Quercus rysophylla puts on a show way down south

Taking trees out of their comfort zone may have surprising results. Here are some photographs of Quercus rysophylla growing in Grigadale Arboretum in Argentina (38° S, 59° W), taken in June 2011 (late autumn). The leaves turned late, and turned a very deep red. From what I have been told, this does not happen in the species' natural habitat. It may be that the colour was the result of stress or disease as in the months following we found die-back (you can see the beginnings of it in the first photo) and had to prune severely in an attempt to encourage new growth and save the tree (at the moment it appears to be recovering). Has anyone seen colour like this on loquat leaf oak? Post a comment if so!

Quercus rysophylla