Tree Mortality following Prescribed Fire and a Storm Surge Event in Slash Pine (Pinus elliottii var. densa) Forests in the Florida Keys, USA

Table 4

1- and 7-year post-fire tree mortality models for slash pine after prescribed burns carried out between 1998 and 2001 in Big Pine Key, Florida.

Models	𝑛	Variables			Coefficients				H-L (𝜒^2)	P	C
		𝑋1	𝑋2	𝑋3	𝛽0	ß1	ß2	ß3
1-year post fire
1	3523	DBH	CH	CVS	−5.8901	−0.1166	0.5379	0.0546	292.2	.001	0.911
					(0.4041)	(0.0133)	(0.0407)	(0.0041)
2	3530	DBH	CH	—	−1.2808	−0.2105	0.9168		157.6	.001	0.845
					(0.1212)	(0.0129)	(0.0396)
3	3550	CVS	—	—	−7.2966	0.0720			444.8	.001	0.888
					(0.4162)	(0.0044)
7-year post fire
4	2227	DBH	CH	CVS	−1.1753	−0.1109	0.3974	0.0171	36.1	.001	0.768
					(0.1890)	(0.0117)	(0.0363)	(0.0018)

n: number of trees observed.
Standard error of constant and independent variable coefficients are given in the parenthesis with each coefficient value.
DBH: Diameter at breast height (cm); CH: Char height (m); CVS: Percent crown scorch (%).
H-L (𝜒²): Hosmer and Lemeshow chi-square statistic for assessing goodness of fit.
P: Statistical significance of Hosmer and Lemeshow (𝜒²) test statistic.
𝐶: Concordance value which is equivalent to area under the curve in the receiver operations characteristic (ROC) curve analysis for assessing the performance of the model.