Virginia — …Slowly but steadily, the oak is disappearing from our forests and from our landscape. To use just one typical measure: In Shenandoah National Park, the oak canopy has shriveled by 20 percent over the past 20 years, according to a study funded by the Shenandoah National Park Trust. The oak’s decline is accelerating in a vicious arboreal cycle. There are many reasons for this, but one rises above all others. Oaks are fire-dependent, meaning they require frequent fires to regenerate. But fire-suppression efforts over the past century have broken this timeless pattern. Fire-intolerant trees with far less ecological value — maple, beech, basswood, black gum, tulip trees — have risen to replace the oak, hickory and pine forests, which need regular fire to open the forest canopy, bring in light and eliminate competitors. The best way to save the oak, and the countless critters that rely on it, is to return fire to our landscape. [A Washington Post subscription is required for full access]