This photo is of trees near Salernes in the Var. The hearts of these trees are extremely old but during the 1950s there was a big frost which killed most of the trees, however the roots survived and grew shoots up around the sides. At some point the farmer cut out the dead cores leaving the strange groups that we see today. The trees are also pruned in a way that is a local peculiarity called the "coute au mouton"(sp?) basically the "sheared sheep look", which keeps the trees very short and thus easy to pick the olives. It does however rather limit the number of olives you can get from a single tree.
As always clicking on the image shows it enlarged and go here for last week's picture