Renewing

Certain resources are renewable in default nodecore including lux and lode.

Dirt

You can renew dirt by leaching Humus or by putting Humus next to Grass and waiting for it to spread.

Stone

You can renew Stone using Aggregate. Aggregate costs Gravel and Ash and gives you Stone when dried. You can then turn the Stone to Cobble and Pummeling it with a Pick to form Gravel. After this you end up with Gravel and 4 Stone Chips. If you do this process twice you can pack the 8 Stone Chips into Cobble. This basically changes Ash into Stone.

Wood

You can infinitely renew wood. Trees can drop enough leaves to create around 1-2 humus or dirt nodes with some leaves left over. (Just wait for the leaves to grow fully.) (You can speed up tree growth by a bit if you pummel a growing node)

Pumwater

If you surround Stone in at least 5 Pumwater source nodes, eventually the Stone will melt into a Pumwater source.

Lux Cobble

Still figuring this out. It involves soaking, pumwater and lux flow rate Check out "minetest/games/nodecore/mods/nc_lux/renew.lua" if you want to look for yourself.

Lode Cobble

You can create Lode Cobble by putting a Glowing Lode Prill on nc_lux:cobble8 and Pummeling (to find the name of the block you are looking at press F5).