Table 2.

In situ minimum and maximum O₂ partial pressures (pO₂) in leaf lacunae of I. australis, vegetated sediments, and overlying water column

	Component
	Leaf lacunae (kPa)	Sediment (kPa)	Water column (kPa)
Minimum pO2 (mean ±SE) n=3	1.6±0.7a	2.3±0.4a	11.3±1.0b
Maximum pO2 (mean ±SE) n=6	30.9 ±1.1a	32.9 ±2.0a	21.3±1.5b

O₂ microelectrodes were inserted into a leaf lacuna of a fully expanded leaf, into the sediment (10 mm depth), and at canopy height in the water column. Measurements in non-vegetated sediments always showed values below the detection limit (<0.1 kPa). Letters indicate significant differences (ANOVA and Tukey post hoc; P<0.05) and n=3 minimum dark values or 6 for maximum day values as maximum values from the first and second days were included.