I propose an approach to provide 95% confidence intervals for a chronology of low-frequency tree-ring variation so that a level of significance or importance for trends can be inferred. The approach also visually reveals the portions of a chronology in which sample depth is so poor that low-frequency variation is not robustly estimated. A key characteristic of the approach is that it is essentially a reordering of the individual steps commonly used in constructing standard tree-ring chronologies; consequently, it is computationally simple for researchers who already routinely construct standard tree-ring chronologies. The most important ramification of the approach is that each year of the chronology has a distribution of smoothed index values with which to estimate confidence intervals around the chronology of low-frequency variation. It can be argued that the approach constitutes multiple significance testing of means, which causes the α level for the confidence interval to be unknown. Nonetheless, the approach is still useful in that it provides a way to evaluate the probable importance of low-frequency trends expressed in tree-ring chronologies.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/262287 |
| Date | January 1991 |
| Creators | Sheppard, Paul R. |
| Contributors | Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona |
| Publisher | Tree-Ring Society |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | Article |
| Rights | Copyright © Tree-Ring Society. All rights reserved. |
| Relation | http://www.treeringsociety.org |
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