We have undertaken the analysis of 45 surface samples from the Lanoraie peat bogs (45°58′ N, 73°20′ W), situated in the Saint Lawrence lowlands. A reassessment of the different pollen sources that contribute to the pollen rain is carried out. According to the ecology of the species recovered, two principal classes are recognized; proximal and distal. Each of these classes is subdivided in two subclasses according to their extent. The punctual and local sources compose the proximal class, and the regional and zonal sources compose the distal class. The use of similarity and association indices permits the identification of the different distal sources. Thirty-five percent of the distal species are associated among themselves. We identify three habitats: forest, fields, and bogs. We also observe that pollen analysis recovers only those species that make the dominant strata. The characteristic species of Lanoraie are Quercus sp., Salix sp., and the grasses. The strongest pollen productors are Ambrosia artemisifolia (36%), the grasses (10%), and Pinus strobus (8%). We have also outlined the vegetation communities of the proximal class. These communities are discussed first from the point of view of the associations, then from the point of view of the species. According to their hydric characteristics, the elements of the pollen flora are grouped in three types. This inventory should permit a better interpretation of the pollen analysis results in terms of vegetation succession.
Pollen analysis of the surface samples of bottom sediments in the bay of Gdańsk
