Earlier quoted context omitted.
Go plant an oak tree. Not in theory, not a big plan for a monumental effort, just plant an oak tree. They survive for many lives of men and are a cornerstone for feeding the entire ecosystem. If you can't plant one where you're supposed to, plant one where you're not. It takes an afternoon not a lifetime.
Half of my property is woods and there are multiple fallen oaks that are slowly returning to the ground, but the canopy remains exposed. I'm constantly torn between letting "nature take its course" or speeding things up with a chainsaw and carefully sapling. I have also considered walnuts or fruit-bearing trees and slowly converting my land to something more akin to a food forest.
I think the best path is helping nature along to be the best that it can be naturally. There's a bunch of artificial gardening which would never sustain itself that ought to be avoided because it only looks like you're doing something worthwhile.
I'd highly suggest reading up on different keystone species for creating year round food sources for your local ecosystem with native plants and help nature along a little with a light touch.