| Several other factors influence the way fires move. Wind can turn fires in unpredictable directions, surrounding or engulfing fire fighters in flames. It can increase the rate of spread and move flaming particles through the air, causing blazes to flare up in other places. | Topography is a variable that can be considered in simple terms or in advanced ways. For instance, a hill places the fire below closer to the fuels above, therefore making it easier for the fire to spread. Topography also influences the movement of air, and since warm air rises, an uphill slope pre-heats the trees above, allowing fires to move faster uphill than down. |
| Fires affect forests in various other ways. In intense fires, nitrogen, calcium, phosphorus, and potassium can be vaporized; and soil microorganisms can be killed up to 3 inches under the soil, but recover quickly. Mycorrhizal fungi growing on tree roots can also be killed by fire. Recovery of trees takes longer than other organisms. A year after the Yellowstone fires of 1988, grass and inch-tall lodgepole pine seedlings were spotted emerging from the soil. Certain plants have adaptations which help them recover more quickly after a fire. Chaparral shrubs benefit from their large root systems, as their taproot can grow to 3.5 feet in length after only three months. Other plants sprout from roots instead of seeds, giving them an advantage. |
| Animals can be severely affected by fires. Their habitats are most often destroyed, including their food source which means that even if they escape the flames, they have to find new territory. Many animals do escape from fires, and move to another area. Other animals which live in the surrounding forest come to feed on the new seedlings and young plants growing in a recently burned area. |
fire -- page 4 of 4
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[fungi] [plants] [forest life]
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