"Roger Van Loon" wrote in message
...
There has been some discussion about ivy surviving on old stone walls,
even with the base severed. But that's another matter entirely. Then
the ivy has found soil and sustenance within the old wall - not so on
trees.

Won't you get a build up of decomposing leaves held at the bases of the
branches? Even more so if the ivy is creating lots of pockets where debris
can collect. if part of the tree itself is rotten as well I don't see why
this couldn't provide enough sustainance for the ivy to survive.

Martin