View article

The consequences of acidity for plant performance are profound, yet the prevalence and causes of low pH in bromeliad tank water are unknown despite its functional relevance to key members of many neotropical plant communities.

We investigated tank water pH for eight bromeliad species in the field and for the widely occurring Guzmania monostachia in varying light. We compared pH changes over time between plant and artificial tanks containing a solution combined from several plants. Aquaporin transcripts were measured for field plants at two levels of pH. We investigated relationships between pH, leaf hydraulic conductance, and CO₂ concentration in greenhouse plants and tested proton pump activity using a stimulator and inhibitor.

Mean tank water pH for the eight species was 4.7 ± 0.06 and was lower for G. monostachia in higher light. The pH of the solution in artificial tanks …