When this part of Kentucky was settled it was common practice to keep 20 per cent of the new farm in woods in order to have a supply of rails for fencing and firewood for home use. Many of these woodlots were never totally cleared but are certainly not virgin timber, they supplied split rails for "snake fences" and post and rail fence construction. Even though selectively logged of their best timber and grazed by cattle and hogs, they began to mature a nice woodland through the 20th century. Huge spreading white ash, yellow oak, slippery elm, spignut hickory, butternut, and American elm left an open understory filled with spicebush and dogwoods.
Almost all these have disappeared since I bought the farm in 1972. We still have some nice walnuts and shagbark hickories but even the mulberries and sycamores are in decline. The black locust, the ideal fence post, survive but borers make them useless by the time they mature. Honey Locust and Osage Orange still thrive but I consider them weeds.
The woods that once were open enough I could see a cow that had gone there to calve a hundred yards away. Now the dead trees have opened the canopy and multiflora rose and bush honeysuckle grow rampant and it is hard to see ten yards in front of you and riding a horse, or even walking through the woods is impossible.
I do not think any crossbreeding or whatever will ever bring back what we once had.