LATE-GLACIAL CLIMATE AND ECOLOGY OF A KETTLE SECTION AT BRAMPTON, ONTARIO, CANADA, AS DETERMINED FROM FOSSIL COLEOPTERA

A 5 m sequence of organic-rich sediments (ca. 13 000 years BP to ca. 4 500 BP) from a drained glacial kettle pond near Brampton, Ontario, has yielded a rich and varied assemblage of coleopteran fossils. This pap er discusses the beetles recovered from the basal 1 m of the section ( ca. 13 000 to 12 500 BP), which represent the earliest phase of deposi tion in the kettle, prior to the final melt-out of underlying ice. The species are typical of northern boreal or tree-line habitats today. T hey illustrate that during this time the landscape was predominantly o pen ground, with herb and shrub vegetation. Individual trees or isolat ed clumps of conifers were nearby, as suggested by the presence of sco lytids (bark beetles). The mean July temperature was in the range from 12.5 to 15 degrees C, indicating that the lack of trees is a lag effe ct in colonization, perhaps due to unsuitable substrate conditions rat her than to an unfavourable climate.