HR: 0800h
AN: B11A-1010    [Abstracts]
TI: Persistence of El Niño effects on stable isotope ratios in cellulose of Coast Redwood tree-rings
AU: * Johnstone, J A
EM: jajstone@berkeley.edu
AF: Department of Geography University of California, Berkeley, 507 McCone Hall, Berkeley, CA 94720 United States
AU: * Johnstone, J A
EM: jajstone@berkeley.edu
AF: Center for Stable Isotope Biogeochemistry, University of California, Berkeley, Berkeley, CA 94720 United States
AB: An anomalously wet El Niño winter in 1998 in Sonoma County, California, USA produced sharp changes in the oxygen and carbon isotope ratios of tree-ring cellulose of Coast Redwood ( Sequoia sempervirens (D.Don) Endl.) which persisted for several years thereafter. High-resolution cellulose sampling reveals a negative shift in both δ¹⁸O and δ¹³C, consistent with greater reliance on winter rain water supplies (rather than summer fog) as well as reduced drought stress due to the anomalous precipitation. The annual cycle of these isotopic ratios is also muted for several years following the 1998 winter. These observations suggest a disproportionate and persistent influence of extreme years in the interannual variability of Coast Redwood hydrology and physiology.
DE: 0454 Isotopic composition and chemistry (1041, 4870)
SC: Biogeosciences [B]
MN: Fall Meeting 2005