Forest razed Jan 98 New Scientist
Burning and logging destroyed more rainforest in Brazil in 1995 than in any previous year, according to figures released last week by the country's, National Space Research Institute. The area lost, 29 059 square kilometres, was almost twice the area deforested in 1994. High rainfall reduced the damage in 1996 to 18,161 square kilometres, and the Brazilian government says it expects the 1997 figure to be lower still, at around 13,000 square kilometres. But observers are sceptical of the claim because of the large number of fires spotted in the Brazilian Amazon by the US's NOAA-12 satellite earlier this year (This Week, 11 October 1997, p 10).
Drought increases Burning in Indonesia and the Amazon New Scientist 11 Oct 97
THE heat and drought that helped trigger Indonesia's disastrous forest fires in recent weeks are wreaking havoc in South America, according to satellite data. Fires are raging through the Brazilian rainforest faster than in the late 1980s, when the burning made the region the focus of intemational environmental concern. The Brazilian Amazon and Indonesia contain the world's two largest surviving regions of rainforest. The US government's NOAA-12 satellite spotted more than 24,000 fires in the Brazilian Amazon between early August and mid-September, the height of the burning season. This is a 28 per cent increase on the previous year, the satellite's first year on fire watch. The blaze has also spread to neighbouring Colombia. The fires, most of which are started by farmers, show up as temperature anomalies in night time data from the satellite's Advanced Very-High Resolution Radiometers. Stephan Schwartz man, an anthropologist from the Environmental Defense Fund in Washington DC who analysed the data, says the satellite will not spot all fires-some are too small or are extinguished before nightfall. Even so, NOAA-12 identified an aver age of 600 every night during a watch that lasted over 40 days. Numbers of fires do not corre spond precisely with deforestation rates. Many fires are lit to maintain cattle pastures already cleared from the forest. And much burning of virgin forest takes place unseen beneath the canopy. But Schwartzman says that "increased urning strongly suggests that deforestaion rates continue to rise". He estimates at the current total deforestation rate is robably higher than at its previous peak n 1988, standing at around 20 000 square ometres a year. The hot, dry conditions in the tropics that promote forest fires have been caused y the El Nino climate anomaly, which is t its most intense and disruptive since cords began in 1950. - Fred Pearce
Rain Forest burns in the Amazon basin. Unusually dry conditions caused large conflagrations that blanketed much of Brazil during this past year's fire season.
Smoke Alarm Scientific American Dec 97
This past September, choking smoke from unchecked forest fires blanketed millions of square miles in southeast Asia. But that was not the only part of the world where burning of vegetation caused widespread haze. In the Amazon Basin the 1997 burning season produced a "very thick" pall that extended far beyond the region where smoke has spread in recent years, according to Paulo Artaxo of the University of SAO Paulo. Forrest M. Mims Ill, an independent scientist who runs the Sun Photometer Atmospheric Network and is based in Seguin, Tex., says smoke may have covered half of Brazil when he was in the country in August. The blockage of sunlight, Mims believes, may encourage the spread of harmful bacteria and viruses. Many of the fires in Brazil are set to clear the rain forest, although some take hold accidentally when farmers burn pasture, Artaxo states. One reason the 1997 fires were so extensive is that forests were very dry, a consequence of El Nino, a periodic climatic oscillation, which is quite strong this year. The health effects of breathing smog from July to October each year are unknown. Yet the clues seem ominous: the most polluted U.S. cities, for example, generally have higher death rates than others. And Mims reports that physicians in the remote city of Alta Floresta in west-central Brazil concluded that half the local population was suffering from respiratory illness. In Manaus, some 600 miles northwest, there were "very significant" increases in the number of patients hospitalized with bronchitis, Artaxo notes. Mims suggests that one way smog might cause illness is by absorbing ultraviolet light, specifically the band knovm as UV-B, because it is well known to kill bacteria and viruses. Mims found that levels of UV-B in Alta Floresta during one of the smokiest days of his stay were less than a tenth of levels on a clear day. Sometimes measured UV-B reached zero. Light that plants use for photosynthesis was reduced by more than 50 percent on some days. Mims also found that on reduced UV-B days, airborne bacteria that lack internal pigmentation became more conunon relative to pigmented types. Because most pathogens are nonpigmented (for reasons that are unclear), Mims thinks that bacteria and viruses could become more of a health threat in hazy conditions. Further research will be needed to evaluate Mims's findings, which he was expecting to submit for formal publication soon. Yet research on the Amazon part is not proceeding as quickly as many scientists would like. Although the capabilities of satellites are improving, monitoring of biomass, burning "is not adequate," says Brent N.' Holben of the National Aeronautics and Space Administration Goddard Space Flight Center. Bureaucratic delays appear to be part of the problem. Two years ago NASA told Holben to remove from Brazil a network of ground-based instruments that could validate satellite measurements, because officials had concluded that Brazil and the U.S. needed a formal agreement covering the network. No agreement has been forthcoming, alid Holben is still waiting to take his instruments back to Brazil. -Tim Beardsley in Washington, D. C.
