Late quaternary insects and freshwater invertebrates of the alaskan north slope and paleoenvironmental reconstructions in arctic Alaska

Abstract

A large series (26 samples) of fossil insect assemblages were excavated from riverbank exposures at two localities at Ikpikpuk and Titaluk Rivers on the North Slope of Alaska, U.S.A. Climatic conditions were reconstructed for the Late Pleistocene and early Holocene based on the fossil insect assemblage data. Insects indicate the continuous existence of a steppe-tundra community on the Alaskan North Slope during the end of the Pleistocene and the beginning of the Holocene. The invasion of poplar during the Early Holocene occurred within the context of the steppe-tundra community. The insect faunas indicate plant communities dominated by grasses and other herbs, with the local presence of tall shrubs and dwarf willows. The composition of the North Slope insect communities during the study interval was affected by the high latitude of the localities, periglacial winds coming off Brooks Range glaciers, and the close proximity of eolian sand and silt. The North Slope environment differed from those in more southerly localities in Eastern Beringia, reflecting ancient climatic and vegetational zonation.