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World forests.

Temperate forests expanded during the past decade, but the reverse was true globally. With deforestation running rampant in the tropics, the global forest contracted by perhaps 100 million hectares (247 million acres).

The "perhaps" is necessary in the absence of complete figures. The Food and Agriculture Organization of the United Nations (FAO) completed the first global inventory of tropical forests in 1981 with data from 76 nations. Advances in satellite imagery are expected to benefit a second FAO inventory of tropical forests now under way. FAO figures for world forests as a whole, both tropical and temperate, remain the best available and are the source for the tables that accompany this article.


About half the world's forests are temperate, and half are tropical. Throughout much of history, forestlands have been declining, and that trend continued in the 1980s with a vengeance. In the temperate regions, the hectares of forest are expanding, but these increases were more than offset by decreases in the tropical regions.

The majority of the world's forests are closed, their branches forming a canopy overhead that creates shade and prevents the growth of grasses and shrubs on the forest floor. Open forests and woodlands occupy drier locations and are more resistant to drought and fire. Grasses and shrubs grow between the trees. The FAO figures represent a spectrum of forests, open and closed, from the equator to the frozen higher latitudes, and from coastal mangroves to montane treelines.

The figures only hint at what is actually happening in the forest. A number reflecting the rate of deforestation does not even begin to convey the impact of an eroded field where a rainforest once stood. Temperate forests recorded a modest expansion because of trees growing on abandoned cropland. But at the same time, these forests of the temperate zones showed the effects of a crisis facing the developed nations: extensive forest die-back from a variety of causes ranging from air pollution to not-yet-understood blights. Europe, for example, may have lost 15 percent of its standing volume.


Forests in Canada, the United States, and Mexico were among those that experienced pollution stress.

In a joint Canadian-U.S. study of the sugar-maple decline in New England and Canada, scientists are investigating possible causes, including acid rain, ozone, drought, parasites, and poor cultural practices. The ozone being studied is not the beneficial high ozone that shields the earth from ultraviolet rays, but the toxic low ozone that damages trees and people.

Outside Mexico City, a popular park lost so much Abies religiosa, a fir held sacred by the Aztecs, that people began calling the park "the graveyard." Foresters attributed the dieback to automobile emissions, and they eventually clearcut and planted a more tolerant pine. Upwind of Mexico City, the sacred fir continues to grow well.


West Germans blame air pollution that crosses their borders for their forest dieback. Acid fogs caused by industrial and automobile emissions are believed to cause damage to trees through an aluminum toxicity that interferes with nutrient absorption. Experiments with forest fertilizers caused some recovery, but at the same time German foresters also began removing all sick trees, thus selecting for more acid-tolerant individuals.

The extent of the thinning was graphically described by a resident of the Black Forest, who said: "In years past, to read the newspaper in my cabin in broad daylight required a lamp. Now I need no lamp. "

German forests are largely manmade, with heavy plantings of spruce, and past forest management could be contributing to the present dieback. German foresters are studying natural mixed stands that may be more resistant to stress.


In 1985, the FAO published a Tropical Forestry Action Plan, enlisting the nations of the world in a coordinated effort to reverse tropical deforestation. A forest plan for each tropical nation was among the objectives. Bolivia, ninth in the top-10 forested nations of the world, is losing 117,000 hectares (288,990 acres) to deforestation each year. In a recently completed five-year plan, Bolivia gives priority to agroforestry projects, especially in the hard-hit high Andean region. Brazil, the second most-forested nation in the world, relies on forest conversions to raise funds needed to pay foreign debts. Brazil is losing 2.3 million hectares (5.7 million acres) of forest each year.


The FAO figures reveal that Africa, alone among the continents, has twice as many dry, open forests as closed, shaded ones. It also has the Sahara Desert, which continued to extend its southern reaches into the Sahel during the past decade. A prolonged drought contributed to the desertification, but deserts can also form in times of good rain if land is abused. Coastal deforestation may be feeding the drought cycle, and a major reforestation effort could ease drought conditions. Shelterbelts of trees between fields and other arid-zone agroforestry projects show promise, but the scope of the problem is vast.

U. S. S. R.

The Union of Soviet Socialist Republics has more forests than any other nation, but trees grow slowly in the frozen North. Russia has a long history of forest management, predating the formation of the U.S.S.R., and although the amount of logging was reduced in the past decade, the Soviet Union has the potential to become a major wood exporter.

ASIA India is one of the world's leading wood producers and has an advanced forest research program, yet India is suffering a fuelwood crisis. This Asian nation's deforestation rate has prove higher than FAO estimates, and the cause-as in many developing nations s a population explosion. India is hard on the heels of China and may replace it as the most populated nation on earth.

In java, the population has increased from 5 million to 95 million during this century, forcing landless people to clear upland forests for cropland. Indonesia, a leading wood exporter, will run out of trees if the current rate of deforestation continues. Japan, a leading wood products producer, buys logs from Indonesia as well as from the United States, Canada, Russia, and others.


Open and closed forests approach a balance in Australia, Fiji, New Zealand, Papua New Guinea, and the Pacific Islands. On many of the islands, water is the most valuable forest product, and island nations that protect their forested watersheds have the best water supplies. Australia, eighth among the top-10 forested nations, exports eucalyptus seeds for fast-growing tree plantations around the world. The Australian government recently announced a "One Billion Trees" program. The ambitious tree-planting project calls for planting one billion trees by the year 2000. The Australian Prime Minister, Bob Hawke, has committed $4 million for the first year of this regreening effort.


As the you-can-have-it-all decade advanced, so did atmospheric concentrations of carbon dioxide, methane, hydrofluorocarbons, and ozone. These gas molecules trap heat that would otherwise escape into space, creating a greenhouse effect that is expected to warm the global climate, raise sea levels, and bring on drought. The earth has adapted to temperature changes before and may again, though at what cost to existing species remains to be seen. If we are not ready to enter a brave new greenhouse world, can we at least slow the carbon-dioxide buildup?

