[MOD][WIP] The Cataclysm, The Acolytes and The Forsaken

tree

"trees": {
     "__comment": "tree size variance. anything above 0 will be considered as tree placement, 
     and the size of the tree is determined within the sizes node declared above",
     "sizes": {
        "cataclysm_biome:trees:deadoak": {
           "small": 0,
           "medium": 2,
           "large": 10,
           "ancient": { "percentage": 10 }
        }
     },

I’ve never worked on a biome but I’ve been messing with these numbers. I don’t understand why it works though, the comment implies that the number determines placement. However if you put 0 on everything, the whole biome gets filled with medium trees still ?
I hope someone could give some clarification…