Le cèdre, essai d’interprétation bioclimatique et écophysiologique

Abstract

Cedrus species occupie a limited area in the mountain stage of the mediterranean region and in the Himalayian Mountains. In a certain way this area does not appear totally in relation with the real ecological fitness in this species. In connection with the problems set by the forestry of this species, great strides have been made in order to know more about its ecophysiology. These species can endure very strong winter weather without being damaged, but all other characteristics that have been analysed, show that their ecology corresponds to mild weather. They also seem able to use beneficially irregular rainfalls during the year thanks to their type of height growth and their capacities of photosynthesis during the drought. But the blockage of their transpiration, that happens extremely late, could lead species into difficult conditions, mainly when drought is prolonged during several months. The available data make us thinking that Cedrus atlantica and Cedrus libani could be considered as species that can exist in transition climate, that is, between a cold climate, and hot and dry climate. Their optimum conditions for growth would be in regions that have cool winter (active winter photosynthesis) and dry summer. Considering this ecophysiological and bioclimatic interpretation, the author thinks that it is possible to extend Cedrus sp. to countries which have a transition climate. Ó 1993 Taylor & Francis Group, LLC. © 1984 Taylor & Francis Group, LLC.