Table 1.
Growth rate, stoichiometry and photosynthetic parameters for Chaetoceros wighamii under different growing conditions.
Fig 1.
The growth rate during exponential growth of Chaetoceros wighamii acclimated to different irradiance and temperature.
The response surface represents the model fit to the data in Table 1, and a statistical comparison with a fitted plane is presented in Table 2. Dots represent the different combinations of light and temperature.
Table 2.
The coefficient of multiple determination (R2) for a fitted plane and the modeled response surface with a statistical test of differences between these two ways of representing the data.
Fig 2.
The stoichiometric relationships: C:N (molar ratio), C:P (molar ratio), N:P (molar ratio) and C:Chl a (weight ratio) during exponential growth of Chaetoceros wighamii acclimated to different irradiance and temperature.
The data is presented in Table 1, and a statistical comparison with a fitted plane is presented in Table 2.
Fig 3.
The stoichiometric relationships: C:N (molar ratio), C:P (molar ratio), N:P (molar ratio) and C:Chl a (weight ratio) during exponential growth of Chaetoceros wighamii acclimated to different temperature.
The culture was acclimated to four irradiance levels for each temperature (20, 40, 130 and 450 μmol photons m-2 s-1). The horizontal line is the median, the box represents the 25–75% confidence interval, and the error bars the 10–90% confidence interval (n = 4). There were no statistical difference between means, but there was an effect of temperature on the variance (see text for details). The data can be found in Table 1.
Fig 4.
The stoichiometric relationships: C:N (molar ratio), C:P (molar ratio), N:P (molar ratio) and C:Chl a (weight ratio) of Chaetoceros wighamii during different nutrient limitation and combination of growth light and temperature (details and data can be found in Table 1).
The horizontal line is the median, the box represents the 25–75% confidence interval, and the error bars the 10–90% confidence interval (n = 5). Statistical comparisons between the nutrient limitations are presented in Table 3.
Table 3.
ANOVA table comparing the effect of nutrient limitations (N, P or Si) on stoichiometric ratios (Fig 4) with Tukey’s Post Hoc test for pairwise comparison.
Fig 5.
The maximum light utilization coefficient (α*) in mol O2 (mg Chl a)-1 h-1 (mol photons m-2 s-1)-1, photosynthetic maximum (Pm*) in μmol O2 (mg Chl a)-1 h-1, light compensation point (Ec) in μmol photons m-2 s-1 and light saturation parameter (Ek) in μmol photons m-2 s-1 during exponential growth of Chaetoceros wighamii acclimated to different irradiance and temperature.
The data is presented in Table 1, and a statistical comparison with a fitted plane is presented in Table 2.
Fig 6.
The photosynthetic quotient (PQ; mol O2 produced per mol C fixed) at exponential and stationary growth phases (both N and P limited), and at the initial slope (α*) and photosynthetic maximum (Pm*) of the PE curve.
The horizontal line is the median, the box represents the 25–75% confidence interval, and the error bars the 10–90% confidence interval (n = 12 for exponential growth; n = 5 for N and P limitation). The data is presented in Table 1.