Interactions of fire and forest structure in a relict mesic forest of north Africa

Abstract

Background Site-specific data about fire regimes and ecosystem attributes is valuable for developing conservation strategies. Aims We determined fire history linked to forest attributes in Talassemtane National Park, Morocco, which conserves rare species at the northern tip of Africa. Methods We sampled fire-scarred conifers at three high-elevation forest sites, along with forest measurements. Key results Surface fires recurred frequently at all sites (mean fire intervals 15–23 years) over the period 1879–2018, burning primarily in the late summer. Fires were not highly synchronous among sites and were not climate-driven, suggesting a pattern of human ignitions at times when burning was safe. Stands were dominated by large and old Pinus and Abies trees that had survived numerous surface fires. Sites where fires continued to the present had relatively open structure with few ladder fuels. The site where 36 years had passed since the last fire had a dense mid-storey of sprouting Quercus trees. Conclusions Fire regimes and forest attributes were linked with fire-quiescent periods associated with high tree density, creating ladder fuels that could support crown fire. Implications Maintaining frequent-fire regimes in these forests could provide benefits for reducing fuels, avoiding undesired fires under extreme conditions, and supporting adaptation to warmer climate.