Over the past 8,000 years, nearly one half of the forests that once covered the Earth have been converted to farms, pastures, and other uses. According to a 1997 World Resources Institute (WRI) assessment, just one fifth of the Earth’s original forest remains in large, relatively natural ecosystems -- what are known as "frontier forests". For more information see http://www.wri.org/trends/deforest.html.
Source: Dirk Bryant, Daniel Nielsen, and Laura Tangley, The Last Frontier Forests: Ecosystems and Economies on the Edge, available at http://www.wri.org/ffi/lff-eng/ (World Resources Institute, Washington, D.C., 1997), p. 12.
