Does the area flood during heavy rains? Is it sand on top of clay?
If the flooding is minimal and there is a good bit of sunlight, i'd go with disease resistant crabapples. Crabapples can tolerate a wide range of soil conditions. Use some compost in the hole when planting them.
The area only floods 1 or 2 times a year. I did try crabapples and sawtooth oak but didn't have much luck with them. I would assume that there is rocky/clay below, but the sandy soil seems to be at least a foot deep. This 2-3 acre area has been open for 40+ yrs. The only thing that grows there are weeds.. I would like to thicken it up..
Not sure how many of you know about this or not, but it should be helpful in a situation such as this.....PA DCNR has a website that is very helpful in finding out what plants are compatible with what situations, and it really focuses on Native plants which is probably not a bad thing to do. Click on the plant smart tab and you should see soil types on the right side of the page. If the link below doesn't work, the website is iconservePA.org