Growth–reproduction trade-offs are common but changing in woody plants: a meta-analysis

Growth and reproduction draw on a common resource pool, yet empirical studies of woody plants report widely differing relationships between seed production and growth. Here we synthesize 685 estimates from 78 studies covering 79 woody species to test how growth–reproduction correlations vary across time, species, and environments. Growth and reproduction measured within the same year were negatively correlated, suggesting an immediate cost of reproduction. Lagged growth–reproduction relationships further suggest that reproduction incurs delayed constraints on growth beyond the year of investment. The strength and direction of growth–reproduction correlations showed no detectable phylogenetic signal and were not systematically related to functional traits and climate. Instead, trade-offs were strongest in species with high interannual variability in seed production and weakened markedly over recent decades in these species. Together, these results show that growth–reproduction trade-offs in woody plants are common but not fixed, and that shifts in reproductive variability under environmental change can alter how trees balance growth and reproduction, with consequences for long-term forest functioning.