Almost no one spoke out against the waste or the loss of irreplaceable older forests; resources were there to be exploited. The concept of sustainability hadn’t been invented; ideas like the land ethic were unimaginable; no one thought their grandchildren might want to see what the big woods looked and felt like. Everything got cut. After the move to the Rockies and the Pacific Northwest, the only thing that stopped the wave of deforestation was the Pacific Ocean.
All of this cutting was done with handsaws and axes; the portable chainsaw wasn’t invented until the 1950s. With that tool, one person can do in an hour what used to take two men two days. And now the chainsaws have moved south, to the tropical rainforests.
〜
Today the United Nations Food and Agriculture Organization (fao) is responsible for tracking the fate of the world’s forests. It does this by analyzing satellite images. During the 1990s the fao estimated that net forest losses averaged about 4.1 million hectares per year, worldwide. (A hectare is about 2.5 acres or roughly the size of two American football fields.) To put this number into perspective, 4.1 million hectares is the equivalent of two Massachusetts and represents 0.11 percent of the world’s total forestland. In a single decade, then, about 1 percent of the forest cover that existed worldwide vanished.
This isn’t the entire story, however. Statistics on net losses don’t change when ancient forests are cleared and replaced with scrubby second growth or with commercial oil palm or teak plantations. In many cases we’re swapping old, diverse forest landscapes for new monocultures and exchanging native trees for species that are exotic to the area. The net figures also hide a north-south divide: extensive loss of species-rich tropical forest is masked by an increase in younger, much-less-diverse forest types in northern latitudes. We lost an average of 6.3 million hectares of tropical forest per year during the 1990s, but the global net loss of forest was much less than this because of regrowth in the temperate, species-poor woodlands of China, Europe, and the United States.
Another issue with taking the numbers at face value is the way the fao defines forest: as land with 10 percent or more canopy cover by trees. Most people wouldn’t look at a landscape with 10 percent tree cover—or even 20 percent or 30 percent—and consider it forest; neither would most other species. If the fao defined forest as an area with 80 to 100 percent tree cover, the number of hectares that would be considered forest would be much smaller and the percentage-of-forest-loss estimates would be much larger. The definition also hides the impact of selective logging, usually sponsored by large companies that remove mahogany and other high-value trees for export to Europe or the United States. The roads built in these operations open pristine woodlands to poachers and squatters, and increase the risk of forest fire.
Finally, the fao’s figures don’t include the effects of forest fragmentation—of carving large, contiguous blocks of forest habitat into small bits surrounded by farmland or suburbs. In Brazil, researchers did this experimentally and documented two striking changes over time. First, large animals that demand a lot of space—jaguars, tapirs, and army ants—disappeared from the fragments almost immediately. Second, habitat quality declined dramatically within five years. This happened because so much edge was exposed to the surrounding pastures and croplands. The exposed forest edges dried out, large trees died and fell, and vines and weedy species from the surrounding developments took their place. The researchers found that fragmentation affects 1.5 times the area actually cleared.
We see the same thing happening at the edges of clear-cuts in the Tarboo Valley: the trees that form the border of the remaining intact forest have never been exposed to intense sun and wind. Many can’t change their needles and root systems fast enough to cope with life on the edge, and they die.
〜
According to the fao’s latest report in 2011, the overall situation worsened from 2000 to 2005—the most recent interval with data available. Globally, net losses of forest increased during that period to 6.4 million hectares per year, up from the 4.1 million hectares per year in the 1990s. Most of this increase occurred in the tropics, where net losses jumped from an average of 6.3 to 8.0 million hectares per year. The total area of tropical forest lost each year in the early 2000s was larger than the country of Panama; the daily loss rate was 219 square kilometers. On a two-lane highway, it would take you more than forty minutes to drive the perimeter of the area cleared each day. The rate of tropical forest destruction is accelerating as large companies convert forests with two goals in mind: establishing oil palm plantations to meet surging global demand for biofuels, and planting soybeans for animal feed needed by beef producers trying to satisfy increasing demand for meat worldwide.
The longer-term outlook is not good. More than 13 percent of the Amazonian forests are already gone, and less than half of the forests that once covered southeast Asia remain. Deforestation rates are increasing in Indonesia and Malaysia and in central Africa. If present trends continue, most of the world’s tropical forests will be wiped out by the year 2100.
Our older son worked in the Brazilian Amazon just long enough to become deeply discouraged about its future. For much of the season he was there, it was smoggy from fires set by large landowners who wanted to convert forest to pasture for beef cattle or to fields for soybeans and sugarcane. Fire-prone seasons in the American tropics usually occur when warm ocean waters move close to either the Pacific coast or the Atlantic coast and keep humid ocean air from moving over land, lowering rainfall. As the oceans warm in response to climate change, droughts in the Amazon are projected to become more frequent and severe, encouraging fires to burn out of control. Recent maps show Brazil’s “arc of deforestation”—a boomerang-shaped region with intensifying fire and industrial-scale cutting. Even though the vast majority of the logging is illegal, the arc is expanding to the north and west.
