Persistence of growth variation in tree-ring chronologies

We infer baseline response to climate of the growth of trees in California dendroclimatological samples, adopting linear and nonlinear approaches and using the expected accumulated impact of a state change as one measure of persistence. Many samples exhibit two quite distinct growth states. Timing of high and low growth states is highly heterogeneous across locations, and regional aggregation seriously understates the size and persistence of local growth changes. If climate is a dominant factor in local tree growth, then local climate is not well represented by an aggregate regional index.