Radiocarbon dating opens up new frontiers in the study of tree longevity: Insights from angiosperm trees

Long-lived trees support biodiversity at multiple scales, maintain ecosystem functionality, serve as natural archives, and hold cultural and aesthetic value. Despite their importance, the maximum longevity of many tree species remains poorly understood, limiting the design of effective conservation strategies. Challenges in obtaining reliable tree ages are commonly represented by natural wood decay, sampling obstacles, and indistinct or absent annual rings, which prevent or limit the application of tree-ring analyses (dendrochronology). Radiocarbon dating, increasingly accessible and applicable to all species, provides a flexible approach to study tree longevity and its ecological implications. For tropical trees, which mostly lack annual rings, radiocarbon dating is one of the few reliable methods to determine tree ages. Even in sections of the calibration curve characterized by oscillations and plateaus, statistical methods such as wiggle-matching or deposition models may be used to reduce the range of probable tree ages. In this paper, we illustrate a mismatch between tree-ring and radiocarbon-derived estimates of the longevity of angiosperm trees, with tree-ring maximum ages often half of those obtained through radiocarbon dating. We also present the most up-to-date estimates of maximum longevity for 42 arboreal angiosperm species worldwide, based on a literature review. Radiocarbon results indicate that ages of 400–500 years are a common feature of many broadleaved species, while exceptional old ages are restricted to a small minority of individual trees. Our results underscore the need for increased efforts to locate old and ancient trees, investigate their role in ecosystem ecology and ensure their protection.