Association of State Wetland Managers - Protecting the Nation's Wetlands.

The Compleat Wetlander: Why is Wetland Policy So Challenging: Ask Bailey!

Over the years I’ve often reflected on the complexity of trying to establish consistent wetland policies nationally.  It seems like it shouldn’t be so difficult.  But it is and the reason is simple.  The United States is a land of many ecosystems.

For example, in 1990 rice farmers along the lower Mississippi lobbied strongly for clarification about how the Section 404(f) farming exemptions applied to their rice farming practices.  EPA and the Corps worked together and issued a memorandum that addressed their concerns  A couple of weeks later EPA and the Corps learned that rice farmers in California were very unhappy with the memorandum because it addressed the lower Mississippi, where flood waters were used to provide water, but provided no useful clarification on the arid southwest, where irrigation was used.  Practices were different.


Because it’s in a different ecoregion.

Bailey’s Ecoregions of the United States organizes the landscape into areas with similar temperature and precipitation patterns.  It is an incredibly useful tool for managing wildlife populations, and a host of other activities that have an impact on agriculture, natural and urban landscapes.

Description of Ecosystems of the United States
Ecosystem Provinces:
Description of Ecological Subregions of the Coterminous United States
Ecoregions of the United States, Encyclopedia of the Earth

Back in college I learned that the United States “is the country with the most diverse ecosystems in the world.”  Not the most species, the most ecosystems.  This is because the U.S. spans the temperate zone with climates that range from arctic tundra to tropics and because rainfall varies from 7 inches in the arid West to over 460 inches on the Island of Kauai, one of the wettest places on earth

In addition our mountains run north to south, which is important when one considers the movement of glaciers. 

In Europe and Asia mountains run east to west and ecologists have speculated that many plants became extinct because they were trapped between mountain ice to the south and the creeping ice cap from the north during periods of glaciation.  But in North America plants could migrate north to south in front of the glaciers.  This is easy to see looking at the map of Bailey’s ecoregions as many ecoregions are elongated from north to south.

When I studied ecology in college we learned that ecologists in Europe separated plant communities based on the understory because the overstory (trees) was so similar.  However in the United States overstory plants are used to characterize ecosystems because there were so many diverse environments.

This diversity of ecoregions and the wetlands associated with them makes environmental policy and more specifically wetland policy very challenging in the United States.  There are so many different kinds of forests and grasslands and wetlands to deal with that policies that work in one part of the country don’t work in other areas, or even have the opposite of the intended outcome.  For example some indicators of hydric soils used the mid-Atlantic region don’t work in the Northeast because the shorter growing season influences the organic content of soils and makes upland soils look like hydric soils–hence the need to regionalize the wetlands delineation manual to correctly identify wetlands in different parts of the country.

 It requires careful thinking, testing and tailoring to make wetland policy useful and applicable to every region of the country.

Tools like Bailey’s Ecoregions are just one of the many science tools available to further our understanding of the world where we live and assist in the design of fair, balanced wetland policy.

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