This is an altered version of the mod Arborium by The_Evil_Pickle

I just updated it to work with Factorio 0.18 (and later) and fixed a few issues with the graphics in the new Factorio version. No functionality changes.

Allows you to plant trees, plus create automated wood production.

Trees now drop seeds when broken in addition to wood. These seeds can be grown into saplings in the Arborium structure, which can then be planted. Saplings will be the same type of tree as the tree you got the seeds from.

If seeds start to pile up in your inventory, you can burn them as fuel. Each seed gives 800kJ of power, which isn't a lot, but is still useful given how many seeds you usually end up with.
*In the settings menu for this mod, you can enable an option called "Seeds smelt to wood." When this option is enabled, seeds will not be usable as fuel, but can instead be smelted in a furnace to produce wood (4 seeds = 1 wood).

Additionally, the mod adds a second structure called the Mulcher. This can automatically break down saplings into raw wood and seeds. The Mulcher causes a significant amount of pollution, but the Arborium actually reduces your total pollution amount a little bit. Trees are good for the environment!

I know there are other mods that add wood production, but this one allows you to decorate your base with trees, and I think that's neat. You could also go on a quest to collect seeds for every kind of tree in the game if you wanted a challenge.