Le chêne zéen (Quercus canariensis Willd.) en Tunisie: Écologie, production, état de dégradation et les pratiques d’aménagement

This study is a review paper of species Quercus canariensis, an endemic species of the Ibero-Maghreb localities (Spain, Portugal, Morocco, Algeria, Tunisia). This work will contribute firstly to knowledge of the ecology and production of this species which has undergone a lot of pressure and degradation in recent years in Tunisia and secondly the prospects for the management practices of the species for their protection. This study is carried out with the aim of studying the ecology, production and state of degradation of the species and finally to study the management practices of Quercus canariensis in Tunisia. It is based on research work carried out in Tunisia over 70 years on Quercus canariensis (30 bibliographical references since 1952). In Tunisia, the main zeen oak stands are concentrated in the mountains of Western Kroumirie. The first clear cuts of zeen oak in Tunisia were made between 1883 and 1895 in El Feidja and Ain Draham. Before colonization, the zen oak occupied 100,000 ha in the north-west of Tunisia. In 1970 this area decreased to 40,000 ha, including 10,000 ha in pure stands and 30,000 ha mixed with cork oak. Currently the area of ??zeen oak is estimated at 8,332 ha in pure stand and 13,651 ha mixed with cork oak. The ancient zeen oak trees exceed an age of 330 years. The mean annual growth of zeen oak stands varies between 4 and 8 m3 ha-1yr-1 in middle-aged stands. In this stand, the standing volume is 307.8 m3 ha-1. Total biomass production varies between 211 and 267 Mg ha-1. The zeen oak forest has lost, after 40 years, about 40% of its area. However, new forest species have occupied the landscape since the end of the 1980s, such as the acacia, the Aleppo pine, the eucalyptus, the stone pine and the maritime pine which are now invading the zeen oak ecosystem and oak cork. Today, the zeen oak forest faces continuous progressive and irreversible degradation. Deforestation has prevented natural regeneration, moreover, various diseases and climate change also play a negative role. So we add to this set of factors the absence of forest management, hence silvicultural treatments are necessary for the conservation and enhancement of this noble species which is considered a natural heritage in Tunisia. Keywords: Zeen oak, Geographical distribution, Increase, Production, Silviculture, Management, Interest