The Algerian forest in its totality covers about 4.1 mill. hectares. Confined to the humid, subhumid, semi-arid and and bioclimatic stages, it accounts for only 11% of the northern part of the country (tellian and steppic areas) where the productive forest occupies 124 900 hectares. In this unit, the cork oak and pine forest with Pinus halepensis occupy the majority of the forested areas. Over the last decades, the effects of drought combined with a demographic explosion and the lack of traditions in forest management and silviculture are the principal causes of forest degradation. Repeated fires, pest and diseases and illegal cuttings caused huge losses to this patrimony, already weakened by the supposed effects of climatic changes. The deterioration of the Atlas cedar forest in Algeria (Aures mountains, National Parks of Theniet el Had, Djurdjura. and Chrea) is one example; it constitutes in itself a major concern for the Algerian foresters and ecologists. Today, research programs are initiated with a view to identify the factors causing and worsening this phenomenon, which affects more than 50% of the cedar forest in the Aures. Moreover, the over-running of natural cork oak forest, in particular by Pinus halepensis in the centre and in the west of Algeria, and by Pinus pinaster in the coastal and eastern parts. Many actions are carried out by the forest administration aimed at protecting the forest and conserving its biodiversity, such as the creation of national parks, regional nature reserves and the so called integral reserves. In parallel, ambitious national programs of afforestation were initiated, at a rate of 60 000 hectares per annum. In addition, the propagation of exceptional and rare species is tested for their preservation and conservation.