About 12 years ago I disowned a 30 foot square in my back yard and allowed it to go native.
I have about 10 species of trees including Red Oak. Eastern Hemlock, and Hickory that were preexisting on the lot line/fence row. I added a Paw Paw that came up volenteer in my indoor Schafelera and an All American American Chestnut tree to pollinate another elsewhere in the yard. I have Southern Magnolia, American Holly, Dogwood, RedBud and Spice Bush That found their way on their own. I have hundreds of maples and Wild Cherry that I as forrester cull out.
This winter I have 18 species of birds visiting the feeder and water in the yard and patio adjacent to the "woods". I have too many squirrels and a group of 3 or 4 chipmunks. The woods was developed as habitat and study area. The Red Breasted Woodpecker has been around for a year or so, but this year is dominant and unshy. When he wants the feeder, the others let him have it.
An avid amatuer botanist, I'm disappointed in the understory growth. I have a good growth of Virginia Creeper and pestiferous grapes, but no flowering plants. I've transpalnted a few native wild flowers but the heavy leaf cover apparently stiffles them out. They grow well however in the adjacent shade garden tended by my wife.
The woods is a cat free zone. Cats are severly punished for entering and stalking chipmunks and birds. I also allow all the spiders and don't discriminate against insects. I don't distinguish between good and bad insects. Like weeds, "bad" insects are considered mostly a human mental condition. The woods also contains my catipiller cage where I keep Wooly Worm larve to be hatched into breeding moths.
I have birdhouses sometimes occupied by Carolina Wrens and chickadees, but not always. My office has extensive glass doors and they are open in Summer mornings, allowing the wrensns to enter. Attracted by the jungle of house plants, they love to come in and poke around everywhere.
I have written before of the Hummingbird from hell, a summer diversion, and fun species to watch.
Your place sounds wonderful. Wish I had an office like that (and that it was actually in my home). I'm lucky to have room to move at work.