Nocturnal accumulation of titratable acidity in Tillandsia makoyana (Bromeliaceae), epiphytic bromeliad of the tropical dry forest

The epiphytic bromeliad Tillandsia makoyana was studiedto assess the contribution of the environmental factors, water,temperature, and light, to the expression of the Crassulacean acid metabolism.In particular, nocturnal titratable acidity accumulation andmaximum leaf temperature were measured in response to wateringand incident light. Plants that were watered and exposed to directsunlight had the highest nocturnal accumulation of titratable acidity(25.52 ± 0.34 H+/m2), while those without irrigation and shadedshowed a 59% reduction in their titratable acidity. Our results illustrateda rapid response of the photosynthetic activity to water availabilityin Tillandsia makoyana, a native species from an ecosystemwhere this environmental factor fluctuates greatly.