DROUGHT INDICATED IN CARBON‐13/CARBON‐12 RATIOS OF SOUTHWESTERN TREE RINGS

Steven W. Leavitt, Austin Long

Research output: Contribution to journalArticle

71 Scopus citations

Abstract

ABSTRACT: 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 from respective areas. Overall, in the period since 1790, the driest pentads were 1900–04 and 1960–64, whereas the wettest were 1980–84 and 1915–19. Maps of drought represented for two pentads seem to be reasonable representations, although spatial correlations of Del Indices with PHDI were generally not significant. These Del Index drought reconstructions may provide a useful measure of past physiological response to drought (stomatal closure), although the present cost of analysis would prevent this from being a routine method.

Original languageEnglish (US)
Pages (from-to)341-347
Number of pages7
JournalJAWRA Journal of the American Water Resources Association
Volume25
Issue number2
DOIs
StatePublished - Apr 1989

Keywords

  • C‐13/C‐12
  • Palmer Drought Indices
  • Pinus edulis
  • Southwest
  • drought
  • pinyon pine
  • stable‐carbon isotopes

ASJC Scopus subject areas

  • Ecology
  • Water Science and Technology
  • Earth-Surface Processes

Fingerprint Dive into the research topics of 'DROUGHT INDICATED IN CARBON‐13/CARBON‐12 RATIOS OF SOUTHWESTERN TREE RINGS'. Together they form a unique fingerprint.

  • Cite this