Seeing the Forest for the Trees
August 14, 2011 | 6:05 pm CDT
A new study says global forest levels, as a whole, are experiencing transitions from shrinking to growing.

Could the world be looking at an increase in forestland? A recent study, published in Proceedings of the National Academy of Sciences of the United States of America, offers an encouraging perspective on the future of international forest levels.

The study, “Returning Forests Analyzed with the Forest Identity,” analyzed in detail the 50 countries reporting the greatest quantity of timber in 2005, as well as analyzing the 144 countries that reported timber volume to the United Nations Food and Agriculture Organization, using a new formula developed to measure forest cover called “Forest Identity.”

“Globally, we should celebrate the reversal from shrinking to spreading forest,” says Jesse Ausubel, the director of the Program for the Human Environment at The Rockefeller University in New York, NY. “The forest transition is spreading. Looking at today's entire world of 214 countries, we believe 69 have now experienced the transition. Thus, we foresee a great restoration of forests during this century, with ample area for habitat, good possibilities for carbon orchards and abundant growing stock for the wood products industry.”

Ausubel developed the formula along with researchers from the University of Helsinki and scientists from China, Scotland and the United States. Ausubel, a graduate of Harvard and Columbia, spent the first decade of his career in Washington D.C. working for the National Academy of Sciences (NAS) and the National Academy of Engineering. On behalf of the Academies, he was one of the main organizers of the first U.N. World Climate Conference in Geneva in 1979, an event that substantially elevated the global warming issue on scientific and political agendas. He also coordinated and authored much of the 1983 NAS report “Changing Climate,” the first comprehensive review of the greenhouse effect.

Additionally, he has led several activities of the United States Council on Foreign Relations concerned with the environment and resources.
Wood & Wood Products recently talked with Ausubel about the forestation study and his thoughts on the future of international forests.

Wood & Wood Products: Who funded the “Returning Forests Analyzed with the Forest Identity” study? How did you become involved in the study?

Jesse Ausubel: No specific grant supported the study, but organizations, ranging from the Academy of Finland to the National Natural Science Foundation of China, supported the authors. The roots of my involvement go back 15 years, when I first asked Paul Waggoner, the former chief of the Connecticut Agricultural Experiment Station, “How much land can 10 billion people spare for nature?” I expected that growing population and affluence would expand farming and logging and thus shrink forests to almost nothing. Instead, we began to find that many nations were experiencing transitions where increasingly productive agriculture and forestry and changing patterns of consumption were allowing land to return to nature. Anyone looking out the window of an airplane on a clear day flying over Maine, or Connecticut, or Minnesota sees a transition to more forest. In 2005, Finnish co-author Pekka Kauppi recognized that the six authors of the new paper were converging on a similar understanding and proposed we work together to define and quantify the forest transition, historically and globally.

W&WP: Could you explain the new formula to measure forest cover, known as “Forest Identity?” How does it work?

Ausubel: The Forest Identity simultaneously and consistently considers the area the forest covers (hectares or square kilometers), the volume of timber (growing stock in cubic meters), the total weight of the above-ground biomass (in kilograms) and the fraction of the biomass in carbon (again in kilograms). It reconciles the concerns of diverse forest stakeholders, some of whom value the area for habitat, some the timber volume that might be sold, some the biomass that could be fuel and some of the sequestered carbon that might reduce carbon dioxide in the atmosphere.

We call the equation an identity because the left side of the equation, namely tons of carbon, equals the area (hectares) times density (cubic meters per hectare) times biomass (tons per cubic meter) times carbon (ton of carbon per ton of biomass). This simple equation inescapably and powerfully reconciles diverse perspectives on the forest and allows easy translation of concerns from one variable to another. Crucially, the variables are measurable and are actually measured or can easily be estimated for most forests.

W&WP: Though the outlook on global forest levels as a whole is optimistic, countries such as Brazil and Indonesia have experienced losses. What are the reasons for these losses? Does the rest of the world actually make up for these losses?

Ausubel: The global forest area did shrink from 1990 to 2005, but had forests in just two nations, Brazil and Indonesia, not shrunk, global area would have expanded. Excluding Brazil and Indonesia, Earth's forests increased about 2 percent from 1990 to 2005.

Surprisingly, expanding cropland or harvesting timber products fail to easily explain the losses. Brazilian forests shrank four times and Indonesian forests six times as fast as cropland, including soybeans and palm, expanded. Because the USA gained forest area while producing two times as much roundwood as Brazil and four times as much as Indonesia, lumber, pulp and fuel production also fail as easy explanations. Because richer nations don't suffer deforestation, affluence also fails to explain the losses.

W&WP: What are the types of national policies that affect forests in the selected countries?

