Rowan has fleshy fruits dispersed mainly by birds (Raspe et al. 2000). The variation in fruit production of rowan exhibits a wide range among trees (Żywiec et al. 2012; Bogdziewicz et al. 2024., Kondrat et al 2024). Fecundity of rowan is significantly related to plant size and increases with trunk diameter  (Bogdziewicz et al. 2020), and dbh is a slightly better predictor of individual fecundity than tree height (Kondrat et al. 2024). After accounting for dbh, variation among individuals in fecundity is influenced by light availability and conspecific neighbourhood crowding, while soil nutrient availability and elevation do not affect fecundity (Kondrat et al 2024). There is decline in reproductive investment just before death (Pasendorfer et al 2019).