NZ Herald Mar 28 98 Carbon-dating has found at least four huge burnoffs in the last 2000 years in the Amazon region, the last about 400 years ago, but this year's fires in Roraima fuelled by the most severe drought in 30 years are the worst in recent history. Roraima is a microcosm for the entire Amazon because it contains all types of vegetation endemic to the region in a realtively small area. The fires are not simply and act of nature or God. Settlers streaming into the region and increased logging are making the forest more vulnerable to the effects of drought in the El Nino periods. 5200 sq km are lost every year to slash and burn agriculture. 12% has been currently felled. Even selective logging opens gaps which can accelerate drying.
Species Diversity Loss Catastrophic in Indonesian Fires June 98 MZ Herald
SINGAPORE - "Where you used to hear the cicadas, now it's deathly quiet. There is no sound." Biologist , Willie Smits is describing a research forest. He has spent 18 years studying plants and animals there. But over the past year, most of it has been toasted. Flres destroyed all but 20ha of the 3500ha Wanariset forest, in Indonesia's Kalimantan province. Rains in April brought a respite, although Smits believes it will be a temporary one as the dry season looms. He worries that the region's rich biodiversity has been lost forever. "It probably won't come back," he said. "In this area we have discovered many, many new species - climbers, trees, insects.' Fires - blamed variously on the El Nino weather effect, slash-and-burn agriculture or land clearance for plantations - have swept through forests in Indonesia, the Pbilippines, Malaysia, Thailand and Vietnam. The fires occurred in a region of tropical rainforests, one of the planet's last great reserves of biodiversity. Many destroyed secondary forests - cleared land which has reverted to forest. But they also spread to forests wldch have never been felled. Experts put the area of burned forests in Indonesia at more than 5 million ha. Before the fires more than 180 species of butterflies, varying in colour from metallic green to blue, were known from the area. Since the fires were put out only four have been rediscovered. A herbarium in the area also described several new species of rattan, conunercially important for making furniture. Although Smits has seen other fires in his time in Indonesia, these were the most destructive. And he expects more. The rainfall pattern is going bizarre and that is going to have an enormous impact on biodiversity.- - REUTERS
Brazil Acts on the Incredible Shrinking Rainforest New Scientist 3 Aug 96
Brazil decreed tough new restrictions whose effect remains to be established in response to satellite information indicating a 34% increase from 11000 sq kilometres/year in 1991 to 14900 between 1992 and 1994. That's an incredible explosion of deforestation says Philip Fearnside at the National Inst. of Amazon Research in Manaus. President Cardoso declared a two year suspension on new mahogany and virola harvestingand increased from 50 to 80% the amount of land ranchers and farmers must leave on their property. Fearnside cautions that these restrictions may not work because Brazil's environmental laws are regularly flouted.
It should be noted that Brazil has massive inequalities in ownership of existing farmlands with a very small number of rich landowners holding the vast majority of land. Most has occurred in Matto Grosso where farmers who are meant to clear 50% cleared 100%.
Surinam secures 10% May 98
Surinam will turn 1.6 million hectares of Amazon rainforest into a nature preserve protecting the virgin jungle from the international logging firms. The land involved is almost 10% of the territory.
Invasion of Brazilian National Park Feb 98
Hundreds of farmers have invaded one of Brazil's most famous national parks and illegally built a road with the aid of local politicians, says the Govemment's environmental agency, Ibama The road cuts through the middle of the Iguacu National Park, a designated Unesco world heritage and home to the monumental Iguacu Falls that straddle the Brazilian-Argentine border. "This was a dirt path which, - until the invasion, was practically, overgrown by forest," said the Ibama director of ecosystems, Ricardo Soavinski. The agency had been in discussions with local residents about allowing use of the path for light traffic and tourism when the first invasion occurred in July, he said. Local farmers cut down trees to widen the road and installed a barge system to help vehicles cross a river. A court ordered the intruders out but in January there was a second invasion. The Government is considering evicting the locals by force after reports of heavy trucks carrying agrochemicals going into the park. Iguacu National Park covers 185,000ha, and 55,000ha of adjacent parkland lie across the border in Argentina. "This is one of the world's richest ecosystems in terms of biodiversity Mr. Soavinski said. Local politicians are helping with the invasion to try to win votes in the mainly rural region, the heartland of Parana state is soy-bean growing industry. Brazil is due to go to the polls next October. "We have made an enourmous effort to resolve this in a pacifist manner and it hasn't worked. We are going to have to take action to remove them.
