A systematic review on the endemic Moroccan fir (Abies marocana Trab.) and its implications for conservation and future research perspectives

Moroccan fir, known botanically as Abies marocana Trab. (Pinaceae), is a North African mountain coniferous species endemic to the calcareous ridge of the western Rif Mountains (northern Morocco). It is adapted to humid and perhumid bioclimates. It is one of the circum-Mediterranean firs of the section Piceaster, characterized by rigid needles. The species is endangered and included on the IUCN Red List of Threatened Species. This relict species plays key ecological roles in maintaining genetic, specific and ecosystemic biodiversity. Little attention has been devoted to A. marocana forest regeneration, which is one of the biggest concerns for scientists and managers. The present review critically synthesizes the available peer-reviewed literature on A. marocana to highlight the scientific advances on this species and to address knowledge gaps that may constitute future research perspectives. The factors threatening the existence of A. marocana forests the most are anthropogenic pressure, mainly agricultural expansion (especially the cultivation of Cannabis), which is reported to be the main cause of the continuous decline in the range of the species, and climate change. We have identified several knowledge gaps, mainly in species ecophysiology, climate change impacts, pests and diseases, seed germination and regeneration requirements, restoration, biological properties of essential oils and organic extracts, and ex situ conservation. Suitable strategies for both in situ and ex situ conservation of the species should be an urgent topic for both scientists and foresters.