Support Local Land Trusts and Parks
When it comes to preserving forests in your area, the work typically falls to local land trusts and local governments. If your community is considering an open space bond, support it so that new parks can be created and more forests and farmland can be preserved. If a land trust is active in your area, consider making a donation so that it can continue its work of preserving land, usually in partnership with local landowners.
Search for local land trusts with the help of the Land Trust Alliance, and you might just stumble upon a great local park to visit, too, like the Esopus Bend Preserve in Saugerties, N.Y., pictured here (with the author's dog).
If you own a significant tract of forest (despite vast national parks and forests, most U.S. forests are privately owned) consider selling a conservation easement on the land to preserve it from development (and reap a tax credit in the process) and/or developing a sustainable forestry plan so that any logging done on the property proceeds without hurting the forest's ability to support wildlife, now and in the future.
Related: How to Find New Local Hikes