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Weathering El Nino: hardest hit and perhaps the most overlooked, the world's forests could feel the effects for generations.

This year's El Nino, the periodic warming of Pacific Ocean waters that can radically alter the earth's weather patterns, has been the strongest ever recorded. It has contributed to floods, droughts, and sea surges and significantly affected fisheries and marine mammals. Its greatest effects, however, were felt in the world's forests, where El Nino's droughts had more of all impact than its rains. More tropical rainforest burned in 1997 than at any time in recorded history. This spring and summer saw smoke from forest fires raging over several million acres in Mexico and Central America, obscuring parts of Texas and spreading sooty, haze as far as Florida, Oklahoma, and Wisconsin.

Forest fires sparked by agricultural clearing and other human activity were sustained by El Nino droughts, creating tinder-like conditions in normally damp rainforests and delaying rains that mark an end to the "fire season." Fires of historic dimension raged in Mexico and Central America, as well as in Australia, Russia, Kenya, Indonesia, and the Philippines. The Indonesian fires, burning for months on the island of Borneo, destroyed more than 5 million acres of tropical forest and sent a pall of smoke across Southeast Asia that killed hundreds and left tens of thousands suffering respiratory ailments. Damage from the haze alone was estimated at $1 billion.

Brazil saw its settlement-driven Amazon fire season expand by 50 percent between 1996 and 1997. Along with drought and fire in its northern states, Brazil lost another 5 million acres of tropical forest, including endangered Atlantic rainforest habitat.

A survey of U.S. foresters and resource managers across the country found that although El Nino news coverage focused on dramatic storm footage, loss of life, and property damage, America's trees and forests bore the brunt of it. That will continue through the 1998 fire season and for years - even generations - to come.

"This was a unique historic event to the forests," says Maine Forest Service Director Chuck Gadzik, of a massive January ice storm in New England and eastern Canada that climatologists say was created by El Nino. "We had 8 million acres of trees damaged, about one-third to one-half of the state's forests.

"We saw severe damage to 2 to 3 million acres in the southern half of the state. Ice buildup over the course of days led to limbs and stems breaking off. Many trees just collapsed under all that ice weight," Gadzik says. "More vulnerable species like aspen and birch suffered worst, but oak and maple and other hardwoods, because they predominate, experienced the highest tolls. The effects will be with us for the next 40 years or more."

Along with small private woodlots in southern Maine, the ice storms also took a huge toll on the state's urban and community forests, with some 300 cities and municipalities affected, including Augusta, Waterville, and Lewiston.

"Open-grown trees with bigger crowns and more exposure are more at risk," Gadzik explains. "Street trees saw much more damage. There are now battles all across the state over removing versus repairing neighborhood trees. When you've grown up on a street full of old maples, you hate to see them killed."

More than 6 million acres of forests in New Hampshire, Vermont, and upstate New York also suffered damage from the ice storms. The U.S. Forest Service estimates that 20 percent of New England's Northern Forest experienced severe, long-term damage. Thousands of community shade trees were destroyed, thousands of gallons of maple syrup lost, and thousands of miles of recreational trails and rural roads made unsafe by hanging branches and fallen debris.

El Nino also promoted and intensified tornado and storm activity in the Southeast. In Alabama 34 people were killed and some 5,000 acres of trees knocked down in April when deadly tornadoes struck. Forest officials said the trees would have to be removed before they became an environmental threat by damming creeks or providing homes for tree-killing Southern pine beetles, already detected in 51 of the state's 67 counties.

Last November, in an early El Nino phenomenon linked to a splitting of the jetstream over the Rockies, a massive low-pressure system spun off 120- to 150-mile-per-hour winds that traveled east to west along the Continental Divide, knocking down trees like match-sticks. "The trees got blindsided; they were caught leaning the wrong way," (into the prevailing winds) says Frank Cross, of Routt National Forest near Steamboat Springs, Colorado. The hurricane-force winds downed some 4 million trees, cutting a swath 30 miles long by 5 miles wide. "There's some areas up to 4,000 acres where every tree is down," Cross reports.

In the wake of the disaster the Forest Service will allow salvage logging on at least 3,000 acres of downed trees. It also plans a two-year study of spruce beetle habitat to see if the region is at risk for a future epidemic and, if so, what can be done. Officials will also keep an eye on root disease, since most of the trees toppled over with their root balls exposed.

In New Mexico, Arizona, and other parts of the Southwest, El Nino's rains triggered unprecedented desert flower and cactus blooms and a revival of wildlife ranging from Javelina pigs to (disease-carrying) deer mice. Foresters worry that the eventual drying of this floral abundance will present serious fire risk for wooded areas, as will the rain-fed appearance of swarming termites and wood-boring beetles.

In Oregon, Washington, and other parts of the Northwest where massive clearcut logging operations have taken place on mountain slopes and along rivers, El Nino's rains and big surf contributed to what has become a regular pattern of landslides and flooding. When heavy El Nino rains hit Seattle, both the local and national media used the opportunity to report how development, surface paving, and loss of forest cover can accelerate coastal slides and erosion.

