A Spacio-Temporal Pattern of Pollen Sedimentation in a Dimictic Lake with Laminated Sediments

Resuspension in the main basin of Lake Gościąż results approximately a doubling of the total sedimentation rate in the deepest region. The increase pollen flux in bottom traps during overturn was more four times higher than in the upper traps. The most intensive pollen sedimentation was recorded before and just after freeze-up. This could only have been the result of previous sediment resuspension. Mechanisms of sedimentation in the studied lake showed that resuspension and resedimentation can change “the environmental record” of events even in a lake with laminated sediments. Higher sedimentation of pollen during autumn circulation confirmed that in the sediment layers (varves or laminae) particles from previous seasons also could have been found. In the bay pollen sedimentation was lower and depended on plant flowering, there was no resuspension.