Is the modern-day dieback of yellow-cedar unprecedented?

In Southeast Alaska, many stands of yellow-cedar (Callitropsis nootkatensis (D. Don) Oerst. ex D.P. Little; hereinafter “YC”) contain numerous standing, dead snags. Snag-age estimates based on tree morphology have been used to support the interpretation that a warming climate after ca. 1880 has triggered unprecedented YC dieback. Here, we present new snag longevity by cross-dating 61 snags with morphologies suggest they stood for extended periods. All but four these lost their outermost rings decay, so estimate when died using method wood-ablation rates measured in six living trees display partial cambial The results indicate ∼59% branches decay (Class 5 snags) remained standing >200 years, and some as long 450 years (snag mean ± SD: 233 92 years). These findings, along supporting evidence from historical photos, dendrochronology, snag-morphology surveys published literature episodes dieback also occurred before significant anthropogenic began. roles played change earlier events remain be further explored.