Trees with peeling, papery bark, like river birch, are generally more flammable than those without. And fine-needled evergreen shrubs and trees, like cedar, cypress, fir, juniper, pine and spruce, contain volatile saps and resins. Their dropped needles, left to dry on the ground – or the roof -- further increase the fire risk. Redwoods, a notable exception, are considered fire-resistant due to the tannic acid in their bark.

свернуть