Les foréts méditerranéennes problemes posés par leur signification historique, écologique et leur conservation

Acta botánica malacitana, ISSN 0210-9506, Nº 15, 1990, pags. 145-178 01/1990;
Source: OAI

ABSTRACT The mediterranean forest are a naturel milieu, instable and deeply disturbed by man's action. From an historical point of view, their regression can be assessed from the beginning of the Neolithic and especially during the last century. The situation is quite different in the Northern mediterranean countries where, following an intensive land abandonment and in spite of dramatic fires, their surface is generally increasing whereas, in the Southern mediterranean countries, forests are quickly destroyed under combined action of man and cattle. From an ecological point of view, the mediterranean forests constitute very heterogenous units where, according to climatic and edaphic criteris, one can characterize forests, preforests and pre-steppic forests. Their dynamic significance varies essentially according to the types of bioclimate but also according to the species. Their phytosociological significance is nowadays known and a synthesis is attempted. The conservancy of the mediterranean forestsalready presents with serious problems as well for the species, some of them becoming nearly extinct, as for the structures of vegetation. Their protection press the urgency of immediate action. Les forets méditerranéennes représentent un milieu naturel fragile et profondément perturbé par l'action de l'homme. Du point de vue historique, il est utile d'estimer dans la mesure du possible, la regression qu'elles ont subie depuis le début du Néolithique, et tout spécialement au cours du dernier siècle. La situation est totalement différente dans les pays du revers septentrional oil á la suite dune intense déprise rurale et malgré de dramatiques incendies, leur superficie tend globalement á s'accroitre, alors que dans les pays du revers sud, on assiste a une destruction accélérée du capital forestier sous faction conjuguée de l'homme et de ses troupeaux. Du point de vue écologique, les foréts méditerranéennes constituent des ensembles tres hétérogenes, oil, en fonction des criteres climatiques et aussi édaphiques, Ion est amené á distinguer des structures franchement forestieres, des préforéts et des forks pré-steppiques, dont la signification dynamique vane essentiellement suivant les types de bioclimat, mais aussi des essences constitutives. Leur signification phycosociologique est actuellement assez bien connue et un essai de synthese est tente ici. Du point de vue de leur conservation, de dramatiques problémes se posent dés á present aussi bien au niveau des essences, dont certaines se trouvent en situation naturelle proche de l'extinction, que des structures de vegetation. Des solutions d'urgence devront étre trouvées dans les plus brefs délais, pour assurer leur sauvegarde

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