Physiological responses by juvenile Egregia menziesii (Phaeophyta) to simulated effects of wave action: Carbon and nitrogen uptake and carbon partitioning

Although biomechanical and morphological adaptations to different wave energy regimes are well known, the physiological mechanisms behind, and the trigger(s) eliciting these responses, are not. Egregia menziesii (Turn.) Aresch. juveniles (5-10 cm) were incubated for 4 hr in chambers containing {sup 14}C-labeled bicarbonate, under combinations of two levels of nutrient concentration and two levels of tensile force. Whole tissue and cell wall material (=cellulose + alginates) were examined for {sup 14}C incorporation. Tensile force elicited greater incorporation into whole tissue and directed more carbon into the cell wall compartment. Ambient nutrient levels and tissue age both had inverse effects on carbon partitioning into cell wall material. Tensile force also reduced nitrate uptake rates by about 50%.