Natural proxy records of hydroclimatic behavior, such as tree ring chronologies, are a rich
source of information of past climate-driven nonstationarities in hydrologic variables. In this study, we investigate tree ring chronologies that demonstrate significant correlations with streamflows, with the objective
of identifying the spatiotemporal patterns and extents of nonstationarities in climate and hydrology, which
are essentially representations of past ‘‘climate changes.’’ First and second-order nonstationarities are of particular interest in this study. As a prerequisite, we develop a methodology to assess the consistency and
credibility of a regional network of tree ring chronologies as proxies for hydrologic regime.
