Absolute Pollen Counting

Absolute pollen counting is the determination of the number of grains of each pollen type per unit weight (grains/gram) or unit volume (grains/cm3) of sample. Variation in the rate of sedimentation sometimes makes the number of years represented uncertain; absolute counts for different samples may therefore not be compatible. Pollen analysis is then calibrated with radiocarbon dating to create pollen influx rates figured by the number of grains of each pollen type accumulating on a unit area of lake or bog surface in one year (grains/cm2/year) for each sample.

Pollen analysis may be carried out by determining the number of grains of each pollen type per unit weight (grains/gm) or unit volume (grains/cm3) of sample. This is called absolute pollen counting, and avoids some of the problems of PROPORTIONAL POLLEN COUNTING, although it is rather more time-consuming. Variation in the rate of sedimentation leads to uncertainty about the number of years each sample represents, and absolute counts for different samples may therefore not be compatible. This has led to the use of pollen influx rates, where a pollen analysis is carefully calibrated by radiocarbon dating, and the number of grains of each pollen type accumulating on a unit area of lake er bog surface in one year (grains/cm2/year) is calculated for each sample.