Given that both the winner and the runner-ups are all in Europe. I suppose that other continents just don't have any trees of note.
EDIT:
> Taking second place is the majestic Portuguese Moreton Bay Fig.
> This tree was planted in the 19th Century in Coimbra's romantic Quinta das Lágrimas Gardens from seeds exchanged with Sydney's Botanical Garden and is a treasured landmark.
AHA!