Predicting potential distribution area of thuriferous juniper (Juniperus thurifera) in Morocco

Conservation and good management of endangered forest species require knowledge of their potential spatial distribution and the environmental factors defining this distribution. The present paper deals with the identification of environmental factors controlling the spatial distribution of thuriferous juniper (Juniperus thurifera L. ssp. africana (Maire) Gauquelin & al.) in Morocco and the mapping of its potential distribution under current climatic conditions. The Maximum Entropy algorithm was used in this assessment. The adjusted model had an excellent predictive quality (AUC = 0.938). Environmental parameters that preclude the spatial distribution of thuriferous juniper are the minimum temperature of the coldest month, temperature seasonality and altitude. The potential area mapped showed that large parts of the Atlas Mountains are suitable to the expansion of Juniperus thurifera stands. Further, current species distribution represents only 5% of its suitable area. These findings will help decision makers and forest planners to better identify suitable sites to rehabilitate this vulnerable species, whose area is declining.

Keywords: Morocco, thuriferous juniper, maximum entropy, MaxEnt, species distribution, modeling, bioclimatic variables