Portugal has the highest density of wildfire ignitions among southern European countries. The ability to predict the spatial patterns of ignitions constitutes an important tool for managers, helping to improve the effectiveness of fire prevention, detection and firefighting resources allocation. In this study, we analyzed 127 490 ignitions that occurred in Portugal during a 5-year period. We used logistic regression models to predict the likelihood of ignition occurrence, using a set of potentially explanatory variables, and produced an ignition risk map for the Portuguese mainland. Results show that population density, human accessibility, land cover and elevation are important determinants of spatial distribution of fire ignitions. In this paper, we demonstrate that it is possible to predict the spatial patterns of ignitions at the national level with good accuracy and using a small number of easily obtainable variables, which can be useful in decision-making for wildfire management.

In the Iberian Peninsula Mediterranean oak forests have been transformed into a mosaic landscape of four main patch-types: forests, savannas, shrublands and grasslands. We used aerial photographs over a period of 45 years (1958–2002) to quantify the persistence and rates of transitions between vegetation patch-types in southern Portugal, where cork oak is the dominant tree species. We used logistic regression to relate vegetation changes with topographical features and wildfire history. Over the 45 years, shrublands have been the most persistent patch-type (59%), and have been expanding; forests are also persistent (55%) but have been decreasing since 1985; savannas and grasslands were less persistent (33% and 15%, respectively). Shrublands persistence was significantly correlated with wildfire occurrence, particularly on southern exposures after 1995. In contrast, forest persistence decreased with wildfire occurrence, and forests were more likely to change into shrublands where wildfire had occurred after 1995.