TABLE 2.

Univariate models predicting bacterioplankton alpha diversity as a function of various environmental characteristics in freshwater lakes^a

Characteristic	OTU richness			Pielou's evenness			Faith's PD			SES.PD			MNTD			SES.MNTD
	Model type	AIC value	R2	Model type	AIC value	R2	Model type	AIC value	R2	Model type	AIC value	R2	Model type	AIC value	R2	Model type	AIC value	R2
pH	Quadratic	290	0.78	Quadratic	−93	0.79	Quadratic	169	0.74	Linear	108	0.66	Quadratic	−130	0.86	Linear	103	0.64
TOC (mg · liter−1)	Quadratic	313	0.43	Quadratic	−62	0.28	Quadratic	191	0.39	Quadratic	131	0.21	Quadratic	−92	0.34	Quadratic	125	0.20
TFe (mg · liter−1)	Linear	325	0.01	Linear	−56	0.02	Linear	200	0.06	Quadratic	129	0.29	Quadratic	−86	0.15	Quadratic	124	0.26
Area (km2)	Linear	323	0.08	Linear	−58	0.08	Linear	200	0.06	Linear	133	0.08	Linear	−86	0.06	Linear	128	0.05
NOx− (mg · liter−1)	Linear	325	0.01	Quadratic	−57	0.14	Quadratic	199	0.17		135	0.01	Quadratic	−87	0.18		128	0.03
TP (mg · liter−1)	Linear	325	0.02	Linear	−57	0.04	Linear	201	0.01	Quadratic	133	0.12	Quadratic	−85	0.12	Quadratic	128	0.12
Conductivity (μS · cm−1)	Linear	325	0.01	Linear	−56	0.01	Linear	202	0.01	Linear	134	0.05	Linear	−85	0.04	Linear	128	0.05
TN (mg · liter−1)	Linear	324	0.03	Linear	−56	0.02	Linear	201	0.01	Linear	135	0.02	Linear	−85	0.02	Linear	129	0.02

^aIn each case, we fitted a linear and a quadratic model; results are shown for the model with the lowest AIC value. Lower AIC values indicate stronger support for the model, balancing model fit and parsimony.