In the United States, the year 2000 was among the worst on record in terms of losses to forest fires: almost 3.4 million hectares burned. But in 1997 to 1998, 3 million hectares burned in Bolivia alone. Indonesia lost 8 million hectares that same year; in just one of Brazil’s Amazonian states, 5 million hectares went up in flames. The total loss of tropical forests that year was equivalent to half the state of California.
Recent work has shown that forest fire frequency is increasing outside of the tropics as well—creating what scientists call a positive feedback effect on climate change. The term is tricky—positive in this context doesn’t mean good; it means the feedback adds to or speeds up the process. When forests burn, co2is released and the total atmospheric concentration of co2rises. Recall that co2molecules, in turn, are efficient at absorbing infrared radiation that has been reflected from Earth’s surface, so that instead of being lost to space, the energy stays in the atmosphere and warms the planet. Forest fires increase co2concentrations in the atmosphere, which increase the probability of warm ocean currents and drought, which increase the chance of forest fires, which increase co2levels in the atmosphere, and so on. Fires create a positive feedback loop.
But there are also negative feedback effects on climate change. In this context, negative doesn’t mean bad; it means the feedback reduces or slows down the process. For example, plants use co2in the atmosphere as a raw material in photosynthesis. The carbon in carbon dioxide is used to make sugars and eventually cellulose, lignin, proteins, and nucleic acids—all the stuff that makes up leaves, roots, tree trunks, and strawberries. When co2increases in the atmosphere, then, it should act as a fertilizer. This prediction can be tested experimentally. If researchers augment co2concentrations by pumping it into the air above forests or prairies, productivity usually increases—plants get bigger. More sugars and cellulose and other compounds in plants means there is less co2in the atmosphere, so increased plant growth reduces the impact of greenhouse gases. It’s a negative feedback—it turns the thermostat down.
The interactions between positive and negative feedback effects are part of what makes predicting the ext
ent and nature of climate change so complex. But the ipcc reports have been consistent, and consistently correct: overall, the climate is warming. Forest fires will be more of an issue in the future, not less.
It would be cynical, though, for Europeans or Americans to lecture biologists and policymakers from the tropics about the evils of deforestation. Brazil’s arc of deforestation is analogous to the Mediterranean-to-Baltic cutting that occurred from biblical times to 1700 and the Atlantic-to-Pacific wave of forest loss that swept across North America from 1700 to 1990. What happened in the Tarboo Valley in 1895 is happening in Rondônia, Brazil, and Irian Jaya, Indonesia, today. Scientists from the industrialized countries are in the position of saying, “Do as we say, not as we did.”
On the other hand, research is showing that forest loss is probably not in the best interests of the tropical nations themselves. For example, recent work by European and Brazilian researchers has shown that incomes increase in the early years of forest conversion but then decline once the forest is gone. There is a boom, then a bust. The problem is that the productivity of cattle pastures and cropland declines in a matter of a decade or less as the thin tropical soils become exhausted. The bust leaves deforested areas in the same economic state as before—but without the timber, food, and water provided by the forests. An array of economists and biologists is now advocating agroforestry systems and sustainable logging based on native species as the best way to increase incomes long term. If further research supports the conclusion that sustainability pays, tropical nations may not need more than three hundred years, as the “advanced” countries did, to reach the conclusion that forests are good.
〜
My forester friend Mike Cronin likes to reminisce about a logger named Jim Johnson, whose son still lives in the Tarboo Valley. Jim made his living cutting trees. But in the 1930s, long before almost anyone else in the Pacific Northwest had the idea, he also replanted them. At the same time but half a continent away, Carl Leopold was planting pines with his family in Wisconsin. Before he retired, Jim harvested the Douglas-fir he’d planted as young man; in his mid-sixties, Carl built a home from trees he’d planted as a teenager. Both men were pioneers.
Carl planted trees throughout his life. In the 1950s and ’60s he planted pines with Susan near their home in Indiana, and in 1993 he initiated one of the first efforts to restore native rainforest vegetation in the tropics—on 145 hectares of derelict cattle pastures near the Pacific coast of southwest Costa Rica. Within five years, the fast-growing, weedy tree species he’d planted in Costa Rica were adding the height of a basketball hoop each year; some had trunks the diameter of a field-goal post. He’d planted them as a cover crop to provide shade and build soil for slower-growing, longer-lived trees planted underneath. After ten years, the canopy had closed; seeds deposited in monkey, bat, and bird droppings and carried in by ants had introduced almost a hundred native understory plants. Carl and his wife, Lynn, monitored the progress with instruments that allowed them to measure tree height, diameter, shape, and biomass. He authored some of the first studies ever published on the growth rates of native tropical trees and changes in species diversity in restored rainforest.
