To gain insight into the vegetation and climate of the past, proxy data of various types are used, one type being the distribution of plant pollen. Palynology is the study of pollen grains and spores (palynomorphs). Preserved in sediments, particularly organic sediments of lakes and wetlands, pollen provides information on the type of vegetation at the time of deposition. These data can then be related to past climate, based on comparisons with present-day vegetation and climate.

Spruce (Picea)	Heath (Ericaceae)
Sedge (Cyperaceae)	Pea (Leguminosae)

Sediments are recovered from deposits using a variety of coring devices. Sub-samples from the sediment cores are treated chemically in the laboratory, and the palynomorphs are then identified and counted under a microscope. The distinctive characteristics of the palynomorphs allow them to be identified and related to the plant taxa (species) from which they were derived. The abundance of each taxon gives an indication of the abundance of that plant on the landscape. Systematic analysis throughout the length of the core and age determinations by radiocarbon dating techniques lead to the production of a pollen diagram.

Authors: R.J. Mott and H. Jetté
Geological Survey of Canada