Assessment and growth of atlas cedar plantations, cedrus atlantica (Endl.) Carriçre, in Algeria: Study in the djurdjura and blida atlas ranges

This study was conducted in three Atlas cedar plantations in Algeria’s Djurdjura range and four others in the Blida Atlas range. They differ in their ecology and in the methods used to prepare and establish each plantation. By showing the influence of these different conditions, the study aimed to compare the vertical, radial and diameter growth of these plantations with other natural and artificially established cedar woods in Algeria, Morocco and France. A descriptive analysis of the dendrometric parameters confirmed the productive potential of Atlas cedars and their ability to colonise mountain areas. This conclusion is based on the exceptionally high success rate deduced from the inventories, which is higher than 80% in every plantation, with radial growth of up to 5.6 mm annually. At 34 years, the trees have an average diameter of around 40 cm and a dominant height of 16 m. Although the parts of the plantations that have been maintained are successful, the initial reforestation volume has been halved due to livestock grazing. The study results show the positive effect of holm oak coppices on the establishment and growth of cedar saplings, and the importance of preparatory work to stabilise the steeply sloping terrain and improve water circulation in the soil (banks and terraces). Although the cedars grow satisfactorily in dry zones, they seem to be more productive outside their natural range of distribution, in Brittany for example. Thanks to its adaptability to difficult conditions (drought) and its productiveness, this could be a promising species for reforestation and woodland improvement in Algeria.