Rainmaker: At least half the rain falling on the tropical forest canopy evaporates.
Rainforest Destruction Causes Drought Crisis - New Scientist 18 Jan 1997
DROUGHTS in West Africa over the past 20 years may have been caused by the destruction of rainforests in countries such as Nigeria, Ghana and Cote d'Ivoire, according to a new study. Further deforestation in the region "could cause the complete collapse of the West African monsoon", says Xinyu Zheng of the Centre for Global Change Science at the Massachusetts Institute of Technology. Rainforests need high rainfall to grow. But they also help to generate rainfall elsewhere. Half or more of the rain falling on the forest quickly evaporates from the forest canopy, providing moisture in the air to form clouds that produce rainfall further downwind. In this way, West African coastal rainforests, which receive copious amounts of rain from winds coming off the Atlantic Ocean, have helped to maintain rainfall in the drier lands of the interior. At the beginning of this century, the West African coastal rainforests covered around 500 000 square kilometres. Since then, up to 90 per cent have disappeared to make way for farms and other kinds of human activity such as mining. Overgrazing, expansion of arable land and the substantial growth of the timber industry are the main culprits. As the forests are cut down, more of the rain falling on coastal regions percolates into soils or flows directly to the sea. Evaporation is reduced, which affects rainfall in drought-prone countries of the interior such as Mali and Niger. Several studies have predicted that deforestation of the Amazon basin will have a similar impact in Brazil, but Zheng and coauthor Elfatih Eltahir, also of MIT, say that the effect may already be happening in West Africa. They point out that the proportion of total forest cover that has been cleared is much greater in West Africa than in the Amazon, In Geophysical Research Letters this week (p 155), the researchers report on a statistical model of the hydrological cycle of the West African monsoon that takes into account such features as energy flows, rainfall and evaporation in the coastal region, and condensation as new clouds form inland. it also predicts the position of the Inter-Tropical Convergence Zone (ITCZ), the permanent weather front which is the source of most of the rain on the coast of West Africa. The model confirms an old theory, first developed 20 years ago by MIT's Jule Charney, that the loss of vegetation on the edge of the Sahara Desert in the West African interior could reduce rainfall. But the authors say this effect is much smaller than that of coastal deforestation, which until now has been virtually unresearched. The model predicts that as forests are lost, the coastal rainfall will no longer be recycled to create rain inland. And worse, the ITCZ, which normally moves across the land during the summer monsoon, "stays over the ocean". The "worst possible scenario for tropical deforestation in West Africa", the authors say, would see "all the forests replaced by savanna". This, according to Zheng's model, "could cause the collapse of the monsoon system". So far that has not happened, and the authors admit that their model is fairly crude. But they point out that since 1970, rainfall over the whole of West Africa has been lower than before, apparently confirmin their redictions.
A rotten prospect for the tropics New Scientist Dec 97
GLOBAL warming will cause a massive "dying-off " of tropical vegetation after 2050, warns a new study. The devastation will mean that the 2 billion tonnes of carbon that are currently soaked up by rainforests every year will remain in the atmosphere, further accelerating global warming. The analysis is the most sophisticated study yet carried out into the impact of climate change on vegetation. lt is far more pessimistic than recent forecasts by the UN's Intergovernmental Panel on Climate Change. The research, unveiled in Kyoto this week, was undertaken by Melvin Cannell and his colleagues at the Institute Of Terrestrial Ecology at Edinburgh. lt simulates the effect of predicted climate change on the carbon, nitrogen and water cycles that support vegetation. At first, the news will be good. As emissions from industry continue to rise, the extra C02 in the atmosphere will fertilise vegetation and speed growth. Hence the amount of C02 pollution absorbed by the world's land vegetation will initially rise from the current 2 billion tonnes a year-roughly a third of human emissions from burning fossil fuels-to around 2-6 billion tonnes by 2050. But after that, warming of up to 8 oC in parts of the tropics will lead to higher evaporation rates, lower rainfall and eventually the collapse of tropical ecosystems, with a "major loss of biodiversity", say the researchers. "Tropical grasslands will shrink from 8 per cent to 1 per cent of the global land area ... tropical forests will change to savanna, grassland or even desert." As a result, the amount of carbon that the world's vegetation absorbs each year will decrease dramatically. By about 2080, C02 UP take will be negative, says Cannell, with rotting vegetation emitting more carbon than the re maining living trees absorb. And this is despite a continuing increase in growth in temperate and northern forests in Europe, North America r 2100 and Russia, where biomass could increase by Source. Connell 1997 70 per cent between now and 2080.
