PHYTOLITHS FROM TUNDRA PLANTS ON SANAK ISLAND, WESTERN GULF OF ALASKA

The Aleutian archipelago demarks the southern margin of Beringia and has played an important role in the migration of plants and animals during the late Pleistocene and Holocene. In this study we analyzed the modern vegetation of Sanak Island, the eastern-most island in the Aleutian Island archipelago, for phytoliths-microscopic particles of silica produced by plants. The aim of our study was to examine and catalogue phytoliths from species of maritime tundra to enhance our understanding of phytolith morphology and to provide a more robust catalog of new- and possibly old world phytoliths. We catalogued phytolith morphotypes and phytolith production of common, mostly native flora from maritime tundra on Sanak. A reference collection was established from 59 selected plant species belonging to 27 families. We examined 32 forbs, nine grasses, one sedge, two rushes, and 15 shrubs. We found that 76% of the plants produced no or only trace amounts of phytoliths and the remaining 24% had common to abundant production. These results expand the use of phytolith analysis in the Arctic and Sub-Arctic and support the utility of using phytoliths as indicators of tundra plant communities. This reference collection also offers the potential of phytolith analysis for paleoenvironment and paleoclimate reconstruction in this region.