Energy conservation and substitutes for fossil fuels would lower carbon emissions, as would reducing tropical deforestation. Most tropical forests are being cut to clear cropland, not for timber. The trees are left on the ground to dry, and then the whole area is burned. The carbon released by these deliberately set fires contributes up to 25 percent of the excess carbon in the atmosphere, but fossil fuels remain the chief culprit.


If we cannot eliminate carbon emissions, can we somehow remove excess carbon from the atmosphere? Roger Sedjo, of Resources for the Future, suggests that young tree plantations could serve as carbon sinks. During the early stages of a tree's growth cycle, it removes large amounts of carbon dioxide from the air. While releasing oxygen, it stores carbon in new leaves, branches, the trunk, and roots. How many trees would be needed to sink the 2.9 billion tons of free carbon added to the atmosphere each year? Sedjo estimates that it would require 465 million hectares (1 14.9 billion acres).

Is there enough vacant land for this many new trees? The degraded lands appearing in the tropics are prime candidates, since most tropical forests do not make good cropland. Once the trees are cleared and the site burned, not much is left in the soil in the way of nutrients. After several seasons of crops and pasture, the remaining nutrients are depleted. Continued use produces sites that can hardly support weeds. These "green deserts" (as they are sometimes called) spreading through the tropics will not be easy to plant to trees. Sedjo puts the cost of establishing and maintaining carbon-sink plantations on degraded lands in the tropics at $250 billion.


A U.S. power company is funding a reforestation project in Guatemala to offset carbon-dioxide emissions from a new coal-burning plant in Connecticut. Far-fetched? Maybe, but some see this as the ultimate think-globally, act-locally stratagem. The power company, AES Thames, went to World Resources Institute, a nonprofit environmental think tank, for ideas on how to mitigate 387,000 tons of carbon annually over the 40year lifespan of the plant. The Institute recommended the reforestation project in Guatemala.

Cosponsored by the Guatemalan Forestry Service and CARE (Cooperative for American Relief Everywhere), the project enlists 40,000 small-holder farmers to plant 50 million trees in woodlots and agroforestry plantations. The U.S. power company is earmarking $2 million for trees in its $275 million budget. The carbon trade-off could work, unless the farmers decide to harvest and burn their wood within the next 40 years.

The World Wildlife Fund and The Nature Conservancy recently agreed to absorb $9 million of Ecuador's foreign debt. In return, Fundacion Natura, Ecuador's leading conservation group, will receive comparable funds from the government to protect Andean and Amazonian national parks and reserves.

This is the largest of the debt-for-nature swaps initiated since the concept was coined in 1987 to encourage developing nations to resist environmentally destructive development. U.S. conservation groups assumed $13 million in foreign debt in earlier swaps-two in Costa Rica and one each in Bolivia, the Philippines, and Ecuador.


What does the next decade hold for the forests? The following professionals offer some educated guesses. Bruce Cabarle, a forester with World Resources Institute, foresees new sources of funding for tropical forestry, such as a greenhouse tax on oil and gas. "Whole nations could be taxed for their production of greenhouse gases," he says. "No one wants the World Bank to be in charge of the global environment. "

Roger Sedjo, senior fellow and director of a forest economics and policy program for Resources for the Future, projects a worldwide trend toward forest plantations. Just as agriculture evolved from hunting and gathering to cropping and livestock raising," he says, "so will forestry move from a foraging stage to the intensive management of wood plantations." He foresees less growth in the demand for solid wood, but increased acceptance of products like waferboard and newsprint that can be made from tree species once considered junk wood. Paul Miller, recognized as the dean of ozone research for the U.S. Forest Service, sees an urgent need to "do something about the traffic problems of the world's major cities"-especially the gridlocks-since an idling engine produces more carbon emissions than a moving car.

Working from a laboratory outside Los Angeles, Miller is confident that despite ozone, acid deposition, and drought, some types of forests will grow. "It's our job," he adds, "to manage around these problems. "

Katharine Hunter, of the U. S. Forest Service's forestry support program, believes that the next decade will reinforce the contention that tropical deforestation cannot be reduced without addressing the problems of the people, including individuals and families in refugee camps. She notes, Political instability is bad for the environment. " Richard Smythe, of the U.S. Forest Service's forest and environment research division, predicts a growing one worldness" as international ties become more and more obvious. He sees a large role for the world's media in increasing public awareness of the interdependence of all life forms. Timothy Resch, food and voluntary assistance coordinator with the U.S. Forest Service, predicts that agroforestry will come into its own. Attention will be given to the role of trees in supporting agricultural production, especially in arid and semiarid lands. Resch observes, "Foresters are by nature optimists who think in the long term, but one can see genuine reasons for optimism in the 90s." Even, so, Resch concludes that when it comes to the state of the world's forests, "Neither the Cassandra nor the Pollyanna view is accurate. "

Presumably, it's up to each of us to ensure that the Pollyannas of the world turn out to be more right than the Cassandras. AF






thousand hectares

(one hectare = 2.47 acres)

1 USSR 137,000 791,600

2. BRAZIL 157,000 357.480

3. CANADA 172,300 264,100

4. USA 102,820 195,256

5. ZAIRE 71,840 105,750

6. INDONESIA 3.000 113,895

7. CHINA 17,200 97,847

8. AUSTRALIA 65.085 41,658

9. BOLIVIA 22,'50 44,010

10. INDIA 5,393 51,8 1
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Author:Walsh, Barry Walden
Publication:American Forests
Date:Nov 1, 1989
Previous Article:Industrial forests.
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