U.S. Saves Only the Lands Nobody Wanted
By Cat Lazaroff
WASHINGTON, DC, August 27, 2001 (ENS) - America's large system of nature preserves fails to encompass the full range of the nation's biodiversity, a new report shows. The study by U.S. Geological Survey biologists shows that the United States has selectively protected lands that lack commercial, agricultural or other human values, leaving entire ecosystems unrepresented.
But according to an article in the August edition of the journal "Ecological Applications," U.S. nature reserves are not accomplishing a critical task: preserving the biodiversity of plant and animal species present in the lower 48 states.
The research demonstrates that despite covering about 420,000 square kilometers, America's arrangement of nature reserves fails to encompass the full range of the nation's biodiversity.
The research team, led by J. Michael Scott of the U.S. Geological Survey, Department of Fish and Wildlife at the University of Idaho, built upon past studies, some of which illustrated that as much as one third of vegetation types are not found within protected lands.
Their conclusion: nature reserves are unevenly distributed across ecological zones, and therefore preserve only a small portion of the plants and animals that call America home.
"The current network of nature reserves in the coterminous United States is the result of lands being set aside not in accordance with a well thought out ecological plan, but rather because the lands lacked value for commercial uses, human habitation, or because of scenic or recreational value," argues Scott, primary investigator for the study. "These 'lands nobody wanted' don't come close to representing the natural variation found in the U.S."
The authors divided the lower 48 states into three broad ecological domains: Eastern Humid, Western Humid Temperate, and Dry Temperate domains. They then combined soil productivity data with elevation and land management information to identify 35 potential soil and elevation classes within the lower 48 states.
The richest soils tend to be at lower elevations, and these areas are often more developed for agricultural use, timber production and residential development.
The authors contend that by disproportionately locating reserves in higher elevations with poor soil productivity, entire species of plants and animals who reside in lower and more fertile areas are left largely unprotected. Past studies have shown that the greatest numbers of amphibian and reptile species in the western United States are found below 2,000 meters of elevation, while many reserves are confined to higher elevations.
In order for America's biodiversity to be preserved for future generations, the authors point out that the private sector must be encouraged to protect plant and animal species outside of designated reserves.
There are some signs that policy makers are heeding this call. The recently passed Refuge Improvement Act of 2000 calls upon the U.S. Fish and Wildlife Service's National Wildlife Refuge System to be representative of the nation's ecosystems, giving the agency the authority to take measures to ensure better representation of species not currently under the purview of public lands.