There are other reforestation efforts in the tropics—many others. Since 1977, members of the Green Belt Movement founded by Wangari Maathai have planted more than 45 million trees in Kenya. The movement employs local women to establish and maintain tree nurseries; movement staff also run seminars on civic engagement, women’s rights and reproductive health, and sustainable economic development. The success brought Maathai the 2004 Nobel Peace Prize and inspired the United Nations Environment Programme (unep) to start the Billion Tree Campaign with the aim of supporting a billion new trees planted worldwide each year. Fewer than five years after its inception in 2006, more than 12 billion trees had been planted and registered on the campaign’s website.
In Borneo, Willie Smits leads a group that is restoring rainforests at a 2,000-hectare site called Samboja Lestari. After being cleared by large logging companies and devastated by repeated fires, the area had become the poorest community in the district. In 2002, Smits’s organization, the Borneo Orangutan Survival Foundation, began planting 740 different species of trees in a design meant to discourage wildfire. Fire-resistant sugar palms—with sap that can be tapped to produce sugar and ethanol for fuel—were planted in large rings around diverse plantings of native trees. By 2006, the replanted sites were providing habitat for orangutans and yielding crops, firewood, and timber for local people.
Similar projects can be found on almost every continent. Deforestation has led to a full 38 percent of China’s total land area being classified as badly eroded; in response, the government instituted massive tree planting programs—though in some or many cases, exotic trees are being planted in monocultures. Even the cedars of Lebanon are making a comeback. Although replanting programs in Lebanon have been suspended due to political instability, Turkey has replanted more than 65,000 hectares in cedars since the mid-1980s. Oils distilled from the wood and seeds of these trees were used by the ancient Egyptians as a preservative in mummification; recent research suggests that the compounds may also have potential as a safe and biodegradable insecticide.
There are thousands of other projects, glowing like candles in the night. A scientific field called restoration ecology is flourishing, producing data on the best ways to replant forests and grasslands, reintroduce animals, and restore high-functioning ecosystems. We’ve come a long way since the first attempts at reforestation and ecological restoration, initiated by people like Jim Johnson, Aldo Leopold, and Carl Leopold.
So we are at a crossroads. A three-thousand-year-long wave of deforestation will probably be completed this century. And compared to what a well-capitalized investment group can do to a tropical rainforest in the span of a few months, reforestation efforts like ours seem like throwing pebbles into the ocean. But when thousands of people are throwing pebbles in thousands of places at the same time, things change. The rings from the splashes are expanding, reclaiming lost landscapes. Planting a tree is a way to apply hope. In restoration is the preservation of the world.
〜
The first thing to understand about reforesting an abandoned pasture, like the 6 acres east of the creek at our place, is that it’s hard, even in areas that don’t have clay soils like our Dead Zone. One of our boys found a research report that mentioned an old pasture in Washington’s Olympic National Park, surrounded by mature forest, that had not been grazed or hayed for eighty years. The field still had no saplings growing in it—even though tens of thousands of tree seeds had been raining onto it for the better part of a century.
Grass is tough. For small trees to have a prayer of surviving in it, you have to do something to break the sod. If you can scavenge old sheets of cardboard and lay them on a planting site, the grass will be smothered a year later and ready for a tree. Herbicides can be effective but have to be applied carefully; one year a crew from the county got too close to Tarboo Creek with their sprayer and treated both sides of the bank for a long stretch; the denuded sides gave way in the following winter’s floods and sent truckloads of sediment careening toward Tarboo Bay.
The Leopold family used to hire a neighbor to come in and plow, turning over the sod to discourage grass growth in that year’s planting sites. Many times, we mimic this approach by scalping a small rectangle of sod. We do this by taking a stout, broad-bladed hoe—an industrial-strength tool used for clearing fire lines—and whacking at the ground when it’s good and wet. Two or three thumps like this and we appreciate why tree seedlings have such a hard time. The grass roots form a netting so thick and tough it’s like peeling back a 3-inch-thick shag carpet. The sod sucks up every possible water molecule and every available nitrogen, phosphorus, and potassium atom, leaving nothing for little tree seedlings to grow on.
Grasses are particularly effective competitors because when soils dry out in late summer, the blades simply go dormant.
They start growing again when the rains return in late fall, or they just wait for spring. But young trees can’t do this. They still have green leaves exposed, and the leaves have to perform photosynthesis so the plant has something to eat. But to do that, they have to open pores in their surfaces and take in carbon dioxide. When the pores are open, water escapes. If it can be replaced from soil water taken up by the roots, the evaporative loss from leaves is actually a good thing—it cools them down and prevents overheating. In effect, plants sweat. If they can’t, and if temperatures spike, they can die of heat stroke.
So come early September, when the Northwest’s annual ten-week drought is starting to bite, the grasses have used up all the water near the soil surface and gone to sleep. Big trees can cope—they have roots deep below the surface and can easily find enough water to keep their leaves cool and moist. But saplings, with roots that barely penetrate the sod layer, are in a bind. All it takes is one good stretch of hot weather and they can burn up.
Saving Tarboo Creek Page 8