Influence of decline on the yearly growth of in some cork-oak stands of western Algeria

Abstract: Cork growth characteristics of two cork-oak stands of western Algeria: M’Sila on thecoastline and Zarieffet in the mountain were studied from a sample of 43 healthy and 19 decliningoaks. Pieces of cork were taken in summer 2005 and their yearly increase measured using amicrometer. On the littoral, the cork of the healthy trees showed a fast to middle growth speed,with an average annual increase of 2.42mm. In mountain, however, the growth speed showedrather a middle to weak growth type with an average annual increase of 1.86mm. For decliningtrees, cork increases were smaller and varied on average between 1.87 mm/year (in M'Sila) and1.01 mm/year (in Zarieffet), thus representing a 46% reduction of cork growth between coast andmountain oaks. Such differences must be taken into account when establishing the rotationrhythm of debarking in each cork-oak stand.