Trait‐associated pathway links plant diversity to litterfall phenology in a seasonally dry tropical forest

Phenology plays a central role in regulating energy flow and nutrient cycling, yet remains insufficiently integrated into biodiversity–ecosystem functioning frameworks. This gap is especially relevant in strongly seasonal systems, where community‐wide synchrony in leaf litterfall may arise from either temporal niche differentiation among species or convergence toward shared drought‐avoidance strategies. Here, we examined how plant diversity components and abiotic conditions shape phenological strategies and, in turn, community‐level litterfall synchrony in a seasonally dry tropical forest. Using structural equation modelling, we assessed the direct and indirect effects of plant species richness and evenness and soil moisture and fertility on phenological traits (temporal niche overlap and dominance of deciduousness) and community litterfall synchrony. We identified two contrasting diversity‐associated pathways. Higher species richness reduced temporal niche overlap, consistent with phenological complementarity, whereas higher evenness increased the dominance of seasonally concentrated litterfall strategies, reflected in higher dominance of deciduousness. Only this convergence pathway significantly increased litterfall synchrony. Soil moisture reduced both species richness and evenness, and soil fertility increased richness, indicating that resource gradients influenced litterfall synchrony primarily through their effects on diversity structure rather than through direct effects on phenological traits. Together, these findings suggest that litterfall synchrony in this system is driven primarily by shifts in functional dominance associated with species evenness rather than by phenological niche differentiation.