Same here hairmetal... Most of the area is secondary growth due to clear cuts. Not to mention that clear cutting gives the exact site requirements for many if not all invasive species (like aformentioned callary pear, siberian elm and bucthorns), it also eliminates any trees that are concidered long term overstory trees, like oak, maples, many nuts and others. You probably wouldnt even see half of them until it was too late. Many of the species we want are at the middle or end of succession. Cutting down the tall trees sets back succession, not much different from a moderate to severe fire. The same can be said for clearing the undergrowth. The best thing to do, and i will say its quite time intensive, is to go through the lot you end up with and inventory every tree and plant you possibly can. You will have no idea whether it is desierable to cut, plant or augment the existing forest if you dont know what you have. Then you can start to identify plants that you wish to give more light by cutting some branches and ground cover. IF there is an area where it has a good gap but nothing desierable, then is a good time to plant what you want. Also a good idea to keep an eye for dying trees so you can plant what you wish before it falls or you cut it. Clear cutting generally does way more harm then good. So is going in and ripping out invasive species. You just create the conditions for these types of plants to grow creating more work. Mind you there are lots of species which can use a perscribed burn to germinate or really start to grow. The least I can say is that it is anything as simple as cutting the large trees or undergrowth.

On oaks, Hypoxylon (or Biscogniauxia as it has recently been reclassified) is basically something that takes advantage of dying trees or branches. It's more of an indicator of death and decline than a primary cause. In that article about the Ghirardi Compton Oak, I find the claim that "the canker is showing signs of retreating, now affecting about 9 percent of the tree" to be very dubious. Once Hypoxylon invades the sapwood, there's no "retreat" - you can't un-rot the wood. More likely, they've been pruning out branches as they die, and that 9% represents the most recently-dead portion that hasn't been removed yet. It looks like a tree on its way out in this Sept. 2014 image: Compared to moving day (June 2012): Although I can understand why it's sometimes tried with a tree that has some historical significance, I'd be surprised if the long-term success rate is very high on moving big, old trees such as these. Even if they were just digging the trench around it without lifting up the whole thing and plugging it into the ground again, that amount of root damage would be very risky. This post was edited by saccharum on Wed, Oct 22, 14 at 13:29

I have not seen any mention of Blackgums! Beautiful, large trees with truly blood colored foliage in the fall (They also provide little blue berries for the birds!). They grow fairly quickly and are pretty tolerant of drought conditions. Something we put in last year was a Princeton American Elm. Unbelievably fast grower and was bred to have resistance to Dutch Elm disease. There really is a reason they were so widely planted as street trees and would provide high shade for your front yard relatively quickly. They are also reputed to be very tolerant of city pollution. No mention of Red Cedar, either. Grows quickly, immune to virtually everything and has a nice grayish color which contrasts nicely with the dark greens of other trees. I have mixed them into our overstory oaks/maples etc. with podocarps, firs and deodars for a nice tapestry of color and texture. They give good cover for camellias from winter burn. Any kind of magnolia does well! We have planted virtually every kind we could find and they have distinguished themselves into overstory and understory nicely over the years. The Sweet bays smell particularly wonderful and are a good open, midsized tree without too much spread. They tend to get very thin in winter, however. The Little Gems have the advantage of blooming until frost without getting overly large. American Hollies are magnificent, but are difficult to get started for some reason. Once one is happy, however, they will take off. Mary Nells or Oakleafs might be a good compromise. River Birch, of course, is incredibly fast growing and would do well in your seasonally wet areas. They have beautiful yellow leaves in Fall, nice open shade in summer and gorgeous exfoliating bark. Finally, esh had a good suggestion in bald cypresses. We have one that is always commented upon by those who come over, especially in the Fall when the needles turn golden and carpets the ground around it. A truly beautiful tree and a fast grower. As he mentioned they do well in both dry sites and wet. The only difference to my eye is speed of growth and density of needles/boughs.

Do you really want something edible? Or something that looks nice and can survive the shade. There are lots of great edible options, but they are shrubs--witch hazel, spicebush, blueberries, juneberry, currants. There are some low growing blueberries, you might try them, and sweetfern, although it needs dappled sun, but since PI loves that too, it seems like you might have that. Understory plants--sweet woodruff (can be dried to make pot pourri, smells like vanilla), things in the mint family, mayapples (supposedly edible when ripe, they taste like soap to me), wild ginger (pretty dang spicy!), bear berry/knickknick, lingonberries, wintergreen, violets, fiddlehead ferns, touch-me-not/jewelweed (can use leaves for salve to alleviate PI). Pretty ones--forget-me-nots. Those may be poisonous though. Jacob's ladder, and monkshood, which is DEFINATELY poisonous, but pretty. Turtlehead, gentian, other types of ferns. Those are some I can think of for starters.