Fire Ecology

Table 1 Response of fire behavior, weather, and fuel variables to fire season (fixed effects), plot, and year (crossed random effects)

From: Season affects fire behavior in annually burned humid savanna of West Africa

Variables	Fixed effects				Random effects
	Fire season (n = 3)				Plot (n = 9)		Year (n = 4)
	F	df	P value	R²	χ² (1 df)	P value	χ² (1 df)	P value
Fire intensity^a	7.17	2.33	0.003	0.30	0.00	1.000	2.27	0.132
Flame height	16.17	2.33	< 0.001	0.49	0.01	0.925	1.83	0.176
Rate of fire spread^a	11.78	2.33	< 0.001	0.42	0.01	0.912	1.57	0.210
Residence time > 60 °C	4.53	2. 24	0.021	0.27	0.00	1.000	1.34	0.247
Maximum temperature	6.67	2.24	0.005	0.36	0.00	1.000	0.58	0.447
Combustion efficiency	9.24	2.6	0.015		4.49	0.034	0.00	1.000
Wind speed	3.97	2.6	0.029		0.00	1.000	35.59	< 0.001
Air temperature	2.35	2.33	0.112	0.12	0.01	0.921	0.14	0.706
Air humidity	3.55	2.33	0.040	0.18	0.00	1.000	2.83	0.093
Fuel load (fresh)	23.14	2.30	< 0.001		0.00	1.000	10.95	< 0.001
Fuel moisture content	11.16	2.33	< 0.001	0.40	0.00	1.000	0.11	0.738
Grass height	58.41	2.30	< 0.001		0.00	1.000	15.01	< 0.001

Mixed models analyses were performed with the R lmer function. R² values provided for fixed-effects models when random effects were not significant. Boldface data indicates effects significant at the 0.05 level. F = F value; df = degrees of freedom; χ² = chi-squared statistic
^alog-transformed prior to analysis based on the distribution of residuals.

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