How to make a vanilla block pull from a custom loot table?

Hi all. I've been experimenting with loot tables for a bit, and wanted to know how I can go about making a block pull from a custom loot table when: 

it's broken in a specific biome, and only that biome 
make sure it's from a naturally generated block.
not overwrite loot tables for the default vanilla block in other circumstances.

While the loot table contains a location check for the biome, I am unsure how to get the loot table to be tied to the needed block in that biome.