Collapse of an iconic conifer: long-term changes in the demography of Widdringtonia cedarbergensis using repeat photography

Table 1 Fitted coefficients, the standard errors, P values of the generalized linear mixed-model for probability of W. cedarbergensis mortality across all regions (model 1) and in natural stands (model 3), probability of recruitment across all regions (model 2) and the Wald test of fixed effects

Predictors	Model 1		Model 2		Model 3
Predictors	Estimate	S.E.	Estimate	S.E.	Estimate	S.E.
(a)
Intercept	–9.14*	2.85	9.23	5.72	–9.96*	4.40
Habitat-open	0.39	0.45	1.19	0.76	0.41	0.61
Habitat-rocky	0.26	0.23	0.38	0.50	0.55*	0.27
Aspect-north	1.45***	0.41	0.00	0.82	1.99***	0.45
Aspect-south	0.49	0.30	0.15	0.69	1.24***	0.34
Aspect-west	0.89**	0.33	0.78	0.63	1.43***	0.41
Fire frequency	0.09	0.12	–0.18	0.23	0.30*	0.14
MAT	0.70**	0.23	–0.96*	0.47	0.64	0.36
Random effects (R.E.)	0.00	0.97	0.00	0.98	1.02	0.90

Predictors	Χ²	p value	Χ²	p value	Χ²	p value
(b)
Habitat	18.6	0.000	2.5	0.290	9.0	0.029
Aspect	18.8	0.000	8.7	0.068	26.9	0.000
Fire frequency	0.5	0.468	0.6	0.440	4.6	0.033
MAT	9.6	0.002	4.2	0.041	3.2	0.073

R.E.: n_region = 4; n_site = 86, R.E.: n_region = 4; n_site = 86, R.E.: n_region = 3, n_site = 80, n_tree = 1313, n_tree = 1357, n_tree = 821
Habitat well protected and aspect–east set as intercept, MAT Mean annual temperature
p values: 1 < 0.10, * < 0.05, ** < 0.01, *** < 0.001

ISSN: 1472-6785