Fire probably kills seeds unless they are covered with an insulating layer of soil.
Mexican pinyon probably establishes from seed cached by birds and small mammals following fire. Fuel in uncut stands is mostly on the surface beneath tree canopies, which limits fire spread between trees. A single fire can reduce Mexican pinyon sapling density tenfold. Low-severity surface fires at 50 or 60 year intervals will thin Mexican pinyon, preventing development of thickets. Fire intervals greater than 80 years result in dense stands of Mexican pinyon and a build up of fuel.