Skip to main content

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 (Rm2) and conditional (Rc2) 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
β1 F ddf P β1 F ddf P β1 F ddf P Rm2 Rc2
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