Mapping the Fundamental Niches of Two Freshwater Microalgae, Chlorella vulgaris (Trebouxiophyceae) and Peridinium cinctum (Dinophyceae), in 5-Dimensional Ion Space

Table 1

ANOVA P-values, regression coefficients and model fit diagnostics for Chlorella vulgaris specific growth rate, μ (d⁻¹), and relative cell density (percent of maximum) for combined, cubic x quadratic Scheffé polynomial models. Only third order or lower terms significant at 𝑃<0.05 for at least one response are presented. Note that the single component P-values (i.e., NO₃, PO₄, etc.) are covered under “Linear Mixture”. The data were transformed with an inverse square root function before analysis; thus, regression coefficients with lesser values indicate greater effects. C.V.: coefficient of variance, n/s: 𝑃>0.05.

	Specific growth rate		Relative cell density
	Regression		Regression
Source	Coefficients	P-values	Coefficients	P-values
Model		<0.0001		<0.0001
Linear mixture		<0.0001		<0.0001
NO3	10.3		9.9
PO4	10.4		10.0
K	1.9		2.0
Na	2.0		2.4
Cl	10.3		9.8
K * Cl	7.2	0.0001	6.7	0.0002
K * [Conc]		n/s	−1.7	0.0005
Na * [Conc]		n/s	−1.4	0.0052
NO3 * PO4 * K	74.0	<0.0001	73.9	<0.0001
NO3 * PO4 * Na	84.6	<0.0001	83.9	<0.0001
NO3 * K * Na	−74.0	<0.0001	−87.6	<0.0001
NO3 * K * Cl	53.9	<0.0001	55.0	<0.0001
NO3 * Na * Cl	79.6	<0.0001	74.8	<0.0001
PO4 * K * Na	−59.5	<0.0001	−68.4	<0.0001
PO4 * K * Cl	60.3	<0.0001	59.1	<0.0001
PO4 * K * [Conc]	6.0	0.0086	6.9	0.0015
PO4 * Na * Cl	85.8	<0.0001	79.4	<0.0001
K * Na * Cl	−79.6	<0.0001	−81.5	<0.0001
Na * Cl * [Conc]	8.4	0.0006	8.5	0.0002
NO3 * K * (NO3-K)	38.4	<0.0001	39.1	<0.0001
NO3 * Na * (NO3-Na)	39.5	<0.0001	39.2	<0.0001
PO4 * K * (PO4-K)	36.4	<0.0001	37.8	<0.0001
PO4 * Na * (PO4-Na)	37.9	<0.0001	38.5	<0.0001
K * Cl * (K-Cl)	−44.4	<0.0001	−40.2	<0.0001
Na * Cl * (Na-Cl)	−28.5	<0.0001	−27.1	<0.0001
Lack of Fit		<0.0001		<0.0001
Std. Dev.:		1.06		1.00
Mean:		7.54		7.22
C.V.%:		14.12		13.89
𝑅^2:		0.95		0.95
𝑅^2-adj:		0.93		0.93
𝑅^2-pred:		0.88		0.89