Figure 1.
Microprofiles of oxygen around Potamogeton malaianus stems and leaves with and without periphyton.
A, C, and E indicate thick periphyton; B, D, and F indicate periphyton removed; G indicates young leaves with little periphyton. Microprofiles were measured at three different points under quantum flux density of 300 µmol photons·m–2·s–1 on P. malaianus stems and leaves. The outer surfaces of the periphyton layer are indicated by horizontal bars. The leaf surfaces are indicated by 0. Microprofiles of oxygen around young leaves were not markedly different between the presence of little periphyton and periphyton removed.
Figure 2.
Schematic of oxygen microprofiles around submerged macrophyte leaves with periphyton.
Table 1.
The characteristics of periphyton on the leaves and stems of Potamogeton malaianus.
Table 2.
The estimated O2 fluxes (μmol·cm–2·min–1) through the broad diffusive boundary layer associated to the surface of Potamogeton malaianus according to Fick's first law (n = 3)
Figure 3.
Microprofiles of pH around Potamogeton malaianus stems and leaves with and without periphyton.
A, C, and E, indicate thick periphyton; B, D, and F indicate periphyton removed; G indicates young leaves with a little periphyton. Microprofiles were measured at three different points under quantum flux density of 300 µmol photons·m–2·s–1 on P. malaianus stems and leaves. The outer surfaces of the periphyton layer are indicated by horizontal bars. The leaf surfaces are indicated by 0. The microprofiles of pH around young leaves were not markedly different between the presence of little periphyton and periphyton removed.
Figure 4.
Microprofiles of oxidation-reduction potential around Potamogeton malaianus stems and leaves with and without periphyton.
A, C, and E, indicate thick periphyton; B, D, and F indicate periphyton removed; G indicates young leaves with little periphyton. Microprofiles were measured at three different points under quantum flux density of 300 µmol photons·m–2·s–1 on P. malaianus stems and leaves. The outer surfaces of the periphyton layer are indicated by horizontal bars. The leaf surfaces are indicated by 0. Microprofiles of oxidation-reduction potential around young leaves were not markedly different between the presence of little periphyton and periphyton removed.
Figure 5.
Microprofiles of oxygen, pH, and oxidation-reduction potential around the same Potamogeton malaianus stem and leaf.
A, C, and E indicate thick periphyton; B, D, and F indicate periphyton removed. Microprofiles were measured under quantum flux density of 300 µmol photons·m–2·s–1 on P. malaianus stems and leaves. Values with bars indicate standard deviations (n = 3).
Figure 6.
Rapid light curves of Potamogeton malaianus with different biomass densities of periphyton.
Values with bars indicate standard deviations, n = 3.