Threats to tropical forest ecosystems (local and global)

A Damp Rainforest Extinction is a natural event and, from a geological perspective, routine. We now know that most species that have ever lived have gone extinct. The average rate over the past 200 million years is 1-2 species per million species present per year. The average duration of a species is 1-10 million years (based on the last 200 million years). There have also been several episodes of mass extinction. In the modern era, due to human actions, species and ecosystems are threatened with destruction to an extent rarely seen in the Earth's history. Industrial society has tended to see forests as free sources of valuable materials or as needless woods, occupying land and getting 'in the way' of development. As a result, threats to tropical forests exist at a range of scales: local - national - international.

Local Threats

An estimated 60% of tropical deforestation is caused by subsistence activities by people who use the rainforest's resources for their survival. Activities include:

Slash and Burn techniques for forest clearance. This is achieved by clearing shrubbery and forest trees, leaving areas to dry and then burning it. The land is planted with crops like bananas, palms, manioc, maize, or rice. After a year or two productivity of the soil declines, and transient farmers move on.
Wood gathered from forests is the major fuel in many countries.
Introduction of domesticated animals by local land users can devastate local wild animal populations.
Hunting to support subsistence agriculture is another major threat to wildlife at a local level.

National Threats

Government policies and politics affect all levels of development, from local initiatives to international relations. All of these affect the tropical forest ecosystem.
Governments encourage colonization of rainforest land. This land is seen as unproductive as it does not contribute to GNP. Tax incentives and building of large-scale infrastructure also drives colonisation.
Resettlement programmes are another method of colonising the rainforest frontier.
Increased levels of agriculture such as cash crops and cattle ranching put pressure on rainforest ecosystems due to land requirements.
Legal logging practises. For more information visit: The Rainforest Information Center

International Threats

Most threats on an international level are driven by economic forces.

Oil extraction. Like mining this process can devastate an area through the destruction of the forest, increased levels of infrastructure and workers, and pollution resulting from the oil extraction process.
Mining (strip and open cast mining are the two most destructive types). Apart from the simple destruction of the forest above and around the mine, the mining process releases harmful toxins, like mercury and cyanide into local waterways, polluting the waters and surrounding lands.
Cash crop agriculture has driven poorer people in to marginal land forcing many to cultivate forested areas.
Ranching. Increased demands for cheap meat products in developing countries have driven market forces in this area.
Logging. Continual demand for timber drives this destructive force. Short term logging concessions and the inability to control logging activities increase the rate of forest loss.
Trade in endangered species is a multi-million pound economy and is steadily increasing with Bushmeat being one of the most significant trade products.

Edward O Wilson, an eminent biologist, discusses the loss of biodiversity in the book The Diversity of Life. Here he highlights the gravity of the situation.

" The worst thing that can happen, will happen, is not energy depletion, economic collapse, limited nuclear war, or conquest by a totalitarian government. As terrible as these catastrophes would be for us, they can be repaired within a few generations. The one process ongoing in the 1980's that will take millions of years to correct is the loss of genetic and species diversity by the destruction of natural habitats. This is the folly that our descendants are least likely to forgive us." The Diversity of Life

For more details on threats, see: World Rainforest Movement or The Rainforest Information Center