Getting to the Root of Nutrient Uptake: An Unrecognized Function of Aerial Roots in Tank Epiphytes
Abstract
Very little is known about nutrient uptake in the tanks of bromeliads compared to their roots. The tanks, called phytotelmata, are created by their rosette leaf arrangement in order to store precipitation. When litter, dead insects, or any other forms of detritus fall into the tanks, organic matter is decomposed and releases nutrients to be absorbed by the plant, making the tank the primary source of nutrient uptake. It is, however, uncertain whether or not the root systems of these plants can also aid significantly in nutrient uptake, rather than only acting as an anchor to a substrate. In this study, at The University of Georgia Tropical Plant Conservatory, we studied a common species of tank bromeliad, Neoregalia spp ., in order to test the efficiency of root-based nutrient uptake. Three treatments were applied to bromeliads of similar size and shape (n=18) with the first set (n=6) being untreated. In the next set, the tanks of bromeliads (n=6) were completely filled with a 1000 mg/L concentration of Rb solution and the final set of bromeliads (n=6) had their roots drenched with the same solution. Rubidium was used as a tracer due to its similar physicochemical properties to potassium, a well-known mobile element in the plant system.
To compare the concentrations of rubidium found in plant tissue, a leaf was sampled from each bromeliad and processed by wet digestion for analysis by a mass spectrometer. We hypothesized that leaf concentrations of the Rb-spiked tank treatment will be larger than that of the concentrations found in the Rb-drenched root treatment, along with a significant amount of Rb absorbed by the roots. This would provide new evidence that aerial roots serve a greater function than only anchoring the plant to a substrate, calling attention to the lack of knowledge on the roles that aerial roots can play in bromeliad nutrient absorption.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMB081.0009G
- Keywords:
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- 0414 Biogeochemical cycles;
- processes;
- and modeling;
- BIOGEOSCIENCES;
- 0416 Biogeophysics;
- BIOGEOSCIENCES;
- 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCES;
- 0476 Plant ecology;
- BIOGEOSCIENCES