Data from: <b>Competition induces higher intraspecific trait variability in inferior than in superior tree species</b>

Multiple theories suggest that intraspecific trait variability can promote species coexistence only when the competitively inferior species exhibits a higher intraspecific trait variability than their superior counterparts, known as the interspecific mean-variance trade-off. However, whether this trade-off exists remains unknown. We evaluated intraspecific variability and plastic response of 10 traits from 6750 seedlings of 10 tree species in a 3-year competition experiment. No trade-off is found in competition-free homogenous environments, yet it emerges when seedlings are subjected to interspecific competition and in spatially heterogeneous environments. This is primarily driven by the plastic response of inferior species, which exhibits a greater increase in trait variability, particularly in fine-root traits, to competition. Our findings reveal the contextual dependence of the interspecific mean-variance trade-off and identify one driver of the trade-off. Furthermore, the distinct responses of competing species provide a novel perspective for comprehending their impact on species coexistence.