Are fire temperatures and residence times good predictors of survival and regrowth for resprouters in Florida, USA, scrub?

Fire Ecology

Table 4 Linear mixed effects model predicting change in relative growth rates (RGR) from pre-fire heights to one-year post-fire heights (n = 287) following 13 prescribed fires, from 2006 to 2010, at Archbold Biological Station, Venus, Florida, USA, where the effect of prescribed fire on resprouting Florida vegetation was examined. Plants within transects were not independent so transect was evaluated as a random effect (variance = 0.011) in the model. Variables included maximum fire temperature, residence time in seconds (log), burn season, habitat, species group, and two-way interactions. Reference categories for burn season were “Fire”, “Scrubby Flatwoods” for habitat, and “Oaks” for species groups. The burn season * habitat interaction was not included due to low or missing cells. For each variable, the estimated coefficient (β ± standard error [SE]) shows the relationship and magnitude of change with relative growth. Sample size (n) is provided for each group and the mean first-year relative growth rate (RGR). Significant effects (P < 0.05) are highlighted in bold and marginal predictors are in italics (P < 0.1). The random effects of transect were also not significant (P < 0.001)

Fixed effects		β (SE)	P-value	R²	n	First year RGR
Intercept		−0.70 (0.370)	0.062	0.254		−0.410
Maximum temperature		<0.01 (<0.001)	0.107	0.009	287
Residence time (log)		0.11 (0.128)	0.401	0.003	287
Burn season	Fire				148	−0.457
	Wet	0.32 (0.211)	0.146	0.010	78	−0.291
	Dry	0.14 (0.241)	0.557	0.002	61	−0.516
Habitat	Scrubby flatwoods				130	−0.372
	Sandhill	−0.15 (0.209)	0.486	0.002	68	−0.527
	Sand pine–oak scrub	−0.43 (0.244)	0.105	0.014	30	−0.384
	Flatwoods	−0.37 (0.244)	0.130	0.009	59	−0.441
Species groups	Oaks				90	−0.535
	Palms	0.43 (0.291)	0.140	0.007	47	−0.113
	Ericads	0.25 (0.245)	0.316	0.004	61	−0.654
	Graminoids	0.46 (0.625)	0.463	0.002	27	0.250
	Shrubs	−0.25 (0.305)	0.415	0.002	62	−0.567
Sandhill*Palms		0.21 (0.310)	0.509	0.001
Sand pine–oak scrub*Palms		0.50 (0.397)	0.205	0.005
Flatwoods*Palms		0.33 (0.353)	0.370	0.003
Sandhill*Ericads		−0.17 (0.328)	0.596	0.001
Sand pine–oak scrub*Ericads		0.81 (0.498)	0.103	0.009
Flatwoods*Ericads		0.42 (0.302)	0.166	0.007
Sandhill*Graminoids		−0.78 (0.502)	0.122	0.008
Sand pine–oak scrub*Graminoids		−0.16 (0.526)	0.760	<0.001
Flatwoods*Graminoids		−0.34 (0.445)	0.445	0.002
Sandhill*Shrubs		0.06 (0.293)	0.839	<0.001
Sand pine–oak scrub*Shrubs		0.27 (0.427)	0.524	0.001
Flatwoods*Shrubs		0.41 (0.297)	0.166	0.007
Wet*Palms		−0.33 (0.309)	0.284	0.004
Dry*Palms		−0.03 (0.340)	0.952	<0.001
*WetEricads**		−0.84 (0.292)	0.004	0.029
Dry*Ericads		−0.29 (0.314)	0.355	0.003
Wet*Graminoids		0.72 (0.752)	0.342	0.003
Dry*Graminoids		0.97 (0.708)	0.173	0.006
Wet*Shrubs		−0.01 (0.303)	0.965	<0.001
Dry*Shrubs		0.35 (0.376)	0.357	0.003