Forests Are Expanding Worldwide, Aided by High-Yield Farming Practices

Published September 1, 2007

An international research team reports in the Proceedings of the National Academy of Sciences that 22 of the 50 most forested countries in the world have been gaining forest since 1990, reversing the trend of forest decline often associated with modern societies and rising populations.

Modern Growing Techniques

The countries with growing forest assets include the United States, Canada, much of Europe, European Russia, China, and India.

This growth has been enabled by high-yield farms, which grow more food per acre on the best-quality land and leave marginal land to trees; high-yield tree plantations with faster-growing trees; wood imports from the world’s faster-growing warm-climate forests; and the continuing rural-urban migration that substitutes kerosene for firewood in Third World cooking and heating.

Unfortunately, Indonesia, Nigeria, and the Philippines report declining forest assets.

U.S. Success Story

In America, a huge surge of timber harvest and farming expansion between 1850 and 1910 denuded 190 million acres of forest, says Proceedings article co-author Jesse Ausubel of Rockefeller University. Since then, however, high-yield crops and livestock have permitted forests to re-grow in New England, West Virginia, the Ozarks, and other marginal farming areas.

U.S. corn yields have soared from 25 bushels per acre in 1860 to more than 140 bushels today. Meat and milk production per acre has doubled since 1970.

The researchers for the article say expanded tree plantations are expected to lower the percentage of wood cut from natural forests from 67 percent today to 25 percent by 2050.

Article co-author Paul Waggoner of the University of Connecticut notes more of today’s U.S. wood harvest is coming from Southern forests that can grow twice as fast as Northern ones, and from tree plantations where species selection, fertilizer, and weed suppression hasten tree growth.

Mixed International Picture

French forest cover expanded from about 7 percent to 25 percent of the nation’s geographic area over the past century as wheat yields surged from less than 2 tons per hectare in 1950 to more than 7 tons per hectare with greater use of fertilizer, better seeds, and fungicides.

In Asia, 792,000 hectares of forest were cleared between 1990 and 2000–but reforestation programs in China and India added more than 1 million hectares of forests between 2000 and 2005. There are good reasons to believe the big Asian countries have now gotten rich enough to value trees and forests.

In the Caribbean, forests are recovering in Puerto Rico and the Dominican Republic, but Haiti has been almost entirely deforested by poverty and poor governance.

Environmental Scares Threaten Forests

One of the biggest threats to forests today is the First World’s fear of global warming. Third World countries that have been over-cutting their forests for firewood are now being discouraged from substituting fossil fuels such as kerosene and fuel oil.

The current interest in biofuels is also threatening forests in the United States, France, and Malaysia. The U.S. mandate for 7.5 billion gallons of biofuels by 2012 could trigger the clearing of millions of acres of heartland forests to expand corn production for ethanol.

Corn ethanol produces only a net 50 gallons’ worth of gasoline per acre per year, so even dramatic deforestation won’t make much of a dent in the annual U.S. demand for 135 billion gallons of gasoline.

Dennis Avery ([email protected]) is director of the Center for Global Food Issues (CGFI). An earlier version of this article appeared on the CGFI Web site and is reprinted here with permission.