Fire severity, time since fire, and site-level characteristics influence streamwater chemistry at baseflow conditions in catchments of the Sierra Nevada, California, USA

Santos, Fernanda; Wymore, Adam S.; Jackson, Breeanne K.; Sullivan, S. Mažeika P.; McDowell, William H.; Berhe, Asmeret Asefaw

doi:10.1186/s42408-018-0022-8

Fire Ecology

Table 3 Results from linear (LMM) and generalized linear (GLMM) mixed-effects models with fixed effects (fire severity, time since fire, fire severity × time since fire) and random effects (reach and collection date, not shown) for streamwater chemistry in burned watersheds of Yosemite National Park, California, USA. Streamwater was sampled from the sites between 1 and 13 years after the fire. Marginal (R_m²) and conditional (R_c²) coefficients of determination are shown for variation explained by fixed effects alone, and by both fixed and conditional effects, respectively. N/A means that R² and denominator degrees of freedom (ddf) values are not available for GLMMs, and thus for DOC, NO₃⁻, NH₄⁺, K⁺, Cl⁻, and PO₄³⁻. Bolded P values indicate a significant effect (P < 0.05). F. aliphatics = functionalized aliphatics

From: Fire severity, time since fire, and site-level characteristics influence streamwater chemistry at baseflow conditions in catchments of the Sierra Nevada, California, USA

	Sample size (n)	Fire severity				Time since fire				Fire severity × time since fire				R²
	Sample size (n)	β₁	F	ddf	P	β₁	F	ddf	P	β₁	F	ddf	P	R_m²	R_c²
DOC	94	−2.02	4.78	N/A	0.0006	−0.06	9.64	N/A	0.143	0.23	11.00	N/A	0.004	N/A	N/A
DON	90	−0.03	5.14	79.23	0.026	−0.004	9.03	79.18	<0.0001	0.003	4.56	79.21	0.036	0.14	0.31
TDN	94	−0.02	1.07	7.75	0.332	−0.004	5.18	7.71	0.032	0.002	0.89	7.66	0.375	0.13	0.29
Na⁺	94	−0.16	0.02	8.01	0.879	0.01	0.51	8.01	0.888	0.07	0.28	8.00	0.608	0.71	0.82
Ca²⁺	94	−1.90	0.51	8.00	0.494	−0.10	0.24	8.00	0.673	0.37	1.05	8.00	0.335	0.09	0.90
SO₄²⁺	94	1.30	1.06	7.99	0.333	0.08	0.04	7.99	0.453	−2.20	1.38	7.99	0.274	0.08	0.90
Mg²⁺	94	−0.87	0.48	8.00	0.507	−0.03	0.27	8.00	0.749	0.16	0.86	8.00	0.381	0.07	0.92
Cl⁻	94	0.19	5.25	N/A	0.313	0.03	8.74	N/A	0.036	−0.04	11.57	N/A	0.105	N/A	N/A
NO₃⁻	94	0.52	0.21	N/A	0.294	−0.01	0.96	N/A	0.862	−0.06	0.95	N/A	0.331	N/A	N/A
NH₄⁺	94	−0.09	0.05	N/A	0.842	0.01	0.38	N/A	0.755	0.02	0.11	N/A	0.722	N/A	N/A
K⁺	94	0.12	1.33	N/A	0.883	0.03	1.76	N/A	0.680	0.01	0.05	N/A	0.922	N/A	N/A
PO₄³⁻	94	0.56	3.21	N/A	0.504	0.03	0.38	N/A	0.677	−0.02	0.11	N/A	0.841	N/A	N/A
SUVA₂₅₄	57	−1.39	3.49	9.14	0.094	−0.14	0.09	10.77	0.039	0.25	5.67	8.80	0.042	0.18	0.49
E₂:E₃	57	1.62	6.52	9.13	0.031	0.02	5.39	11.93	0.671	−0.25	8.05	8.63	0.020	0.18	0.44
Arom:Oxy	57	0.04	0.00	9.83	0.957	−0.01	0.11	12.73	0.864	0.05	0.28	9.30	0.608	0.04	0.24
Aromatic	57	−0.27	0.13	9.63	0.722	−0.03	0.01	12.39	0.599	0.07	0.52	9.12	0.490	0.21	0.27
Unsaturated	57	−0.48	0.68	9.87	0.430	−0.03	0.00	12.28	0.505	0.06	0.56	9.41	0.472	0.01	0.44
Oxygenated	57	−4.03	1.00	10.98	0.338	−0.25	0.00	15.48	0.477	0.48	0.72	10.21	0.415	0.019	0.024
F. aliphatics	57	1.40	0.16	53.00	0.694	0.10	0.16	53.00	0.749	−0.39	0.64	53.00	0.426	0.021	0.021
Aliphatics	57	0.74	1.35	10.33	0.272	0.04	0.00	14.59	0.487	−0.07	0.66	9.63	0.435	0.03	0.14

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