Being able to punch a tree and harvest wood with your fists is unrealistic and undermines the survival aspect of the game. Plenty of mods have been made to solve this problem, but Don't Punch Trees takes a simpler and more vanilla friendly approach. Matter of fact, DPT is a datapack, which means you can use it in vanilla Minecraft - or with any mod loader of your choice.

Obtaining wood

You can no longer harvest wood with your fists. Logs, planks, stairs, slabs, etc. will not drop as items unless you harvest them with an axe (bamboo can also be harvested with a sword). This does not include functional blocks like crafting tables, chests, barrels, etc.

Instead, you'll need to harvest sticks from leaves and craft them into planks. 4 sticks in a 2x2 pattern will give you 2 oak planks. (This can also be used as a form of uncrafting if you make too many sticks or want more wood out of your tree farm).

Since it can take a while to get enough sticks for a crafting table and a wooden axe, this datapack lets you craft saplings into sticks as well.

Is this compatible with mods?

Modded Wood Types

In order for this to be compatible with modded wood types, mod makers will need to edit the loot table of their wooden blocks to require an axe. It's also possible to create a datapack that adds compatibility if the mod maker didn't. Here's an example json file:

{
    "type": "minecraft:block",
    "pools": [
        {
            "bonus_rolls": 0.0,
            "conditions": [
                {
                    "condition": "minecraft:survives_explosion"
                },
                {
                    "condition": "minecraft:match_tool",
                    "predicate": {
                        "items": "#minecraft:axes"
                    }
                }
            ],
            "entries": [
                {
                    "type": "minecraft:item",
                    "name": "minecraft:oak_log"
                }
            ],
            "rolls": 1.0
        }
    ],
    "random_sequence": "minecraft:blocks/oak_log"
}

Modded Tools

If a mod adds an axe to the game, it must be added to the item tag minecraft:axes. If it's not in that tag, you will not be able to harvest wood with it. As with wood types, you can still make your own datapack if the mod maker didn't do this.