Severity Assessment of Dieback in Green Cypress (Cupressus sempervirens L.) within the Western Traras Mountains (Northwestern Algeria)

The Common Cypress (Cupressus sempervirens L.) is a tree representative of the Mediterranean flora, and is traditionally associated with cemeteries, symbolising mourning in the Mediterranean region. Dieback in forest trees is a complex phenomenon whose responsible factors can be diverse and not easily identifiable and prioritised, and they lead to general deterioration, which often ends with the death of the trees. The objective of this study is to characterize symptomatologically the decline of green cypress in the mountains of the Western Traras. The experimental approach prevails in the installation of the sampling units through all the tasks of Cyprès desperis in the region of Bab El Assa and Marsa Ben M'hidi. These sampling units number 25, with a surface area of 10 ares, or 450 stems sampled. The overall dieback index estimated at 2.6564 shows that the stands sampled are at the beginning of dieback. The results obtained show that 36% of the stands are at the beginning of dieback. 24% of the stands are declining, while 16% exhibit severe decline. Therefore, monitoring and precautions are necessary for maintaining the health of the Cypress tree.