Life on the Edge: Small Areas
of Rainforest May Not be Worth Saving
New Scientist 9 May 98
Washington DC 1998 CONSERVATION in many parts of the tropics relies on preserving fragments of forest left over after farmers have cleared the rest. But such efforts may be wasted on areas of 100 hectares or less, which new research suggests are too small to remain as self-regenerating ecosystems. Julieta Benitez-Malvido of the National University of Mexico in Morelia studied 11 fragments of forest ranging in size from 1 to 100 hectares near Manaus, Brazil. She found that the density of shade-tolerant seedlings-which represent the majority of trees-decreases dramatically towards the forest edge, and is up to 40 per cent less in the corners of a fragment than in the centre. She concludes that below a certain size, rainforest segments cannot contain enough seedlings to fully regenerate the plant species within them (Conservation Biology, vol 12, p 380). "When I started the project, I thought seedling density would be higher closer to forest edges, as the edges are lighter," says Benitez-Malvido. In fact, the opposite was true. One of the key factors was the change in climate within the forest, with a hotter, drier enk,iron- ment near the edges prevent- ing germination of shade-tolerant species. Thev were also hindered by having to compete with light-tolerant species that have higher growth rates. The reduced number of ani- mal species in small forest sections is also an important factor. Around 80 per cent of tropical trees are pollinated by animals, which also help to disperse the seeds and fruits. Fig trees, for example, are pol- linated bv wasps and their seeds dispersed bv bats, rodents, monkeys, iguanas and ants. Fewer primates, birds and other animals means there is less "seed rain"- seeds dispersed in faeces. Benitez-Malvido concludes that even 100-hectare fragments do not nurture enough seedlings to be self-sustaining. But she admits that preserving fragments of 100 hectares or less may be the only option in some areas. "At least these fragments can serve as germplasm pools for many animals and plants," she says. "We need to learn how to manage these patches to preserve them, and if possible to increase their area." Charlie Pye-Smith
researchers back on level terms with the humble carpenter. Andy Coghlan
Money to Burn? New Scientist 16 May 98 23
TO LOSE one species may be regarded as a misfortune. To lose any more of the remaining 3214 rare and endangered plant species in the US could mean throwing away a fortune. In the first study to put a price on this vanishing vegetation, Brien Meilleur of the Missouri Botanical Garden in St Louis and Oliver Phillips of the University of Leeds estimate that rare plants in the US could be worth billions of dollars a year- "The public tends to think we are losing oddities that might be interesting but don't have much impact on society," says Phillips. "These figures contradict that." Phillips and Meilleur compiled a comprehensive database of plants used for foods, animal fodder, timber, medicine and other products. They then looked at which of the US rarities belonged to the same genus as one of these useful plants- a good indicator of their economic potential. Close relatives of medicinal plants, for example, are likely to produce similar, perhaps more potent, versions of the active ingredient. And wild relatives of crop plants are a repository of genes that could be used to improve today's varieties. The survey revealed that 80 per cent of America's threatened plants belong to a genus that includes at least one, and often many, useful species (Economic Botany, vol 52, p 57). "Biotechnology makes it easier to move genes around, so wild relatives could make more of a contribution to the cultivated ones in future," says Phillips. Some of the wild species in the US have already shown their potential. American grape vines saved Europe's wine industry from the ravages of the root-sucking phyiloxera louse late last century. The hybrid sunflower grown throughout the US is a product of breeding with wild Helianthus- species, which have given the crop its improved yields and resistance to fungi. Yet 12 wild varieties of Helianthus are in trouble in the southern US. While putting a precise value on the economic potential of endangered plants is almost impossible, Phillips and Meilleur made their estimate from the sales of crops with rare wild relatives - assuming that the rarities could be just as valuable. This gave them a figure of $9 billion a year for the US market alone. "But putting a dollar figure on plants is less important than demonstrating how many of them have the potential to be important economically," says Meilleur. "Species should not be allowed to go extinct anyway," says Mark Collins of the World Conservation Monitoring Centre in Cambridge. "But the economic argument should help to persuade those who hold sway over resources for conservation that matters should be taken more seriously." Stephanie Pain, St Louis
Ragged Edge New Scientist 22 Aug 98 13
