Table 2. Output of a logistic regression model (binomial family, logit link function) investigating the effects of fire severity, pre-fire size and site on post-fire thicket shrub survival.

Effects include fire severity scored at the base of each shrub (Firebase; orthogonal polynomial contrast trend test; L, linear; Q, quadratic; C, cubic), pre-fire size (Prefiresize; see Methods for details), site and fire severity × pre-fire size interaction. Models were fitted using treatment contrast with Cape St. Francis as the reference level for site comparison with Knysna (KNS).

Survival	Regression coefficients are log odds, standard errors in brackets
(Intercept)	1.28 (0.23)***
Firebase.L	0.23 (0.46)
Firebase.Q	0.66 (0.38)
Firebase.C	0.88 (0.27)**
Prefiresize	2.52 (0.68)***
SiteKNS	−0.37 (0.17)*
Firebase.L:Prefiresize	−2.98 (1.68)
Firebase.Q:Prefiresize	−0.58 (1.36)
Firebase.C:Prefiresize	−2.08 (0.94)*
Number of observations	1,398
Nagelkerke R2	0.05

Notes:

^*p < 0.05.

^**p < 0.01.

^***p < 0.001.