sentences:  At high altitudes, they come in contact with forests of Scots pine and with the Savin juniper; the latter sometimes forming part of the shrubby stratum.The fact that these are to be found mainly in areas which have been exposed for a large part of the Tertiary and over soils considered "relictos", supposes a great antiquity for such groves.The harsh climatological conditions, with the surface of the ground undergoing processes of alternate freezing and thawing (cryoturbation), makes difficult the development of elevated brush.