Table 1.

Coefficients, 95% confidence intervals (CI) and coefficients of determination (R²) of quadratic regression models of species richness versus frequency and species richness versus biovolume in the three habitats. (N, number of data points; AVG, average; MAX, maximum; p<0.000005 for all relationships.)

habitat	log2 (frequency)	log2 (biovolume)	AVG log2 (biovolume)	MAX log2 (biovolume)
DTH
N	98	1700	98	98
R2	0.82	0.05	0.37	0.65
b0	−0.69	25.81	25.72	25.32
95% CI	−1.20 to −0.18	24.89–26.74	24.68–26.77	23.96–26.68
b1	0.22	0.15	0.16	0.39
95% CI	0.19–0.24	0.11–0.18	0.12–0.21	0.33–0.45
b2	−0.0021	−0.0012	−0.0014	−0.0035
95% CI	−0.0023 to −0.0019	−0.0015 to −0.0008	−0.0018 to −0.0010	−0.0041 to −0.0030
u	52	63	59	55
t	15	21	19	12
RTH
N	93	2730	93	93
R2	0.91	0.04	0.45	0.69
b0	2.07	24.94	24.83	28.97
95% CI	1.74–2.40	24.35–25.54	24.09–25.57	27.96–29.98
b1	0.18	0.15	0.15	0.31
95% CI	0.16–0.20	0.12–0.18	0.08–0.13	0.26–0.36
b2	−0.0022	−0.0015	−0.0014	−0.0035
95% CI	−0.0023 to −0.0020	−0.0018 to −0.0012	−0.0018 to −0.0010	−0.0040 to −0.0030
u	41	50	53	45
t	15	18	19	12
phytoplankton
N	86	468	86	86
R2	0.57	0.15	0.49	0.29
b0	1.44	11.10	11.61	20.49
95% CI	0.58–2.31	8.97–13.23	9.57–13.67	16.35–24.63
b1	0.70	3.56	3.11	2.61
95% CI	0.39–1.01	2.73–4.39	2.38–3.84	1.12–4.10
b2	−0.0825	−0.2916	−0.2365	−0.2745
95% CI	−0.1086 to −0.0564	−0.3666 to −0.2166	−0.2979 to −0.1751	−0.3997 to −0.1494
u	4.24	6.10	6.57	4.75
t	2.46	1.31	1.45	1.35
u2	18	37	43	23