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Show 78 for total domination over wildfires, we have set up conditions vihich greatly favor destructive conflagrations." The conditions referred to are these: Pine needles and branches fall to the forest floor - the more crovided the trees are, the faster this happens. Shrubs groviing in the understory lose their leaves every autumn. Trees grow old, die, and crash to earth. In wet forests, this fallen material decays, but vihere the climate is dry, the dead vegetation accumulates into tons of fuel per acre. If fires don't sweep through every few decades to clear away the debris viith a light surface burn, fuel builds up to dangerous levels. Then, vihen a wildland fire does start, it explodes into a hot conflagration almost impossible to control. Light surface fires don't damage trees much because tree trunks are often fire-resistant. Thick bark on ponderosa pines and viestern larch trees acts as an insulator to protect the core of the tree from damage. Fire can even help these trees by destroying insects vihich bore into their bark. Ponderosas benefit additionally from fire because it gives them the space they need to thrive, and fire helps lodgepole pine in an ingenious way. The cones of one variety of lodgepole pine are sealed by secretions of pitch. Only after they've been heated enough by fife for the pitch to melt will the cones open to shoot out their seeds. Jack pine cones react in the same way, which has led to an unusual problem with a species of endangered bird called the Kirtland warbler. Kirtland warblers will nest only under low-hanging branches of |