Resources at Risk
|
Archived Articles
Species on the Brink
Resources at Risk
Good News
Get Outdoors |
U.S. Ecosystem Losses Linked to Population Growth WASHINGTON, DC, April 10, 2002 (ENS) - The loss of forest resources is real. Across the 50 United States, 85 percent of the original virgin forest was destroyed by late 1980s. Of the ancient, old-growth, forests, 90 percent has been lost.
In the Lower 48 states, from 95 to 98 percent of virgin forests were destroyed by 1990. For virgin eastern deciduous forest, that figure goes up to 99 percent. The loss of wetlands resources is real. The 50 states have experienced a 30 percent loss of wetlands in the 200 years from the 1780s to 1980s. Across the Lower 48 states, 53 percent of wetlands have disappeared during the same 200 years. These are not figures brandished by some wild-eyed activist with a political axe to grind, they are from a comprehensive assessment of the extent of ecosystem destruction in the United States prepared in 1995 for the National Biological Service by Reed Noss, Edward T. LaRoe III, and J. Michael Scott. At the time, Noss was editor of the journal "Conservation Biology." He is now chief scientist for Conservation Science, Inc., biology professor at the University of Oregon, an international consultant and lecturer, and science editor for "Wild Earth" magazine. Scott was then and still is leader of the Idaho Cooperative Fish and Wildlife Research Unit in the College of Natural Resources at the University of Idaho. The late Edward T. LaRoe III, was with the National Biological Service at the time their joint study, "Endangered Ecosystems of the United States: A Preliminary Assessment of Loss and Degradation," was issued. Published by the U.S. Geological Survey, it has become a classic in the field.
"Some temperate habitats," the authors say," such as freshwaters in California (Moyle and Williams 1990) and old-growth forests in the Pacific Northwest (Norse 1990) to name but two, are being destroyed faster than most tropical rainforests and stand to lose as great a proportion of their species. Because so much of the temperate zone has been settled and exploited by humans, losses of biodiversity at the ecosystem level have been greatest there so far." "The natural ecosystems of the United States have been significantly altered," declare Noss, LaRoe and Scott. Their list of ecosystem destruction goes on and on. Almost all black silt-loam and gravel hill tallgrass prairies of Indiana destroyed; 99.3 percent loss of original dry sand prairie in Michigan; 98 percent loss of bluegrass savanna-woodland and prairies in Kentucky; 90 percent loss of northern coastal bunchgrass in California, to name just a very few examples. With the loss of ecosystems, goes the habitat they provide for living creatures. Species at risk range from the well known such as Pacific Northwest salmon and Northern spotted owl, to the little known Shasta salamander, White-footed vole, and Florida weasel, to name a few from the long list published by Noss, LaRoe and Scott.
They lay the blame at human feet. "A review of recovery plans for 98 plant species currently listed as threatened or endangered by the U.S. Fish and Wildlife Service revealed that habitat destruction by human activities was the primary cause of endangerment of 83 percent of the species," they say at one point. Diana Hull, president of Californians for Population Stabilization, agrees. "Habitat loss due to population growth is the greatest threat to wildlife," she said Monday ahead of Earth Day 2002. "April 22 marks the 32nd anniversary of the first Earth Day, but the U.S. population has increased by 41 percent, from 203 to 287 million," since 1970, says Hull. U.S. Census Bureau projections indicate that the U.S. population will double to over half a billion by the end of the century. Californians for Population Stabilization believes that a curb must be placed on immigration to reduce the growth in the U.S. population. Former Senator Gaylord Nelson understood the population issue when he founded Earth Day in 1970 and he has not forgotten it. Nelson recently called for financial incentives to encourage smaller families and he called for reduced immigration levels. He asked, "With twice the population, will there be any wilderness left? Any quiet place? Any habitat for song birds? Waterfalls? Other wild creatures?"
Many other environmental groups recognize the same equation - human population growth crowds out the populations of other species, though they might not share Hull's desire to curb immigration. Zero Population Growth, a Washington, DC based advocacy group, says "Earth Day is a great opportunity to focus attention on the impact that population growth has on the environment and the urgency to preserve and protect our planet." The Sierra Club has refined its views on population growth and the urban and suburban sprawl that eats up open spaces, forested land, wetlands, and wildlife habitat. In its ongoing Challenge to Sprawl Campaign, the Sierra Club points to new research by Professor Rolf Pendall of Cornell University that shows that though population growth is rarely the sole cause of sprawl, it often contributes in a major way. The importance of population growth as a driver of sprawl varies across the United States - in the West and South it is significant, often a major factor; in the East and Midwest it is a minor and sometimes inconsequential factor. Land consumption is outpacing population growth by a great deal, the Sierra Club says. The organization cites a study by former mayor of Albuquerque and author David Rusk who analyzed 213 urbanized areas. He found that between 1960 and 1990 population increased from 95 million to 140 million, 47 percent, while urbanized land increased from 25,000 square miles to 51,000 square miles, 107 percent. Data collected by the Department of Housing and Urban Development for its State of the Cities 2000 report, which covered the years from 1994 to 1997, shows a continuation of this trend. U.S. urban areas are expanding at about twice the rate that the population is growing. So conservation groups of all persuasions, and lawmakers of good will at all levels of government and within all political parties continue to combat the loss of U.S. natural resources.
Noss, LaRoe and Scott make one "major" recommendation at the conclusion of their exhaustive study - "conservation plans for all ecosystems should be developed, starting with those that have suffered the most drastic declines and that are at greatest risk of further losses or degradation." They advocate an ecosystem approach to conservation so that when a "suite of species associated with an ecosystem type" qualifies for listing under the Endangered Species Act, "these species can be listed together and restored to viability through multi-species conservation planning." "The immediate objective of protecting endangered ecosystems could be accomplished," they say, "while working toward the longer-term and more difficult goals of representing all ecosystems adequately in protected areas, restoring degraded ecosystems to a natural and healthy condition, and managing ecosystems in reserves and multiple-use lands wisely." Copyright Environment News Service (ENS) 2002. All rights reserved. |
Clearcuts in the Gifford Pinchot National Forest, Washington (Photo courtesy 
Conservation biologist Reed Noss (Photo courtesy Conservation Science, Inc.)
Mine waste ponds at the Climax Mine, White River National Forest, Colorado (Photo courtesy American Lands)
Suburban sprawl consumes natural landscapes. (Photo courtesy 
The future of many rare species like this ferruginous pygmy owl is now in human hands. (Photo by Chan Robbins courtesy 