Fig. 3From: The short-term effects of elevated CO2 and ammonium concentrations on physiological responses in Gracilariopsis lemaneiformis (Rhodophyta)Rates of photosynthetic oxygen evolution (μmol O2 g−1 FW h−1) of Gracilariopsis lemaneiformis at different pH and NH4 + treatments. Bars not labeled with same letter indicate significant differences among culture conditions at p < 0.05. Values are means ± SD (n = 4)Back to article page