Differential Pollen Accumulation in Water‐Tank Sediments and Adjacent Soils

Significant differences were found in pollen composition of sediments at different compass directions within large water—storage tanks. The center and north side were closest to the mean for the entire tank. Tank sediments showed an over—representation of arboreal pollen when compared with surface soil samples adjacent to the tank. The lower percentage of nonarboreal pollen in tanks was due to a lower percentage of Chenopodiaceae, Amaranthus, and Gramineae pollen. Miscellaneous arboreal taxa were present in tank sediments but not in soil samples.