Acidity in the Tank: Effects of Abiotic Factors on the Acidity of the Water in Epiphytic Bromeliads
Authors:Kyle Fukui, Gretchen North
Mentor:Gretchen North, Professor of Biology, Occidental College
Tropical tank bromeliads are epiphytic canopy dwellers that use a rosette of intersecting leaves to capture and retain rainwater. This leaf formation creates a small, acidic oasis of water with a microenvironment unique to each bromeliad. The abundance and variability of the life that revolves around this microenvironment is highly dependent upon abiotic factors (Souza et al. 2006). Acidity tests performed on ten Guzmania monostachia in a clearing in a Costa Rican rainforest indicate that both the amount of light and the amount of rainfall that a plant receives play a key role in determining the acidity of water in bromeliad tanks. Bromeliads in low light conditions were found to be significantly more basic than high light bromeliads (K-S test, P = 0.059), while high levels of rain were found to raise pH. These connections provide valuable insight into the effects changing climate will have on the biological diversity surrounding the plants, as lower pH is generally correlated with decreased biodiversity (Goffredi et al. 2011). Due to the important relation between bromeliads and the biodiversity of tropical rainforests, a more complete understanding of the factors that influence these plants is warranted (Stuntz et al. 2002).