system
Given the following post, respond as if you're commenting on Reddit:
human
What makes one type or species of wood harder than another?

On a cellular level, why are woods like oak, rock maple etc. so much harder than others like pine or cedar? Is it a different amount of lignin, or smaller cells packed tighter together? Do softer woods have thinner cell walls or weaker connections between the cells?
gpt
Don't know about the cellular level.

But trees that grow slower tend to have denser wood grain. I'd also venture to say it has Todo with environment. Drier, colder climates slow the growth rate. Heavily wooded areas will make a tree grow upwards instead of outwards, meaning more resources are dedicated to growing the main trunk instead of more branches.