A pipeline easement has clearcut a 90 x 1500 ft plot of forested land in my 100 A in central Ohio.

A 50 x 1500 ft section is a permanent easement and will be replanted in grass. I can replant 40 x 1500 ft temp easement after construction is done. It was in mixed native species with no conifers. Will I have much success in replanting with seedling tress or should I let it grow with natural succession? I would expect major deer damage to seedlings.

My personal inclination is to not plant trees because, as you point out, nature will repopulate; also a plant that seeds in naturally will almost always outcompete one that has been transplanted there. However, if there are certain species you would like to introduce to the woodlot for aesthetic or wildlife purposes this is a great opportunity to do so. Establishing conifers can give cover and provide habitat for a variety of bird species and small game; deer don’t tend to bother spruce trees except as a last resort. If you choose to plant hardwood seedlings, I strongly recommend using tree tubes to protect them until they grow out to sufficient height that deer browse is no longer a problem (usually about 4 ft.).