Ausubel: Several factors contribute to forest transitions, from decline to rise. They include higher crop and forest yields per acre, replacement of wood by other fuel, getting more lumber out of each tree cut and economic development accompanied by a rural exodus, as well as timber imports. The role of plantations versus natural forests increased. Government interventions of legislation, transportation, forest services, nature conservation, education, expertise and tree planting affected each factor. Consumers have changed, too. Twenty years ago, Americans bought about 65 million newspapers each day, while in 2006 they bought about 45 million. I sometimes say, only half in jest, that the Internet has conserved more forest than activist groups.

W&WP: Do you think the results of this study will bring any changes to forestation policies in the selected countries?

Ausubel: From 1990 to 2005, 44 percent of the 144 reported less timber volume, it is true. But 15 percent suffered no change and fully 41 percent gained timber. The good news of nations, both rich and developing, passing through transitions from shrinking to growing forests, dispels the fear of inevitable deforestation leaving Earth a skinhead. We hope the study will encourage those countries still losing forest to commit to a schedule for the forest transition.

W&WP: How will this study affect the woodworking industry? Do you see an increase in wood exports from countries with higher forestation increases?

Ausubel: By highlighting the compatibility of harvesting timber products with growing forests, the study should discourage misdirected restrictions on the forest industry. The study's calculation of a smaller impact on the world's natural forests when timber is produced from fast-growing plantations and from regions of fast tree growth should increase plantations and trade.

W&WP: The study shows a positive correlation between economic development and forest conservation. Can you explain this?

Ausubel: Poor nations suffered both losses and gains of forest. Impressively, both booming China and India increased their forests between 1990 and 2005. Among the nations reporting timber volume to the U.N. Food and Agriculture Organization, none with more than $4,600 gross domestic product per person lost timber volume from 1990 to 2005. Thus, instead of affluence depleting forest resources, good governance, national policies and changing tastes combined to improve both forests and income. Our study affirms strongly that richer is greener.

W&WP: Could you explain the use of plantations where wood is “farmed” for use in wood products? Do you see an increase or decrease in these types of forestation?

Ausubel: Foresters shorten the cycle from logging to harvest by planting fast-growing trees, by creating lumber orchards. If I were to concentrate on sequestering carbon that would otherwise be added to the greenhouse gas in the atmosphere, I would call my forest a carbon orchard. Sawing up 50 acres of plantations growing twice as fast spares logging 100 acres of natural forest. Foresters project that plantations will lower the present 67 percent of harvest from natural forests to only 25 percent by the year 2050. High yields in concentrated areas of forestry and farming are the best friend of nature, the way to spare large amounts of land for nature. However, I prefer the term precision forestry to plantation forestry. The key to high yields is smart, synchronized employment of water, information and other inputs.

* The complete “Returning Forests Analyzed with the Forest Identity” study, as well as additional forest studies by Ausubel and various colleagues, is available for viewing online:

Returning Forests Analyzed with the Forest Identity
Pekka E. Kauppi, Jesse H. Ausubel, Jingyun Fang, Alexander S. Mather, Roger A. Sedjo, and Paul E. Waggoner
Proceedings of the National Academy of Sciences of the United States of America
November 2006

Additional Forest Studies

Foresters and DNA
Jesse H. Ausubel, Paul E. Waggoner, and Iddo Wernick
In Williams, C.G., Landscapes, Genomics and Transgenic Forests, pp. 13-29,
Kluwer, Dordrecht, 2006.

On Sparing Farmland and Spreading Forest
Jesse H. Ausubel
In Clark, T. and R. Staebler, eds., Forestry at the Great Divide:
Proceedings of the Society of American Foresters 2001 Convention, Society of
American Foresters, Bethesda MD, 2002, pp. 127-138.

How Much Will Feeding More and Wealthier People Encroach on Forests?
Paul E. Waggoner and Jesse H. Ausubel
Population and Development Review 27(2):239-257 (June 2001).

Restoring the Forests
David G. Victor and Jesse H. Ausubel
Foreign Affairs 79(6):127-144, November/December 2000.

The Forester’s Lever: Industrial Ecology and Wood Products
Iddo K. Wernick, Paul E. Waggoner, and Jesse H. Ausubel
Journal of Forestry 98(10):8-13, October 2000.

Searching for Leverage to Conserve Forests: The Industrial Ecology of Wood Products in the U.S.
Iddo K. Wernick, Paul E. Waggoner, and Jesse H. Ausubel
Journal of Industrial Ecology 1(3):125-145, 1997.

“High yields in concentrated areas of forestry and farming are the best friend of nature, the way to spare large amounts of land for nature.”
– Jesse Ausubel
Director, Program for the Human Environment
The Rockefeller University

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