Deforestation and Biodiversity

Deforestation, defined by biologist Charles Southwick as "the destruction of forests; may involve clear-cutting or selective logging" (p. 365), is a predominantly human-driven process that is dramatically altering ecosystems worldwide. "Clear-cutting" involves the indiscriminant removal of every single plant and tree species from within a selected area. The other major process of deforestation, "selective logging," focuses removal efforts on only specific, predetermined tree species within a chosen area. The statistics gathered about human deforestation over time are considerable, and they can be somewhat controversial. Depending on the source and the location selected, the magnitude of deforestation varies. Southwick estimates that, approximately 10,000 years ago, 6.2 billion hectares (23.9 million square miles) of forest existed on earth (p. 117). That figure is equivalent to 45.5% of the earth's total land. He further estimates that, by 1990, this amount had declined 30%, with only 4.3 billion hectares of forest remaining (p. 117). Southwick also acknowledges other estimates that place the total amount of deforestation between 50% and 75% (p. 117). NASA has similar deforestation statistics that confirm these trends. According to their website, 16.5% of the Brazilian Amazon forests have been destroyed. They also note similar magnitudes of deforestation in Southeast Asia (Cambodia, Indonesia, Laos, Malaysia, Myanmar, Thailand, and Vietnam), despite the significantly smaller total area of forest within these countries. These grim figures are somewhat tempered by the NASA finding that, over the past ten years, the deforestation rate has declined from 6,200 square miles per year to 4,800 square miles per year. Though this trend is n...

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...later time. Though it is simply impossible to know what the ultimate effects will be on our long term survival as a species, it is important to bear in mind that, once a species has been eliminated through extinction, it cannot be brought back. So, for the overall health of our rainforests, their biodiversity, and the limitless potential contained therein, it is crucial for us, as humans, to make as honest an effort as possible at their preservation.

References

Southwick, Charles H. Global Ecology in Human Perspective. Oxford University Press: New York, 1996.

Vandermeer, J. & Perfecto, I. Breakfast of Biodiversity. The Institute for Food and Development Policy: Oakland, CA, 1995.

Websites

NASA

http://earthobservatory.nasa.gov/Library/Deforestation/deforestation_3.html

National Institute of Health

http://ehp.niehs.nih.gov/docs/1997/105-11/focus-abs.html