My property is wet most of the time. I have several redbud trees growing under larger trees. That is not supposed to be the ideal environment for them but they are surviving and the blossoms are lovely in the spring. It is such a pretty little tree it would be worth planting one for a test if you could get a cheap one.

Two to three hours of sun is very little for most tree species. Beech would meet your needs, but I suggest you do some more research.

Cercis, Cornus, Sassafras, and Paw-Paw (forget Genus?) all would be good understory in Z5, and if flooding is prolonged may want to plant on mounds to keep root crowns dry.

Highest on my tree wishlist right now is Carpinus caroliniana (American hornbeam). Think it might work for you.

Here is a link that might be useful: American Hornbeam - UConn Plant DB

After taking out some of the spruce you might consider Hallesia carolina or Hallesia monticola as a replacement overstory tree. Hallesias (Silverbells) won't block as much light as Spruce does, and they are moderately tolerant of wet feet. You could plant Rhododendrons, Magnolias, and camelias and shade loving perenials in the understory

I just read about Paw-Paw last night in "Arboretum America: A philosophy of the forest" by Diana Beresford-Kroeger. It sounds perfect for what you want because it apparently does really well in shade or as part of the understory. It flowers but I don't know that it looks like. The fruit sounds wonderful.

Genus Asimina Triloba, Family name Annonaceae, zones 4-10.

Your pictures were lovely.

cnid

You mention hawthorn, they are superb for wildlife and flower around may (hence their olde english name is Mayflower) These will grow and flower in moderate shade as they are an understorye species within woodlands. However, you could plant a mix of both the hawathorn and blackthorn (though not advisable if you have children running around the place) the blackthorn flowers sometime around march when the hawthorn is coming into leaf and then the blackthorn comes into leaf when the hawthorn comes into flower so you get a nice splash of colour for longer and a good mix of green shades. Plus you can use the fruit of the blackthorn (sloes) to make Gin. Both these trees are easy to grow from cuttings or runners, and you can be happy when you see all the wonderfull little creepy crawlies and little birdies feeding, nesting and livging it up in you spiky little shrubs

YewTree