Lesson 2 Group Discussion- Fire in Protected Ecosystems: Friend or Foe

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Fire in Protected Ecosystems: Friend or Foe

In 1994, the Smokey Bear campaign”Only you can prevent forest  fires!”ålebrated its fiftieth anniversary, testimony to the long fight  humans have waged against the natural force of fire. The battle has  been successful: Forest fires are now suppressed throughout North  America, saving millions of dollars in damages every year. But what is  the cost to ecosystems of removing a natural cycle of disturbance and  succession?

Ecologists now know that many ecosystems have evolved in the presence  of fire and need periodic fire to develop normally. In ecosystems like  the Indiana Dunes National Lakeshore, maintenance of the natural  park-like oak savanna depends on periodic fire for the preservation of  its characteristic open habitat. Also, species such as jack pine need  the heat of an intense fire to burn off the pitch that protects seeds,  permitting normal germination. When fire is suppressed, jack pine  populations decline, and species that depend on jack pine habitat (such  as the endangered Kirtland’s warbler) are jeopardized.

Yet fire, however natural, also has real costs in managed ecosystems.  Historically, national parks have suppressed fire in an attempt to  protect valued aesthetic characteristicsnd associated tourism  revenues. This chapter describes the 1988 fire in Yellowstone Park, one  of the most visited parks in the U.S. National Park System. In a  controversial policy decision, park managers allowed the fire to burn  freely, destroying thousands of acres of forest. Was this the right  decision? Evidence from other ecosystems shows that letting the fire  burn was probably the right thing to do. In nature, forests are  subjected to occasional high winds and lightning-induced fire, forces  that create openings in the canopy of trees above. Opportunistic species  colonize these spaces, creating a mosaic of species of different ages,  shapes, and reproductive strategies. Periodic fires are usually moderate  in intensity and are confined to dry litter and understory plants, with  relatively little damage to older trees. In a sense, regular fires  remove accumulated “fuel,” reducing the potential for catastrophic fire  in a future blaze. Fire also provides a mechanism for the remobilization  of nutrients stored in plant and animal tissue. When fire is  suppressed, however, the result may be major changes in habitat  structure and species richness. In commercially valuable forests,  research suggests that fire suppression results in more, but smaller,  trees. And because dense vegetation is more vulnerable to drought and  insect pests, the system may be less able to withstand normal stresses  than a fire-controlled forest. Letting the fire burn may therefore be a  case of “short-term pain, long-term gain.”

Comment on your feelings about this topic. Do you think  the advantages of a forest fire outweigh the disadvantages or vice versa  and why?