Where I live there are many large ranches that remove certain species of trees. They go in with equipment and just shove the trees down.
I have also bought a lot where many of the trees were removed.
I see two ways to do this.
Option One: Once you have land, mark the trees you want to keep. Then get estimates from Tree Removal Companies.
These companies might be called arborists, tree services, etc. Many times the name of the company may be different in different areas.
Option Two: Hire or rent a piece of equipment called a "Bobcat", skid steer, skid loader.
With this option, the trees are not cut down. The trees are pushed over by the equipment.
Of
course, I can't quote prices for your area though where I live I can hire someone with a Bobcat for $750.00 or rent one for $500.00 and get someone like dear hubby to run it.
All this of course depends on the size of the land and how big the trees are.
Here are some example to explain: