Does vegetation mediate the fire-climate relationships in boreal regions?
Lynch, Jason*,1, Hu, Feng Sheng1, 1 University of Illinois, Urbana, Illinois ABSTRACT- Numerous paleoecological studies have provided information on Holocene vegetational changes in Alaska. However, the relationship between climate and vegetation composition on the boreal fire regime is poorly understood, because few charcoal records exist from that region. We analyzed sediment from Low Lake (62o 32.8′ N, 153o 36.8′ W) and Farewell Lake (62o 32.8′ N, 153o 36.8′ W) in the Alaska Range for lithology, ostracode trace-element composition, pollen, and charcoal to reconstruct climate, vegetation, and fire return intervals (MFI). Geochemical (Mg/Ca and Sr/Ca ratios) and lithological data suggest cold and dry climatic conditions between 13000 and 9500 calibrated years before present (BP), highest growing-season temperatures from 8800 to 5000 BP, and a major increase in effective moisture between 8500 and 6600 BP. Betula shrub tundra and Populus-Salixwoodland/forest dominated the early-postglac
