Rates of deforestation vary from one Amazon country to another, mostly because the factors that drive this process also vary across the region. In Brazil for instance, most clearing is carried out in large and middle-sized ranches for cattle pasture, whereas the role of small farmers clearing for agriculture is relatively more prevalent in other countries3
Deforestation is particularly marked in areas adjacent to urban centres, roads and rivers. But even remote areas that are considered void of human activity are showing signs of human pressures, especially where mahogany and gold are found.4
Some deforestation, when carried out in private properties, can be legal. According to the Brazilian Forestry Code (a federal law), 20% of rainforest in each property can be cleared under a license provided by environmental agencies.
What are the impacts of deforestation?
It is impossible to draw a comprehensive list of everything we stand to lose from deforestation. But here are some of the main aspects:
Loss of biodiversity:
Species lose their habitat, or can no longer subsist in the small fragments of forests that are left. Populations dwindle, and eventually some can become extinct. Because of the high degree of endemism, or presence of species that are only found within a specific geographical range, even localized deforestation can result in loss of species.
New highways that provide access to settlers and loggers into the heart of the Amazon Basin are causing widespread fragmentation of rainforests. These fragmented landscapes are affected in species structure, composition and microclimate, and are more vulnerable to droughts and fires - alterations that negatively affect a wide variety of animal species.5
Modified global climate:
The forests’ ability to absorb the pollutant carbon dioxide (CO2) is reduced. At the same time, there is an increased presence of CO2 released from the burning trees.
Loss of water cycling:
Deforestation reduces the critical water cycling services provided by trees. In Brazil, some of the water vapour that emanates from forests will be transported by wind to its Central-South region, where most of the country's agriculture is located. Brazil's annual harvest has a gross value of about US$65 billion, and the dependence of even a small fraction of this on rainfall from Amazonian water vapour corresponds to a substantial value for the country. When rainfall reduction is added to the natural variability that characterizes rainfall in the region, the resulting droughts may lead to major environmental impacts. Fires already occur in areas disturbed by logging.6
With reduced forests, people are less able to benefit from the natural resources these ecosystems provide. This can lead to increased poverty and in cases, people may need to move in order to find forests which can sustain them.
The outlook for Amazon deforestation
The demand for land that is currently causing tropical forests to be burned is expected to remain high, sustaining the continued release of carbon from burning trees into the atmosphere.
If droughts, temperatures and El Niño events increase in frequency and severity - as seems to have been the case over the past 200 years - then the amount of carbon emissions from the tropics could rise rapidly in the future, creating a dangerous feedback loop via the impacts of deforestation.7
1 Kaimowitz et al. 2004. Hamburger Connection Fuels Amazon Destruction: Cattle ranching and deforestation in Brazil's Amazon. Centre for International Forestry Research (CIFOR). 10 pp.
2 International Herald Tribune. Sunday, November 20, 2005. China's global push for resources makes waves in Amazon basin.
3 Goudie (Ed.) 2001. Encyclopedia of Global Change. Environmental Change and Human Society
4 Barreto et al. 2005. Human Pressure in the Brazilian Amazon. IMAZON.
5 Laurance et al. 2000. Forest loss and fragmentation in the Amazon: implications for wildlife conservation. Oryx, 34 (1), pp. 39-45
6 Goudie (Ed.) 2001. Encyclopedia of Global Change. Environmental Change and Human Society
7 Lewis, S.L. 2005. Tropical Forests and Atmospheric Carbon Dioxide: Current Knowledge & Potential Future Scenarios. Avoiding Dangerous Climate Change Symposium, Exeter, 1-3 February 2005.