Effect of spring grass fires on vegetation patterns and soil quality in abandoned agricultural lands at local and landscape scales in Central European Russia

Ecological Processes

Table 2 Statistically significant results of the logistic regression model of fire occurrences

Predictor	Estimate	Std. error	Wald z value	P	Odds ratio	95% CI for odds ratio
Intercept	− 5.925	0.478	− 12.937	< 0.001	0.003	0.001–0.007
Continuous
Polygon area, log₂	0.190	0.027	7.098	< 0.001	1.209	1.152–1.276
Ratio of the number of burnt neighboring polygons to the number of total neighboring polygons, %	0.027	0.002	16.790	< 0.001	1.027	1.024–1.030
Categorical
Presence of settlements (1/0)	0.198	0.090	2.207	0.027	1.219	1.023–1.454
Al2	1.402	0.180	7.847	< 0.001	4.063	2.875–5.795
Al3	2.080	0.177	11.744	< 0.001	8.005	5.686–11.393
Al4	2.836	0.163	17.375	< 0.001	17.054	12.456–23.636
Arable lands	3.452	0.228	15.138	< 0.001	31.555	20.386–49.885
Meadows	2.249	0.181	12.432	< 0.001	9.475	6.681–13.585
Sparse forests	1.903	0.339	5.610	< 0.001	6.707	3.467–13.173

McFadden’s pseudo R² = 0.217. le Cessie-van Houwelingen-Copas-Hosmer global goodness-of-fit test: z = 1.5387, P value = 0.1239
Al2, Al3, and Al4 are abandoned lands which differ in coverage of woody vegetation: Al2 with a dense tree cover in spots, Al3 with a tree cover of small density, and Al4 without trees or with a few single trees