Phenolics lie at the center of functional versatility in the responses of two phytochemically diverse tropical trees to canopy thinning

Saplings in the shade of the tropical understorey face the challenge of acquiring sufficient carbon for growth as well as defence against intense pest pressure. A minor increase in light availability via canopy thinning may allow for increased investment in chemical defence against pests, but it may also necessitate additional biochemical investment to prevent light-induced oxidative stress. The shifts in secondary metabolite composition that increased sun exposure may precipitate in such tree species present an ideal milieu for evaluating the potential of a single suite of phenolic secondary metabolites to be used in mitigating both abiotic and biotic stressors. To conduct such an evaluation, we exposed saplings of two unrelated species to a range of light environments and compared changes in their foliar secondary metabolome alongside corresponding changes in the abiotic and biotic activity of their secondary metabolite suites. Among the numerous classes of secondary metabolites found...