"Old" is just a number, Bunky

Biden forest plan stirs dispute over what counts as “old”

Groves of aspen, for example, can mature within a half century. For Douglas fir stands, it could take 100 years. Wildfire frequency also factors in: Ponderosa pine forests are adapted to withstand blazes as often as once a decade, compared to lodgepole pine stands that might burn every few hundred years.