life stones

Life stones are magical stones created by one or ore of the Nine to facilitate life underground.
Life stones vary in power, with the weakest having about a quarter mile radius and the strongest extending their power in over a hundred mile radius.
Life stones warm the affected areas slightly but more impressively life stones allow plants to grow underground without photosynthesis and they allow fungi to grow with no organic matter to feed on.
Life stones cannot be moved without ending their magic, so areas with life stones are hotly contested by many underground creatures of all stripes.