COS 118-6 - The potential impacts of Native American land-use on fire regimes and forest structure in the Lower Klamath River Region, California

Thursday, August 11, 2011: 3:20 PM
18B, Austin Convention Center
Jeffrey N. Crawford1, Scott A. Mensing1, Frank K. Lake2, Carl Skinner3 and Susan Zimmerman4, (1)Geography, University of Nevada, Reno, (2)Pacific Southwest Research Station, U.S. Forest Service, Orleans, CA, (3)US. Forest Service, Pacific SW Research Station, (4)CAMS, Lawrence Livermore National Lab

Our study tests the hypothesis that Native Americans in the Klamath Mountains of northwestern California significantly influenced forest composition and structure through the extensive use of fire. Most existing regional paleo-fire and vegetation studies have been conducted at high elevations away from Native American settlements and identify climate change as the primary factor controlling forest change. This study examines two low elevation lakes, Fish Lake and Lake Ogaromtoc, which are near documented Native American settlements (3-5km), but still far enough away that evidence of Native American burning should only be recorded if populations were manipulating the landscape beyond the Klamath River. We use pollen and charcoal analysis to reconstruct paleo-vegetation and paleo-fire histories at each site over the past 3000-3500 years. Fire scars are used to compare with the charcoal record and examine the frequency of modern fires. Past Native American influences are evaluated by analyzing whether past vegetation changes and fire occurrences are consistent with regional climate reconstructions or whether changes in vegetation and fire occurrence are more consistent with shifts in Native American occupation and land use. 


Preliminary evidence indicates that the two lake sites exhibit fire signals that are not entirely congruent with regional climate reconstructions. These anomalous fire signals may be attributable to changes in Native American land use related to regional population shifts and technological changes within the last 2000 years. If Native Americans were burning regularly beyond their immediate settlements, forests at the time of European contact could reflect a human-modified landscape and not a landscape shaped by climate alone.

Copyright © . All rights reserved.
Banner photo by Flickr user greg westfall.