Drought indicated in carbon-13/carbon-12 ratios of southwestern tree rings

Stomatal closure during periods of moisture deficiency should theoretically lead to elevated 13C/12C ratios as reduction of available CO2 leads to diminished photosynthetic discrimination against 13C in favor of 12C. Stable-carbon isotope ratio chronologies developed from 5-yr tree-ring groups at 17 sites in six southwestern states were tested for a drought relationship by first fitting a spline curve to each chronology to remove the long-term trend and calculating indices as the ratio of actual to spline curve value. The time series of ?Del Indices? so developed are significantly correlated with 5-yr mean Palmer Hydrological Drought Indices (post-1930 period) and reconstructed July Palmer Drought Severity Indices...

Categories: Publication; Types: Citation, Journal Citation; Tags: C-13/C-12, Journal of the American Water Resources Association, Palmer Drought Indices, Pinus edulis, Southwest, All tags... drought, pinyon pine, stable-carbon isotopes, Fewer tags