Variability and dynamic response of the cedar to climate change in the Eastern Middle Atlas Mountains, Morocco

Abstract

Climate change represents more and more a reality to master and whose impacts are important and it’s a necessity to limit them. On a global scale and particularly in Morocco, we expect an increase of temperatures as well as level of sea. The Moroccan cedar forest is subjected to a multitude of challenges and multi-form pressures leading to a regressive evolution of its ecosystems and to an imbalance of rural societies which live there, what makes it an interesting model for studying the climate change effect susceptible to affect the cedar forest ecosystem productivity in Morocco. The impacts of  climate change on the Moroccan cedar forest and the evaluation of their vulnerability have not been the object of a specific study yet. Thus, the dendroecology which has for support the measure of trees growth has data well adapted to study climatic factors impacts on forest stands productivity. The present work was conducted in a forest site named "Taoalt" located in the Eastern Middle Atlas. The sampling consists in taking 2 cores/tree from 20 trees of Cedrus atlantica M., wether 40 cores are extracted from the whole site. The obtained results show that tree ring chronologies going from 1498 till 2011 AD are very sensitive to climatic variations with a high mean sensitivity of 0,267 and important fluctuations noticed in the ring width evolution due to a specific natural disorder affecting the cedar forest. The Pearson's correlation coefficients indicated a negative and significant response (p< 0,05) of radial growth to monthly mean temperatures of June and October stemming from the meteorological station of Midelt. While precipitations of September necessary for the production of final wood influence positively the cedar growth. The low temperatures in winter (January) and especially frosts can lead to a strong reduction of the growth.