The practice and policy of putting out fires.

In the 20th century, government agencies such as the U.S. Forest Service, the Bureau of Land Management, and the National Park Service became so adept at putting out fires that until 1970 or so, annual acreage lost to fire dropped to 15% of what it was before fire suppression. However, since then, and paradoxically due to the very policies of these land management agencies, wildfires have become more frequent and larger, sometimes burning tens of thousands of acres. The Western United States has this problem-- if you suppress fires in temperate forests, the shade tolerant understory builds up, increasing the fuel load and creating a homogeneous landscape. Fires can then do more damage when they occur, as the fuel on the ground both spreads the fire uniformly through the understory and brings it up to the canopy. In a forest left on its own, the natural fire cycle's burns would create irregular patches of habitat, with gaps in the canopy- letting in sun, creating a patchwork of differing vegetation types, not only increasing biodiversity but keeping fires from spreading uniformly.

Source: USGS, Status and Trends of the Nation's Biological Resoures, http://biology.usgs.gov/s+t/

Interestingly, fire suppression conducted on the Redwood forests of California has led to such a large scale build-up of dried needles that when fires do start they are not the small, manageable blazes of the past but massively destructive, and hard to suppress, firestorms. Redwoods have evolved the capacity, through bark that resists combustion, to avoid succumbing to small fires. Unfortunately, theser larger and hotter fires have the capacity to kill the Redwoods that would have survived without any human intervention. What naturalists did not understand was the role played be fire in the lifecycle of Redwoods; only the heat produced by the small, natural fires served to open the pinecones of the trees and spread their seeds to produce new generations. Thus, man's shortsightedness has both endangered current trees and decreased the potential for new ones to grow. This is why we must be cautious in applying new ideas and technologies, especially upon the natural world.

Semisane

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