Whatever this vine is, it must not be killing the tree. From my own back yard, there was an original 3rd maple tree (all large - all the same species). The 3rd tree, in my opinion, perished because of Euonymus vines. A 2nd maple, the Euonymus vines had already started growing there too. I think the birds had dropped the seeds originally from a neighboring property. I was concerned for the tree 2nd tree, so chopped the 2" to 3" base of the Euonymus vine completely in two, thinking it would kill the Euonymus vine, and for a year or two it did not. It lived off the tree. I then had to literally rip it from the tree which was quite a job.
A neighbor also has an area with some Sycamore trees. There is another vine growing up them that looks similar to poison ivy, and then there is literally poison ivy growing on the trees as well. One tree is now totally dead, and since I've watched these trees (3 to 4 years), it appears the others are dying as well.
Perhaps some trees tolerate some vines, while other trees do not.