THE effect on global warming of clearing rainforests may have been seriously underestimated. A team from Brazil has found that carbon emissions from the felling of tropical forests are generally 7 per cent higher than previously thought, and as much as 42 per cent higher in some places. Recent estimates suggest that deforestation worldwide releases about 2 billion tonnes of carbon into the atmosphere every year through burning and decomposition, a large proportion of which comes from the tropics. But according to William Laurance at the National Institute for Research in the Amazon in Manaus, Brazil, the figures do not take into account the extra carbon dioxide produced by the fragments of forests left after clearing. In an 18-year study of 66 forest fragments, published in Science last November (vol 278, p 1117), Laurance and his team found that the fringes of forests-within 100 metres of the edge-lose significantly more vegetation than the inner areas because they are exposed to higher winds and other extremes of climate. The resulting decomposition emits considerable quantities of carbon dioxide and methane, two major greenhouse gases. The loss of trees also means that there is less biological matter capable of absorbing carbon dioxide from the atmosphere during growth. Now, in a follow-up project, soon to be published in Forest Ecology and Management, the researchers have calculated the amount of carbon dioxide emitted by tropical forest fragments. They simulated three patterns of forest clearing: the small-farmer settlement schemes of southem Amazonia, the large cattle-ranching clearances typical of eastem Amazonia, and a random scenario imitating unplanned forest loss. The first two account for most forest clearance in the region. In each case, the team tested various levels of clearance, from 5 to 95 per cent of the land area. At every level, the random and the small farmer scenarios suffered the highest carbon losses between two and five times more than for the large cattle ranching models-because they led to greater fragmentation. The randomly cleared landscapes, in which irregular edges were common, were especially prone to veg etation loss, even at very low levels of clearance. The team calculates that annual carbon emissions from fragmentation of forests are between 3 and 15.6 million tonnes in the Brazilian Amazon and between 22 and 149 million tonnes for all tropical forests at present rates of clearance. This suggests that current estimates for carbon emissions from the felling of tropical forests are up to 7 per cent too low, and as much as 42 per cent too low in some areas, says Laurance. "This prediction seems rather modest until one realises that this is the equivalent of clearing and burning an additional 150 000 to I million hectares of rainforest each year." If anything, he says, the figures underestimate the problem: the experimental plots were surrounded by regrowth forest which provided some protection from wind. Fragments surrounded by cattle pasture and crops would be fully exposed. Laurance says that goverrunents should encourage patterns of forest clears ance that minimise fragmentation. Charlie Pye-Smith
Rotting Forests Come up Tops 1 Nov 97 New Scientist
PARASITIC fungi are helping to nurse ailing forest ecosystems back to health. By injecting the fungi into the heartwood of healthy trees, American biologists hope to recreate habitats for woodpeckers and other creatures that have been destroyed by decades of "salvage logging". Sick and dying trees provide shelter for birds, mammals and reptiles. But in many forests across the US, loggers harvest tree showing the first signs of fungal infection to produce pulp for paper maker Although they plant replacements, thes are usually harvested before they start to rot "In some places there aren't any sick trees left," says Catherine Parks, a plany pathologist at the Pacific Northwest Research Station in LeGrande, Oregon 'We needed something to jump-start the process that creates this habitat." In the past, forest managers had tried blasting off the tops of trees with explosive charges or burning their roots. But animals didn't seem to find artificially damage trees so attractive, and the trees were so severely weakened that they could only provide shelter for a few years. So Parks and her colleagues decided see if they could accelerate the natural process of fungal infection in a group western larch trees in Oregon's Wine Natural Forest. They first established th the heartwood of western larch trees normally rotted by the fungi Phellinus pi nd Fomitopsis pinicola. They then took dowels soaked in liquid cultures of the fungi and inserted them into holes filled into the centre of trees. In an initial trial, the fungi took hold in one of 60 trees injected two years Ten are already hosting woodpeckers, is about twice the nesting rate seen blasted trees, says Todd Forbes of the US. Forest Service in Chemult, Oregon, who worked on the trial. And while the fungi eat at the trees' hearts, they don't seem to impede growth-which means that the trees should provide shelter for forest creatures for decades. Parks argues that the new technique should also appeal to loggers, because the dowel-infected trees are less likely to fall 'The trees should provide shelter for forest creatures for decades unexpectedly than those that have been blasted or burnt. Forest managers are already showing interest, she says. Spurred by their success, the researchers have now launched a trial of 5000 trees, including lodgepole pine, ponderosa pine, red cedar and Douglas fir, in 16 forests throughout the westem US. Philip Cohen, San Francisco