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Table 1 Regression models predicting percent tree canopy cover, understory green vegetation cover, total char cover, and total fuel loads (Mg ha−1) measured after the 2007 Egley Fire Complex, eastern Oregon, USA, in 2008 and 2016 as a function of one-year post-fire dNBR, time since treatment (Years), and the interaction of one-year post-fire dNBR and time since treatment. Linear regression models were used for 2008 tree canopy cover, 2008 total char, and 2016 understory green vegetation cover and the degrees of freedom were 66 for all models. Beta regression models were used for 2008 understory green vegetation cover, 2016 tree canopy cover, and 2016 total char cover; number of iterations were 34 + 4 (Fisher scoring), 12 + 2, and 23 + 3, respectively. Generalized linear regressions with Gamma family distributions were used for both 2008 and 2016 total fuel loads. Boldface denotes significance at the 95% confidence interval, and SE denotes standard error of the estimate, t = t-statistic (for linear and generalized linear models), z = Z-statistic (given for beta regression models), E = scientific notation (10 to the power of)

From: Short- and long-term effects of ponderosa pine fuel treatments intersected by the Egley Fire Complex, Oregon, USA

 Predictor variables20082016
Tree canopy cover (%) EstimateSEtPEstimateSEzP
dNBR0.0080.0160.4910.625−4.66E−031.23E−03–3.782<0.001
Years0.2450.0623.932<0.0017.70E−034.01E−031.9180.055
dNBR* Years–0.0010.000–2.9440.004−8.90E−061.51E−0.5–0.5890.556
 Model: F = 8.6, P < 0.001, R2 = 0.281Model: z = 6.0, P < 0.001, pseudo R2 = 0.63
Understory green vegetation cover (%) EstimateSEzPEstimateSEtP
dNBR–0.0050.001–4.187<0.0010.0480.0182.657<0.001
Years–0.0070.004–1.7310.084–0.0340.068–0.4910.625
dNBR* Years3.652E-050.0002.3760.018–1.81E-040.000–0.8060.423
 Model: z = 5.5, P < 0.001, pseudo R2 = 0.44Model: F = 5.3, P = 0.003, R2 = 0.193
Total char
cover (%)
 EstimateSEtPEstimateSEzP
dNBR0.0830.0233.635<0.0010.0030.0012.8490.004
Years0.110.0871.2650.2100.0040.0040.9770.328
dNBR* Years–3.65E-040.000–1.2710.208–1.829E-060.000–0.1530.878
 Model: F = 12.1, P < 0.001, R2 = 0.356Model: z = 5.5, P < 0.001, pseudo R2 = 0.26
Total fuel loads (Mg ha–1) EstimateSEtPEstimateSEtP
dNBR9.284E-050.0000.6180.5393.786E-050.0000.9190.362
Years9.186E-060.0000.0220.9821.243E-040.0001.0220.310
dNBR* Years–1.177E-060.000–0.7110.480–8.221E-070.000–1.8240.073
 Null deviance: 82.234 on 68 degrees of freedom,
Residual deviance: 79.626 on 65 degrees of freedom
Null deviance: 33.465 on 69 degrees of freedom,
Residual deviance: 27.429 on 66 degrees of freedom