We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember "Spamlet"
saying something like:

Most of the trees that
blew down in the great storm were planted trees.

I paid particular attention to this 'cos I was out and about at the
time. Many (probably the majority) were previously inner trees that had
their surrounding shelter trees cut down for development areas/gardens.

Shelter trees on the outskirts of a woodland (even a small one of a
handful of trees) develop much greater and stable root systems than the
ones inside the group. As a result, when a giant blow comes along and
the shelter trees have gone, the inner trees are more prone to being
blown over than the shelter trees ever were.