Grandaflora rose is famous for rapidly overgrowing open fields,turning them into inpentrable thickets,producing a great haven for nesting birds and small rodents in the process.Unfortunately native successional growth is suppressed as a result.I think the firt step to restoring a woodland area is to ID and remove all the nonnative growth,and grandaflora rose is definately on the list.But,be advised,the process of clearing away any overgrowth is always going to result in other weed problems.The bare soil exposed around the base of the removed bushes will probably produce a bumper crop of whatever annuals that are in the area,and any desirable shrubs or saplings you expose from amoung the roses will definately be targeted by the deer,But any aesthetic goals you have in mine with your property requires the first step,get the weeds out.How about leaving the thorney brush in large piles to temporally provide cover for small animals,also allow the native brambles,that will surely sprout forth,to quickly recolonise the disturbed area as a foil to the deer,and cover for any plants you might be trying to reintroduce.

Multiflora rose is not without value as wildlife habitat, but I think the value you get is not worth the space it takes - even if you have unlimited space. Multiflora rose provides cover for birds and small animals that like dense shrubs. However, lots of native shrubs also provide that type of cover. In open, woodland edge conditions where Multiflora rose thrives there is usually plenty of cover, so removing the rose usually won't cause any problems. Multiflora rose also provides hips ("berries") that are winter food for a wide variety of birds. Many berry-eating birds eat the hops, and seed eating birds often tear them open and eat the seeds. Again, there are lots of native shrubs that also provide winter berries, and the fruit of most other shrubs seem to be preferred over Multiflora rose hips. THe big problem with rose is that is crowds out native shrubs and/or converts grasslands, woodland glades, and meadows into shrublands. It does support some wildlife, but does it support more than the habitat that would be there instead? I don't think so, and it is very aggressive in many parts of the country, actively spreading and crowding out native plants. The nail in the coffin of this plant is that it is miserable to walk in or around, so I am trying to remove all the multiflora rose from my property and urge you to do the same.

I'd also get rid of ASiatic Bittersweet, but I'd keep those large Grape Vines. I have seldom seen grapes actually kill a tree, and they provide lots of fruit, insects for birds, and add a new dimension of woodland habitat.

I would definitely attack the asian bittersweet first. Asian bittersweet is a major threat to your trees and everything else. Mature trees take a long time to get that way so whack the bittersweet first (cut high, cut low and repeat).
I also vote for getting rid of the multiflora rose. The ecological costs outweigh the benefits as the other commentators have noted. If you keep chopping it, it will greatly reduce in quantity. Let the cut remains thoroughly dry out and then you can trample or flail them into little pieces. Try to get it before it goes to seed but whack it whenever you can.
Clearing the multiflora rose does open up opportunities for other pests but it also opens up opportunities for good natives to volunteer in or be planted by you. Clearing out the multiflora rose also makes it more feasible for you to access more of your property to address other problems.
I would leave the grape alone except where it is a real hazard. I chopped some grape when I confused it with the dreaded porcelain berry and I regret it now.

Multiflora rose is the host for a virus which affects cultivated roses - another reason to get rid of it. RRD (Rose Rosette Disease) is spreading rapidly in this country after being imported by our Dept of Agriculture (the same Dept that originally imported the multiflora rose) as a control for multiflora. Unfortunately RRD also kills all other roses and is going to make growing ornamental roses very difficult. The Dept of Agriculture was warned about this but decided that it was more important to eradicate multiflora which is swallowing thousands of acres of pasture and crop land.

just a note - multiflora rose is the mockingbirds favourite food. so if you have mockingbirds it might be a reason - if not - get rid of it.

HERE is a great article in the current issue of Nature Conservancy magazine. Multiflora rose is one of our worst weeds. In Maryland it seems to take over every fencerow, streambank and roadside. Incredibly this weed was promoted by the U.S. Soil Conservation Svce in 1930's. The article recommends cutting the bush at the base and applying full strength herbicide.

Although it was originally recommended for wildlife, in the long run it is a serious problem, crowding out natives. I see no value in multiflora roses, and they are one of the many shrubby weeds I battle in field and forest.

I battle it too. I am happy to report that if you cut it to the ground, the stump can usually be pulled out the following year. Weakening it makes it so much easier than digging a fresh stump.