ABSTRACT: Tree-rings are the prime archive for high-resolution climate information over the past two millennia. However, the accuracy of annually resolved reconstructions from tree-rings can be constrained by what is known as climate signal age effects (CSAE), encompassing changes in the sensitivity of tree growth to climate over their lifespans. Here, we evaluate CSAE in SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00468-024-02598-3.