The General Effects Of Fire On Wildlife

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The General Effects Of Fire On Wildlife Essay, Research Paper The General Effects of Fire on Wildlife Abstract: Fire is an important part of many ecosystems and helps maintain the condition of habitats for wildlife. The effect of fire depends upon many factors, varying from the type of wildlife to their different habitats. Fire affects ungulates through positive, but often, short-lived improvements in diets by allowing ungulates to consume new plant growth. Fire mediates species interactions thereby reducing conflict. Birds are often positively benefited or unaffected by fire in the short-term. The beneficial role of fire on terrestrial ecosystems is contrary to the negative impact of fire on aquatic ecosystems. The long term effect of fire on wildlife is the maintenance of

feeding areas by preventing succession of a habitat to its top state. INTRODUCTION Fire is an important part of many ecosystems, affecting wildlife populations in various ways, such as by changing habitat, affecting food supply or quality, or by altering interactions of species. Fire suppression has allowed forested areas to achieve a climax state which provides less forage for wildlife. While terrestrial wildlife is benefited by fire, aquatic ecosystems are negatively impacted by large fires through the increase in sediment flow. Fire is essential in maintaining biological diversity in the Northern Rocky Mountain forests. NEGATIVE EFFECTS – AQUATIC ECOSYSTEMS Contrary to the beneficial impacts of fire on terrestrial wildlife, aquatic ecosystems are negatively affected, such as

the decrease in fish populations by fire. In the North Fork Shoshone River adjacent to Yellowstone National Park, fish died from increased sediment flow during a heavy rainstorm two years after the canyon had burned (Armbruster, 1996). Fish are sensitive to sediment both in concentration and length of exposure. When fire clears vegetation on slopes surrounding a river, runoff from rainstorms carries sediment into the river, killing portions of the fish population by obstruction of the gills. REGROWTH After a fire it takes many years for all trees and shrubs to grow back to their former levels; up to three-hundred years in the northern Rockies (Fuller, 1991). Burned forests show effects many years after the actual fire. Forests at lower elevations grow faster than those at high

elevations. Fire and regrowth are part of a cyclic process like that of the seasons. Regrowth does not mean the fire caused the death of forest by only that it is at a different stage, as natural as that of an old forest. FIRE DAMAGE AMONG TREES Fire damages trees by a combination of crown, root, and cambium damage. Tress can lose twenty to thirty percent of crown before the fire affects its growth(Fuller, 1991. Thick growth of bark, like a ponderosa pine (Pinus ponderosa) and western larch (Larix occidentalis), protects against cambium damage. Cambium is a layer that produces new plant tissue. A tree s roots will only be damaged if the layer of duff burns away. Thick duff and deep roots are good protection. Thick trunked trees resist fire because their size prevents from heating

quickly. Deciduous trees resist fire better that evergreen (Syngonium podophyllum) trees because foliage contains more moisture and fewer organic compounds (Harrison, 1969). SUCCESSION Fire prevents plant communities from succession to a climax condition, therefore maintaining the habitat in a state which provides greater forage. Woodland caribou (Rangifer tarandus caribou) are adversely affected by crown fires in the short-term due to major losses of forage and the avoidance of burned locations by the caribou. However, these fires provide the long term benefit of ensuring some of the habitat will remain as jack pine (Pinus banksiana) forest, which provides greater forage quantity for caribou(Patent, 19??). Key deer (Odocoileus virginianus clavium) are also benefited by long term