PALYNOLOGICAL DATA IN SUPPORT OF THE SURVIVAL OF WALNUT (JUGLANS-REGIA L) IN THE WESTERN MEDITERRANEAN AREA DURING LAST GLACIAL TIMES

This paper is based upon palynological data from Carihuela Cave (Grana da, southeastern Spain), that support the presence of walnut (Juglans regia L.) in the western Mediterranean during the early and middle las t-glacial stage. Pollen records of Juglans L. are closely associated w ith Mediterranean evergreen assemblages. particularly Quercus L., Olea ceae and other thermophilous taxa. Palaeo-climatic reconstruction, sup ported by sedimentological and palaeontological information, points to a further relationship between Juglans appearances and climatic impro vements. Growth in refuges close to the site is proposed, perhaps in i ntramontane river valleys of the Betic ranges. Finally, the possibilit y of early diversification in the western Mediterranean is evaluated t aking into account both the classical viewpoint about its allegedly fi rst arrival during Roman times. and other palynological data suggestin g a native character for walnut within the area. Some problems are dis cussed concerning the poorly understood relationship between cultivate d and wild relatives.