Tree-Ring Evidence for Great Plains Drought

Abstract

A new collection of tree-ring chronologies developed from trees and remnant material located in the western and central Great Plains makes an important contribution to the spatial coverage of the US tree- ring chronology network. Samples from 24 sites were collected from the west-central Great Plains, and to date, ten chronologies have been produced. When correlated with a set of 47 single-station PDSI records, the chronologies display relationships with regional spring and summer drought. The reconstruction of spring PDSI for eastern Colorado generated in this study suggests that the inclusion of Great Plains trees can improve the quality of Great Plains drought reconstructions. The eastern Colorado drought reconstruction explains 62% of the variance in the instrumental record and extends to 1552. This reconstruction provides information about the regional character of major droughts over the past four and a half centuries. Major eastern Colorado droughts include events in the 1580s, 1630s, 1660s, 1730s, and the 1930s. The late 16th century drought, noted as an especially severe drought in the southwestern US, appears in this reconstruction as only slightly more severe than other major droughts in this region.