Nitrogen uptake and allocation in the sea grass Amphibolis Antarctica

Amphibolis Antarctica is an important sea grass along the south and southwest coast of Australia. The purpose of this work was to study how it acquires the nitrogen which it needs in order to sustain its observed high productivity despite the low nitrogen conditions in which it exists. The nitrogen uptake was examined for both leaves and roots by depletion of ammonium in split chamber experiments, and its capacity was compared to its requirements based on estimates from growth rates and tissue nitrogen concentration. The nitrogen uptake incorporation and re-distribution within the plants were studied in laboratory cultures by the Nitrogen 15 technique.