NPS Paleontology Research Abstract Volume


HOLOCENE PALEOECOLOGY OF AN ESTUARY ON SANTA ROSA ISLAND,
CHANNEL ISLANDS NATIONAL PARK

Kenneth L. Cole
NPS - CPSU
115 Green Hall
Department of Forest Resources
University of Minnesota
St. Paul, MN 55108

A 5 meter sediment core was taken from a small estuary at the eastern end of Santa Rosa Island, within Channel Islands National Park, California. The core produced a stratigraphic and pollen record spanning the last 5200 years. Three major zones, distinguished through pollen analysis and sediment chemistry, are visible in the core. The lowermost zone (5200 to 3436 yr B.P.) represents a time of arid environments with predominantly marine sediment input and high Cheno-AM and Ambrosia pollen values. The next zone (3319 yr B.P. to 1800 A.D.) is characterized by greater fresh water input with high values for Compositae, Cyperaceae, and charcoal particles. The uppermost zone (1800 A.D. to present) documents the vegetation disturbances and high sedimentation rates which resulted from the introduction of large exotic herbivores and exotic plants to the island during the settlement period. The identification of pollen grains from a nearby stand of Torrey Pine (P. torreyana), one of only two natural stands, document its persistence on the island throughout the late Holocene.



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United States Department of the Interior, National Park Service