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Why are pine forests especially combustible?

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Stone pine trees with rounded canopies stand amid low shrubs and flowering yellow bushes in Donana National Park, Huelva province, Andalusia, Spain. — pine A stand of stone pines (*Pinus pinea*) in Doñana National Park near Seville, Spain.

Pine forests are highly combustible primarily due to their high content of resin, a flammable substance found throughout the trees. This flammability is further exacerbated during hot, dry weather conditions, which reduce the water content within the living needles, making the forest more susceptible to wildfire.12

Despite this vulnerability, many pine species have evolved to depend on fire as an ecological disturbance for regeneration. In these fire-dependent ecosystems, periodic fires are essential because they clear the understory and expose bare soil, which provides the necessary conditions for seed germination and establishment. Furthermore, some pine species possess cones that are specifically adapted to survive fire, protecting their seeds from the heat before opening to release them onto an ash-fertilized seed bed.12