So glad you've joined the discussion, Abigail! IME the pine may rot sooner than some other types of trees, especially if the pileateds continue to pull chunks out of it, so you may find in 10 years or so that it's really crumbling. One vine that does well on tree trunks is climbing hydrangea, but it takes 5 years or so to get going and start blooming IME so I am not sure if it will be a good choice for your soon-to-be-crumbling trunks. Virginia creeper (a native) has berries for the birds, and since you mow the lawn around it, its tendency to sucker should be kept under control by the mowing. Both these plants climb by clinging with adventitious roots or holdfasts, both of which will cling to a broad surface link a tree trunk. VA creeper has lovely red fall color.

Twining vines will want supports attached to the tree trunk to allow them to climb. Lonicera sempervirens is a native honeysuckle that the hummingbirds like. It twines its stems around supports, and there are several different selections available. Clematis twine their leaf stems (petioles) and come in a wide range of flower types (large or small open flowers or bells) and various colors. Insects like my bell clematis flowers, but I don't see a lot of insects on the more open clematis flowers.

Avoid Euonymus since they can be invasive, and though it's a native with berries the birds enjoy, I assume you don't want poison ivy!

I have no recommendations for vines (not really knowing enough about them) but I enjoyed your photos. That was a grand old tree, and I love that you left the trunk. I thought that I was the only one to ever do that.

I posted a photo biography of our quaking aspen that went the same way as your lovely old pine:

http://forums2.gardenweb.com/discussions/3767068/m=23/the-lifetime-of-a-quaking-aspen-tree-in-pictures

I hope you post more photos when you find a suitable vine to cover the trunk. Will you also be planting a replacement pine?

Grape?

If you decide on Margarita, let me know - I'll give you mine. It is really too cold here for it so it never blooms, but it hasn't died yet. I travel to Durham for work, so we could probably find a spot to meet up.

Babs, just curious about why your Margarita doesn't bloom. Does it even form buds? Mine are just showing small flower buds, and in a few weeks will be in full bloom. The fact that yours survives is encouraging though. Does it stay green throughout winter there?

No, Bill, it really doesn't stay green through the winter. I planted it against the uninsulated foundation, figuring warm granite would help it out when combined with snow cover, but it just starts getting growing after being knocked back hard each winter when it gets cold again. So in October it will have reached a couple of feet, but then winter comes, and it's back to ground level by spring. It might be fine in a true 5a and probably has few issues in 5b and 6a, but it really limps along here. I was somewhat overly optimistic, but I figured if I didn't try, I'd never know. It's probably an issue of how cold it stays for how long here. It's perfectly common for it to stay below zero for a week or so most winters, and most winters it reaches within 3 degrees over or under -20 for at least a night or two, though this winter was surprisingly warm. I've considered trying it in a pot.

I have a 10 year old climbing hydrangea growing on an very tall dead ash with multiple trunks. No way was I going to take down a vine that took about 5 years to bloom and several more to reallly head up the trunk. Theash had been dying for years but when the branches starting falling off in high winds it was time for it to go.

Babs, it's great that you tried, but of course your zone really is too cold for "Margarita", as it's usually only rated to zone 6, or maybe 5b. I "push" a lot of plants even here in 6B/7A, but there are consequences. This year my camellias took quite a hit. I am pruning back the biggest "April Blush" from about 7 feet high down to at least 4 feet. I will have to prune back dead wood on the others as well, but I know they will all grow back. Still, there was significant damage, and nearly every bud was killed, so no flowers this year. I think the 9 below zero on Valentine's Day was one problem, but even more so was the very mild weather that persisted all through the fall and right into January. Then, the "real" winter weather came in all at once, and the plants didn't have a chance to adapt. Strangely, my gardenia "Frostproof" only suffered some damage, but 75% of it is green and looks fine. The southern evergreen magnolia "Bracken's Brown Beauty" is totally unharmed. Go figure!