Pollen analysis is a method for reconstructing the past vegetation history in a particular area or context. As we know that vegetation cover in particular areas has altered over time, the technique used to be used as a generalized dating method.  However the development of more precise dating methods, such as radiocarbon-dating and dendrochronology, has meant that that aspect of pollen analysis has faded away.

All flowering plants produce pollen.  The external structure of individual pollen cells (their ‘walls’) are resistant to decay and hence very long-lasting.  In addition the form of these cells is individual to each type of plant, making them relatively easy to recognize and distinguish.  Therefore, a sample of pollen from an ancient context can give us a very good idea of the type of vegetation that grew in the vicinity at the time in question.  Questions such as the type of tree cover, changes in local vegetation, the presence or absence of agriculture etc. can often be addressed by analysis of the relative representation of the pollen found at a particular archaeological site.    

Pollen analysis is sometimes referred to as palynology, however that term actually describes the somewhat wider study which includes other microscopic remains of plants.

Lakes and bogs provide the perfect environment for the preservation of such remains.  In addition the incremental nature of sediment accumulation in such environments, provide us with a clear indication of change over time.  An ideal situation arises when, in the absence of good pollen preservation at an archaeological site itself, that site is located close to a lake or bog such as at the Discovery Programme Lake Settlement Project excavations at Derragh Island, Co. Longford and the Medieval Rural Settlement Project excavations at Tulsk and Carns, both in Co. Roscommon (see pages in Research section).