Western Wildfires and the Mississippi Delta: Lessons Learned about Ecosystem Management from Attempts to Control Mother Nature

摘要

Although human nature favors stability and consistency, this may be in direct conflict with the plans of Mother Nature, who embraces a more dynamic condition. This presentation addresses the unintended effects of United States policies put in place 100 years ago regarding controlling wildfires and the Mississippi River. Before the 1900's, frequent wildland fires sculpted the forest landscape, creating an open ecosystem of trees with fire scars at their base and a forest floor with little debris accumulation. Wildland fires are part of the natural process of a forest ecosystem; however, decades of aggressive fire suppression have drastically changed the look and fire behavior of western forests and rangelands. Our forests are growing older and thicker with tree densities on a "per acre basis" having increased to a staggering 40 times the natural condition. As a result, today's wildfires typically burn hotter, faster, and higher into the forest canopy than fires of the past. Because of this, the number of catastrophic wildfires has increased dramatically over the past few decades. Another example of implementing policy without a full understanding of the ecosystem and watershed involved the Mississippi River. Historically, the Mississippi River was uncontrolled and moved water and sediments to the Gulf of Mexico, a process that maintains wetland elevations and processes. In the mid-1800's, American engineers began to make the Mississippi River straighter, shorter, and deeper, lining the river with a corset of levees and dams. The intent was to make the river predictable and to increase navigation. The unintended result of this policy was to redirect millions of tons of sediments away from floodplains, contributing to chronic coastal erosion and reduced landforms. Clearly, government policy for the Mississippi River and for fighting forest fires created significant and adverse changes to the ecosystem. To their credit, the government was instrumental in recognizing the detrimental damages caused by girdling the Mississippi River and preventing forest fires and have begun to address the issues. However, there are no quick fixes to either problem.