Age Estimation of Dracaena cinnabari Balf. f. on Socotra Island: A Direct Method to Determine Its Lifespan

Background: Dracaena cinnabari is a monocot species that does not form annual tree rings; thus, its age can only be estimated. This threatened by low natural regeneration, with an evident absence of younger individuals most likely caused overgrazing; therefore, knowing trees’ ages important for possible conservation strategies; Methods: Data collection was conducted on the Firmihin Plateau Socotra Island (Yemen) in 2021, and diameter at breast height (DBH) 1077 measured, same as those established monitoring plots 10 years before current measurement. The 10-year radial stem increment DBH obtained 2011 served basis linear model from which equations calculation were derived. Results Conclusions: A direct estimation D. developed. According to fit model, first (10.1–15 cm) class estimated 111 years, while last (90.1–95 672 years. results revealed previously used indirect methods accurate.