I think it should be possible to harvest wood--not useable logs, just wood--from trees, without cutting them down. Perhaps a single unit, once a year, per mature tree.
Such wood could then be used for charcoal, sawdust, paper, etc.
If that were implemented, tree maturity time might be extended considerably, since the logs themselves would be more similar to stone (although perhaps also rendering a larger volume of charcoal, if burned.).
If fallen leaves were additionally harvestable, they might eventually be used as a fertilizer, helping to extend our charcoal supply.
Also, as far as fertilizers go, I'm hoping someday our dwarfs will be able to make Terra Preta:
http://en.wikipedia.org/wiki/Terra_pretaIt might end up being more expensive and labour-intensive than other fertilizers, but it lasts and lasts and lasts. Really amazing stuff. I'm trying to implement it into my garden, on a small scale.
Since charcoal can also be used to filter water, it might be used in a process to render murky pools into clean, drenable water.
Also, it's slightly off-topic, but relevant to the conversation:
I'd like to see coal tar as a byproduct of rendering coal into coke. It's got a ton of applications, from aniline dyes and drugs (tylenol):
http://en.wikipedia.org/wiki/Aniline#Usesto soaps/shampoos, and tarmac roads. It was even used in Egyptian mummification:
http://en.wikipedia.org/wiki/Coal_tar#ApplicationsI'm especially interested in the dyes, though.