and the depth above, in which the original stratification of the Eolian cover sand had entirely disappeared.It was concluded that most of the pollen permeated before podsolisation, during the biologically very active stage of the homogeneous forest profile. The lowest part of the pollen profile, already fixed, constantly 'grew' on the top through addition of continually younger spectra; in later degradation stages illuviation of pollen could also become significant. A paucity of tree pollen in the whole spectrum could occur after various types of vegetation and after certain conditions of soil moisture.During the Boreal, Atlantic and Fagus-Carpinus period both homogeneous forest profiles and podsolic profiles occurred under diverse vegetation. During each of these periods homogeneous forest profiles were degraded to new podsolic profiles.