Pollen Accumulation Rates: Estimates from Late-Glacial Sediment of Rogers Lake

Absolute pollen deposition in a Connecticut lake over a 4000-year interval has been estimated from pollen frequencies in a core of late-glacial sediment dated by radiocarbon techniques. The rate of total sediment accumulation as measured after burial was statistically constant at 0.036 centimeter per year, but the rate of deposition of pollen grains onto the sediment increased from 600 to 900 grains 14,000 years ago to 9000 per square centimeter per year 10,000 years ago. A major increase in the deposition of tree pollen occurred about 11,500 years ago, at the beginning of the spruce pollen zone. Presentation of data in conventional (percentage) form masks the magnitude of this change and distorts many of the changes in accumulation rates for individual types of pollen; moreover it magnifies statistical variation in the herb zone where all pollen is scarce.