U.S. Forest Conservation May Increase Deforestation Elsewhere

The study predicts the loss of 1 hectare (2.47 acres) of previously inaccessible forest in Asia, South America, Africa, and the former Soviet Union for every 20 hectares set aside and protected in North America and Europe. In short, the forests saved in Europe and America are replaced by the felling of trees elsewhere.

"A small amount of forest conservation here can have negative worldwide effects," said Brent Sohngen, co-author of the study and assistant professor of agricultural, environmental and development economics at Ohio State University.

For the most part, foresters ignore timber supplies available in many of the world's tropical forests because these areas are expensive to harvest at current prices.

However, Sohngen's models predict this situation could change if forest conservation in North America and Europe raises world prices. "North America currently produces 35 percent of global timber. Conserving only 5 to 10 percent of timberland in a region that supplies such a large proportion of global harvests will increase harvests elsewhere, including tropical forests that presently are inaccessible."

Many scientists are concerned about the possible ecological implications from the decline of tropical forests: the loss of biodiversity and undiscovered species, increased soil erosion, and the reduction of plants that remove CO2 from the atmosphere.

The United Nations Food and Agriculture Organization points out that as of 1990, the tropics contained 60 percent of the world's inaccessible forests --- over 800 million hectares, nearly twice the area of the state of Texas.

Sohngen conducted the study with Robert Mendelsohn, a professor of forestry at Yale University, and Roger Sedjo, a senior fellow at Resources for the Future in Washington, DC. The results were published in a recent issue of the American Journal of Agricultural Economics.

The researchers developed a variety of models that examined how worldwide demand for timber might affect the conservation of forests across the globe between 1995 and 2135. They examined both current and predicted global timber supply, demand, prices, and harvest costs. Their analyses accounted for supply and harvest differences across several geographic regions and compared regeneration and forest development costs.

Part of the researchers' model examined two possible scenarios. The first assumes that 5 percent of North American and European forests will be preserved and the second suggests 10 percent of these forests will be saved.

Both scenarios predict that these set-asides would increase worldwide timber prices by 1 to 2 percent, while increasing timber harvests in other parts of the world by 1 percent. In the 5 percent scenario, the model predicts 1.4 million hectares of previously economically inaccessible forests are harvested elsewhere, and in the 10 percent case, an additional 2 million hectares of inaccessible forests are harvested elsewhere. These additional timber harvests would likely occur in tropical areas, Sohngen said.

Sohngen said simple economics helps explain why forest conservation in North American and Europe may increase deforestation in the tropics and elsewhere.

"As supply decreases through increased conservation efforts in North America, timber prices will rise, making it economically feasible to harvest trees from areas where it was previously too expensive," he said.

However, Sohngen said that the same economics that create this predicament could also play a role in solving it. Increased tropical harvests require expansion into areas of forest that have never been cut before. This demands the construction of roads and the transportation of equipment and labor into remote places. These outlays would be quite costly.

However, harvesting in already developed forests throughout the world eliminates these construction costs, resulting in higher profits. This increased profit margin acts as an incentive for better management of these areas.

Sohngen pointed out, however, that government tax breaks and subsidies for timber companies often work against sound management of forest lands. Many federal governments, including that of the United States, pay for new road construction to make forests accessible. Relieving timber companies of the construction expenses enables them to affordably harvest in previously inaccessible areas.

The model shows that these access costs play a critical role in the amount of inaccessible tropical forests that are lost to timber harvesting. Low access costs predict a loss of 150 million hectares over the next 50 to 75 years, while high access costs lower that figure to 50 million hectares.

Although none of their scenarios predict the elimination of timber harvests in the world's tropical forests, Sohngen said he believes most of the increase in timber production will come from second- and third-growth forests and from tree plantations planted specifically for timber. In the tropics, these plantations have primarily been developed on degraded agricultural land.

Sohngen pointed out that their predictions only apply to forest loss due to timber harvesting, which the model suggests plays only a minor role in tropical deforestation.

"Other local factors not considered by this model -- such as increasing development of agriculture -- may still pose a threat."