Auto Planting Forests Mod 1.18.1/1.17.1/1.16.5 has just changed items so they can plant themselves automatically on the ground. They will do that instead of de-spawning anymore.

Auto Planting Forests Features
As normal, once objects despawn, they will vanish.
With the new release, they will place themselves in the ground and grow.
That change can create an immersive and self-re-growing wood.
Details
If you cut down a tree, its leaves are still existing. They will gradually generate saplings which despawn afterward.
However, chopping one tress can start many that self-plants.
The mod can run on the Data Tag of “minecraft:saplings”.
The config file will be available to supplement more blocks.
Auto Planting Forests is a farming mod. To activate it, please install Minecraft Forge!
Screenshots