No Long‐Term Decay in α‐Cellulose of Living and Relict Trees From the European Alps Over the Past 8,000 years

Tree‐ring α‐cellulose stable isotopes of living trees and dead woods are increasingly used for high‐resolution paleoclimate reconstructions spanning centuries to millennia. However, the potential effects of wood decay on α‐cellulose content (CC) and the composition of tree‐ring stable isotopes remain largely unexplored. Here, we present α‐cellulose content measurements from relict and living trees in the European Alps spanning the past 8,000 years. This study addresses whether preservation context alters the isotopic integrity of α‐cellulose. We assess the temporal stability of CC, its dependence on tree species, preservation conditions and wood type (subfossil, dry dead, living), as well as its relationship with α‐cellulose stable carbon, oxygen, and hydrogen isotopes (δ 13 C, δ 18 O, δ 2 H). Our results show that α‐cellulose remains stable over millennia under alpine conditions. Our results not only confirm the suitability of relict wood for tree‐ring stable isotopic analysis and paleoclimate reconstructions, but also provide insights for the improvement of global carbon cycle models.