Resilience of bird communities after wildfires in Algerian cork oak forests

Wildfire recurrence is a threat to North African forest ecosystems. The objective of this study is to assess the impact of fire on the avifauna of Algerian cork oak forests and evaluate their resilience in a conservation perspective. We adopted both synchronic sampling (selection of sites supposed representative of successional stages) and diachronic sampling (sampling of the same sites repeated over time) of the avifauna of cork oak stands situated in a fire-prone area of NE Algeria. Using multivariate analyses, we measured the degree of fire alteration of these ecosystems, reconstituted a post-fire successional series, tracked the post-fire recovery, and analyzed the response of each bird species. The results show that the number of species decreases after fire and then increases until it reaches a plateau at around 20-30 years of age. The responses of bird species to fire are relatively similar to those north of the Mediterranean (France, Spain) with few exceptions, in particular because the relatively early sampling includes some late winterers. After the disappearance of the forest species (e.g. Regulus ignicapilla, and Coccothraustes coccothraustes) and the appearance of a few open-habitat species immediately after the fire (e.g. Galerida cristata, Oenanthe hispanica), the former recolonise and the composition of the avifauna stabilises after around twenty years after fire. Even subjected to repeated fires, these forests seem to have the ability to regenerate and recover their pre-fire avifauna and vegetation structure within about 30 years. Despite the apparent resilience shown by these cork forests in the short-term, we do not know the consequences on strictly forest birds of an increase in fire frequency resulting from an increased human pressure and climate change, and recommend protection of these ecosystems to ensure their sustainability.