Road in the rainforest of Madagascar. (Photo by R. Butler)
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FUELWOOD/BUILDING MATERIAL
FAO estimates that 40 percent of the world (2.6 billion people) rely on fuelwood or charcoal as their primary source of energy for cooking and heating. Fuelwood consumption has increased 250 percent since 1960 (the world's population only increased by 90 percent since 1960).
The collection of fuelwood and building material from the rainforest remains an important cause of deforestation by settlers. For example, Honduras relies on the burning of fuelwood for 65 percent of the county's energy, while in some African nations the percentage is even higher. In the late 1990s the refugee camps, full of some 750,000 refugees, in eastern Zaire relied heavily on the collection of fuelwood from Virunga National Park, the mountain gorilla reserve. In just a few months over 20,000 acres of park were cleared for fuelwood and building material.
ROAD CONSTRUCTION
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Roads in the Brazilian Amazon. Courtesy of Digital Earth.
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The construction of roads to access logging, oil, and mining sites in the rainforest opens vast stretches of forest to exploitation by landless peasants who are responsible for the majority of rainforest destruction today. Generally these roads are funded by governments and development agencies, but some are also financed by private development interests. One of the most famous projects is the Trans-Amazonian highway in Brazil, which opened up the Roraima state to widespread invasion and deforestation by miners and colonists.
A new road project in South America that will link Amazon outposts in Brazil to Pacific Ocean ports in Peru is of great concern to environmentalists and indigenous-rights groups. The road—known as the "transoceanic highway" -- runs through the state of Madre de Dios in southeastern Peru, an area of extraordinarily diverse rainforest.
Roads in Latin America and other parts of the world are increasingly the result of political pressure from corporate interests, namely loggers and industrial agricultural firms, rather than government-backed poverty alleviation and development efforts. In the Amazon, the power cattle and soy lobby has pushed for infrastructure development so ranchers and farmers can exploit new lands and get their products to market.
HABITAT FRAGMENTATION [Fragmentation news]
Habitat fragmentation is a serious threat to biodiversity and patches of forest worldwide (also see
chapters 9 and 10). As great expanses of forest are increasingly chopped into smaller blocks, edge effects alter the the flora and fauna of forests. Fragmented patches of forest are subject to drying winds that increase the frequency of tree falls. Tree falls tear gaps in the canopy, destroying its function of moderating the humidity, temperature, and heat conditions of the forest floor. These changes affect the species that inhabit the forest patch, usually reducing diversity. Many rare species that dwell in the deep primary forest are unable to cope with the new conditions and are replaced by more common, weedier species. The drier forest conditions also mean that agricultural fires set in the surrounding scrubland and savanna are more likely to burn through the forest patch. During the Indonesian and Brazilian fires of 1997 and 1998, such forest patches went up in smoke at an alarming rate. Fragmented forests also suffer a loss of biomass—up to 36 percent—in the first few years after fragmentation.
South American development plan could destroy the Amazon
New maps reveal the human footprint on Earth
New satellite maps show forest loss and degradation
CLIMATE CHANGE [Climate change news]
Global climate change initiated by global warming is expected to have wide-ranging effects for tropical rainforests
(also see chapter 9).
Changes in weather patterns, rainfall distribution, and temperature will result in the conversion of rainforest into drier forest in some areas and the conversion of other forms of forests into tropical forest. Should sea levels rise, large tracts of rainforest and enormous areas of mangrove forest will be affected. Additionally, though tropical forests and their species have lived through significant climate changes in the past (Pleistocene and Holocene epochs), they have less resilience to climate change in the future due to fragmentation and degradation from human activities. In response to global climate change, communities will need to migrate, an action that will be more difficult because of habitat alteration and fragmentation.
A December 2005 simulation by the National Center for Atmospheric Research projects increased temperatures in the Amazon basin due to the conversion of moisture-producing forest into less-productive pasture and cropland.
Global warming accelerates destruction of the Amazon
40 percent of the Amazon could be grassland by 2050
Global warming will cause local climates to shift and disappear
Global warming could cause catastrophic die-off of the Amazon
Global warming could trigger 8-degree temperature rise in the Amazon
Globalization could save the Amazon rainforest
Expansion of agriculture in the Amazon may impact climate
Amazon drought continues, worst on record
Amazon rainforest locks up 11 years of carbon dioxide emissions
Subtle threats could destroy the Amazon rainforest
Review questions:
- What is an important energy source for rural poor in the tropics?
- Why is forest fragmentation bad for rainforest biodiversity?
- How will climate change effect the distribution of rainforests?
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Continued: Debt
This article was written by Rhett A. Butler [bibliographic citation for this page] and was last updated on the most recent date listed in the column on the right side.
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WEEKLY NEWSLETTER
INTERACT
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Recent news
Tropical ecologist: Australia must follow U.S. and EU in banning illegally logged wood
(02/09/2012) Australia should join the widening effort to stamp out illegal logging, according to testimony given this week by tropical ecologist William Laurance with James Cook University. Presenting before the Australian Senate's rural affairs committee, Laurance argued that the massive environmental and economic costs of illegal logging worldwide should press Australia to tighten regulations against importing illegally logged timber at home.
Rare apes saved in India
(11/30/2011) Two Hoolock gibbons have been successfully translocated from a fragmented forest to Mehao Wildlife Sanctuary in the beginning of a desperate bid to save 18 family groups of India's last apes. Living near the village of Dello in northeastern India, the apes were straining to survive amid heavy deforestation and fragmentation.
Giant rat plays big ecological role in dispersing seeds
(11/16/2011) Rats are rarely thought of as heroes. In fact, in many parts of the world they are despised, while in others they serve largely as food. But, scientists are now discovering that many tropical forest rodents, including rats, serve as heroic seed dispersers, i.e. eating fruits and nuts, and carrying seeds far from the parent tree, giving a chance to a new sapling. While this has been documented with tropical rodents in South America like agoutis and acouchis, a new study in Biotropica documents the first successful seed dispersal by an African rodent: the Kivu giant pouched rat (Cricetomys kivuensis), one of four species of giant African rats.
Atlantic Forest stores less carbon due to drastic fragmentation
(09/26/2011) The Atlantic Forest in Brazil is one of the most fragmented and damaged forests in the world. Currently around 12 percent of the forest survives, with much of it in small fragments, many less than 100 hectares. A new study in mongabay.com's open-access journal Tropical Conservation Science finds that the bloodied nature of the Atlantic Forest impacts its capacity to sequester carbon. The study found that 92 percent of the forest stored only half its potential carbon due to fragmentation and edge-effects, which includes damage due to winds and exposure to drought.
Loving the tapir: pioneering conservation for South America's biggest animal
(09/11/2011) Compared to some of South America's megafauna stand-out species—the jaguar, the anaconda, and the harpy eagle come to mind—the tapir doesn't get a lot of love. This is a shame. For one thing, they're the largest terrestrial animal on the South American continent: pound-for-pound they beat both the jaguar and the llama. For another they play a very significant role in their ecosystem: they disperse seeds, modify habitats, and are periodic prey to big predators. For another, modern tapirs are some of the last survivors of a megafauna family that roamed much of the northern hemisphere, including North America, and only declined during the Pleistocene extinction. Finally, for anyone fortunate enough to have witnessed the often-shy tapir in the wild, one knows there is something mystical and ancient about these admittedly strange-looking beasts.
More news on fragmentation
More rainforest news
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