Cedrus atlantica from Morocco has been used to reconstruct regional precipitation patterns (Stockton 1988), the North Atlantic Oscillation (Glueck and Stockton 2001), and even in Northern Hemisphere temperature variations over the last millennium (Mann et al. 1999). The species is described to be highly suitable for such analysis because of its precipitation sensitivity and long lifespan.
In order to update some of the existing records, and to further increase the sample replication particularly of younger trees, new samplings and re-samplings of cedar sites in the Middle and High Atlas were performed in 2002. Here we present preliminary results on three of these sites that represent quite different ecological habitats in the Middle Atlas of Morocco. We then present the setup for a climatic analysis of cedar ring width variations, and demonstrate the high common variance between detrended site chronologies. This result is astonishing, since the chronologies represent data from three sites that differ in aspect, elevation, total rainfall, soil layer and moisture availability. The maximum ages recorded at the sites range from AD 1784 to AD 982, and mean ring widths from 0.71 to 3.05 mm/yr. These differences in growth, however, are largely related to the amount of rainfall and local soil of either basaltic or limestone origins.