Are reptile responses to fire shaped by forest type and vegetation structure? Insights from the Mediterranean basin

Socioeconomic factors (e.g. rural abandonment, monoculture plantations) and global warming are changing fire regimes (fire intensity, extent, and frequency) in fire-prone regions such as the Mediterranean Basin. Understanding the factors that shape responses of animal communities to fire is a key objective for biodiversity conservation. Given the substitution of native forests to pine plantations in many regions of the world, we studied whether forest type influences the responses to fire of reptile communities, in the African rim of the Western Mediterranean. Reptiles were sampled and vegetation structure measured in 2015 and 2016. We used generalized linear mixed models to examine the influence of fire, forest type (cork oak and pine), habitat structure and climate factors on two reptile-community metrics (abundance, species richness). Given possible differences in reptile detectability between unburnt and burnt transects, we used distance sampling models to estimate the density of the five commonest reptile species. The response of reptiles to fire varied between the two forest types: reptile abundance did not change with fire in cork oak forest, and increased with fire in pine plantation. Species richness was higher in cork oak forests, and increased from unburnt to burnt areas. Two out of five commonest lizards in the region, Acanthodactylus erythrurus and Podarcis vaucheri, responded positively to fire in pine plantation and remained similar in cork oak forest. Reptile communities were more similar between burnt and unburnt cork oak forests than between burnt and unburnt pine plantations, due to the reduced effect of fire on the former tree (a resprouter species) than on the latter (a seeder species). This work is the first field-based study examining the effects of fire on animal communities from north-western Africa. Overall, our results show that the response of reptiles to fire is shaped by forest type, and this conclusion has to be considered in fire-prone regions.