In California, where coastal damage has been severe, state forestry officials are pleased by El Nino's heavy winter rains and increased Sierra snow pack (150 percent of normal), which have recharged the water table and increased the moisture content of the trees. "We normally have our fire season starting in March or April. This year we may not see it 'til August," reports Karen Terrill of the California Department of Forestry. Terrill and others are worried, however, that this year's abundant, thick grasses that turn to hay in late summer may result in more dangerous, fast-moving grass fires.

In the Hawaiian islands El Nino weakened the trade winds that normally bring rain, resulting in a three-month-long winter drought on Maui and the Big Island of Hawaii, parts of which normally receive close to 200 inches of rain a year. Along with damaging crops like sugar, pineapple, exotic flowers, and Macadamia trees, the drought sparked wildfires that wiped out hundreds of acres of endangered native species, including kiawe and koa trees, and for a time threatened the Big Island's remnant rainforest, where tropical ferns dried to tinder.

While the historic 1997 to 1998 El Nino, with its dramatic impacts on trees and forests across the United States and around the world, may now be behind us, scientists are warning that it could also be a taste of things to come as industrial greenhouse gases promote a warmer, less stable planetary climate.


Heavy beach erosion on the north coast of Oregon following a series of El Nino-linked winter storms has revealed an ancient forest. Some 200 Sitka spruce and cedar stumps found there have been carbon-dated at between 1,700 and 2,000 years old.

Last exposed during the 1983 El Nino, the stumps at Neskowin Beach, along with sunken trees uncovered at other sites along the Oregon coast, are believed to have been part of a great pre-Columbian forest that fell victim to massive, ground-sinking earthquakes.

While not considered an earthquake zone, coastal Oregon is, according to geologists, an area at risk for major quakes every 200 to 1,000 years (the Cascadia Subduction fault line runs 60 to 150 miles offshore). Scientists say the last "super quake" occurred in 1700 and, judging by a Tsunami tidal wave that hit Japan at that time, may have measured as high as 9.0 on the Richter scale.

The revealed tree stumps at Neskowin have been drawing crowds of beach walkers, some who speak of their awe at being among trees that were alive at the time of Jesus. Ocean currents and sand transport are expected to rebury the ancient hardwood forest within a few months.

- David Helvarg


"If you liked El Nino for the last several months, you will love the 21st century if we keep on the path we're on," President Clinton warned last spring in a California speech promoting energy conservation and other efforts to reduce greenhouse gas emissions.

In June Vice President Al Gore held a White House press conference to announce findings by the National Oceanic and Atmospheric Administration that suggested global warming may have also contributed to the appearance of more frequent and more severe El Nino events over the past two decades. "This wetter and warmer winter that we've just experienced gives us a glimpse of what we can expect in a greenhouse-gas, globally warmed world," said NOAA administrator James Baker.

"We've seen unusual changes since 1976 with more El Ninos and the two biggest recorded El Ninos in 1982-83 and 1997-98. This raises questions of whether this is being caused by climate change," agrees Kevin Trenberth, head of the climate analysis section of the National Center for Atmospheric Research in Boulder, Colorado. Trenberth, who also spoke at the White House press conference, explains that "El Ninos take place partly in response to heat buildup, as a way to get heat out of the tropical Pacific . . . the idea is that with more heat going into the atmosphere (from global warming) you'll have more El Nino events."

More than 2,500 of the world's leading scientists, organized as the Intergovernmental Panel on Climate Change (IPCC), have already reported that the burning of carbon-based fossil fuels such as oil and coal has contributed to a 1 degree increase in world temperature over the last century. They project that without drastic corrective action, temperatures around the world will rise another 1.8 to 6.3 degrees over the next century. Along with rising sea levels and more severe storms, they expect extensive loss of forest because of weather-related increases in fires and insect damage, as well as some species' inability to adapt to a rapidly warming climate.

A study by Canadian Forest Service scientists concludes that their northern boreal forests have already lost almost one-fifth of their biomass over the last 20 years because of increases in fire and insect outbreaks. They worry that the reversal of forests from absorber to emitter of carbon dioxide could be contributing to the acceleration of greenhouse gases.

Simple precautionary steps people can take to reduce damage caused by climate change include restoration of historic floodplains in river basins and other flood-prone areas; reductions in roadbuilding, clearcutting, and other erosion-promoting activities on hillsides, streamsides, and other areas at risk for flooding and mudslides; a rapid increase in tree planting, particularly in urban areas where tree shade reduces air-conditioning use and other energy demands; tougher building codes in regions exposed to severe storms, hurricanes, and tornadoes; and a new model for set-back coastal development that respects the protective role played by dunes, mangrove swamps, coastal forests, wetlands, and barrier islands.

At the same time, scientists says it will take between 100 and 200 years for the C[O.sub.2] and other greenhouse gases being pumped into the atmosphere today to cycle out of it. That means the quicker the conversion from oil, coal, and other greenhouse gases to clean, renewable energy sources like sun, wind, biomass, and hydrogen fuel-cells, the less extreme and long-term the climate disruption of the plant will be. But to convert a trillion-dollar-a-year fossil fuel energy industry to a sustainable energy enterprise will take tremendous political will and active engagement by citizens of all countries.

- David Helvarg
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Title Annotation:includes related articles
Author:Helvarg, David
Publication:American Forests
Date:Sep 22, 1998
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