U. of California, Los Angeles Naturally occurring droughts are a chronic problem for agriculture and resource management in the Great Plains of the U.S. and Canada. Attempts to predict potential drought severity are hampered by the short length of most climatic records from the plains. The research proposed will utilize tree ring analysis to extract long term climatic records needed to establish baselines for assessing potential severity. The research project will obtain tree rings from living trees and subfossil wood at a number of sites in Alberta, Saskatchewan and Manitoba. These sites when combined with existing sites in the U.S. will form a truly comprehensive tree ring network of the plains for the first time. Tree ring chronologies based on ring widths and densities will be constructed for at least the last 500 years. Relations between precipitation, ring widths and density will be examined and transfer functions developed to reconstruct regional records of drought for this period of time. The resulting records will be analyzed to determine the comparative ability of latewood density as a predictor of precipitation, the severity of recent as opposed to older droughts, and drought occurrence patterns and periodicities in the northern plains. The research is both theoretical and applied.
