I would leave the Poison Ivy except in areas where you are going to go. You're right, it is a great wildlife plant, especially the berries for birds, and you're also right in thinking that there is probably a lot of it all around you and the berries from your vines aren't going to add much to the supply of seeds that birds bring in. Even if you eradicate it completely from your land, which would be a tough task, you'd still have birds planting new ones. I'm not sure vinegar is any more environmentally friendly than Roundup. Both are chemicals, and at least Roundup is supposed to break down to relatively harmless chemicals upon contact with soil. I am not sure the same could be said of vinegar. ROundup is probably a lot more effective than vinegar at killing the plants you want to kill and not killing nearby plants. If i was trying to eliminate Poison Ivy (and, in fact, I am at my place) I would use ROundup. It will kill Poison Ivy, although it takes several applications before you stop seeing new shoots from the roots. Cutting or digging are likely to result in you getting a rash. For me, poison ivy has become a really serious rash anytime I toush it even a little, so I don't allow any to grow on my two acres, although I wish I could allow a nice berry-bearing vine or two to remain for the birds.

I've seen the western form growing lush and green after a spring fire. Cutting the vine near the ground does the exact same thing as fire, so there's really no point in burning. I provide the link below only because it discusses the ecological effects of fire on poison ivy. At home I think you are best off pulling with gloves, cutting near the ground, or using roundup. The roundup will usually do the job in one shot. Cutting will require many follow ups. Best to cut when the plants are in flower as that is the time they have exausted the most food reserves. Here is a link that might be useful: Fire effects

I just want to give an update on my poison ivy. After due deliberation and much consideration I decided I could carefully target just the poison ivy leaves with an Ortho poison ivy killer without it getting into the ground. I began with a small area first and waited to see what would happen. At first I thought perhaps it had no effect at all, but then a few weeks later I noticed that tiny patch I'd sprayed was brown and dead. So I sprayed the rest. It took a lot of patience and a couple of rounds to get it all and is a slow process just as daninthedirt said, but it looks as though it has finally succeeded! So my next step will be removing that patch of dirt and hopefully removing any roots with it and then bring in some fresh dirt. I figure that's the best way to assure I'm removing as much poison residue in the soil as possible. I'll wait awhile before doing this step to give the poison a chance to complete its job on that root system. I, of course did these courses of poison during long stretches of dry weather so it didn't wash off the leaves. Next time this problem arises I'm going to try the vinegar recipe method for comparison. Thanks for all the help and good advice!

I have had success with Roundup, but you do have to watch what else you spray it on. I would spray (and/or paint) the ivy that is growing up the trees; the Roundup will be absorbed and go to the roots. A few weeks later, I would start cutting the stems of that that tree hugging ivy near the base of the tree. When the roots send up new sprouts (and it will), give it a light shot of Roundup. Too heavy a dose will kill the leaves before the Roundup is absorbed. Continue sprayng every few weeks. Waplummer is correct; it will take a few years to really make a big dent in the poison ivy, but if you keep after it, there will be less and less every year. I am finally at the point where I only see a few plants every spring!