A Reconstruction of Plant Species Composition at the Devil's Kitchen Site (Southern Oregon Coast) using Plant Opal Phytoliths and Charcoal Macro-remains

by Nicholas H Bulder

Institution: Oregon State University
Year: 2016
Keywords: phytoliths; Vegetation dynamics  – Oregon  – Pacific Coast  – History
Posted: 02/05/2017
Record ID: 2124010
Full text PDF: http://hdl.handle.net/1957/58559


Although plant remains, such as opal phytolith and charcoal analyses, have been used since the beginning of the 20th century to reconstruct past environments by ecologists and botanists, only recently have these techniques been considered by archaeologists in understanding the past at the site level. This study employs opal phytolith analysis with charcoal analysis to determine both the plant community composition and the possible use of tree species by humans at the site of Devil’s Kitchen (Southern Oregon coast) across the time interval of ca. 11,600 to 1,900 Radiocarbon Years Before Present (RCYBP). A total of 44 phytolith sample slides and 73 charcoal samples were analyzed from 5 lithostratigraphic units representing different depositional environments reflecting the site's distance from the ocean and elevation above sea level. This is due to the dynamic nature of landforms on the Oregon Coast, which since the last glacial maximum, have been influenced by sea level rise, tectonic uplift, and coseismic subduction. This dynamic landscape is confirmed by the botanical evidence. Charcoal macro-remains from the oldest sediments (10,638 ± 35 to 11,698± 38 RCYBP) indicate a forest of Douglas-fir and western hemlock. Phytolith evidence from later sediments (4,274± 26 to 1,901± 28 RCYBP) shows first, a mixture of saltwater inundation tolerant saltgrass and non-inundatuion tolerant fescues, followed by a period of time when only saltgrass is present. The site then returns to a mixture of saltgrass and fescue (ca. 2101± 23 RCYBP), until the site is buried by sand dunes.This updated perspective on the plant species surrounding the site through time provides important information on habitat and resources, and will assist archaeologists in interpreting other aspects of the archaeological record by placing artifacts in the environmental contexts in which they were used. Advisors/Committee Members: Minc, Leah (advisor), Davis, Loren (committee member).