Cover crops aren't trees. To elaborate...

Cover crop seeds (basically grasses) and tree seeds are apples and oranges. You can spray grass seed on the surface of the dirt and it will grow into a meadow. The same can not be said for trees. They will be eaten by birds and mice and digested, not dispersed. They also don't germinate well when left on the surface of the soil.

It's also a matter of numbers - tree seeds are by comparison, incredibly expensive to harvest. There's an industry of people who will camp out in forests, stalk squirrels, and see where they're storing their nuts. Or they climb trees to manually harvest fresh pinecones. It's labor intensive and you need a permit to do it.

> There's an industry of people who will camp out in forests, stalk squirrels, and see where they're storing their nuts. Or they climb trees to manually harvest fresh pinecones. It's labor intensive and you need a permit to do it.

Given we don't have squirrels in Australia, I'd imagine the knowledge you're providing here around gathering and permits are not accurate to the company in discussion.

What if a drone were to shoot the seeds into the ground with such force that they would be buried 4-5 inches deep (which is, I would guess, the necessary depth for successful propagation)?

That's probably too deep for most plants. 1-2 inches is probably more realistic, with 2 being close to the max.

what does this mean?

I've added more context to the comment

You dont plant tree seeds by hand. You plant saplings, small trees well past germination.

Well presumably someone is planting the seeds for the saplings unless they are all clones.

That's called a tree nursery. Seeds are planted and germinated in controlled conditions on a few acres.

Once they're baby trees, then you go plant them by hand in areas that need reforestation.

It's more like 1 in 3, an order of magnitude better. And they'd be sown under cover in more controlled conditions before planting out; not just tossed in the ground.