Short reproductive periods dominate mast seeding across diverse tree species

Mast seeding, synchronous and highly variable reproduction among perennial plants, profoundly impacts ecosystem dynamics and species interactions. However, the extent of periodicity in mast seeding, defined as cyclical but not strictly regular intervals between reproduction, remains poorly understood, including how it varies across and within species. Here, we used autoregressive analyses on seed production data from 556 populations across 20 tree species, with an average time series length of 19 years (range: 10–62 years), to quantify the prevalence and length of masting periods. We found widespread periodicity, predominantly characterised by a short period of 2–3 years. Although periodicity was common, the signal was often weak, indicating limited explanatory and predictive power. This period length aligns with theoretical predictions that balance the ecological benefits of predator satiation, effective mainly against specialized short-lived insect predators, with costs such as missed reproductive opportunities and resource losses. Extended period lengths (more than 4 years) were uncommon (2%), suggesting that longer periods may be less ecologically advantageous or subject to specific local conditions. Climate and elevation have limited and species-specific effects on period length and strength, implying local adaptation in cue sensitivity and resource accumulation. Our findings emphasise the adaptive value of short reproductive periods in mast seeding, likely reflecting consistent evolutionary constraints on reproductive timing across diverse ecological conditions.