Week 3

Chapter 3 – Biodiversity and Evolution

Discuss: “You are a defence attorney arguing in court for sparing an undeveloped old-growth tropical rainforest from being cleared and developed. Give your three best arguments for the defence of this ecosystem.”

“Your Honour, old-growth tropical rainforests provide human beings with a large range of plant species, many of which are important for agricultural purposes. Farmers of banana, sugarcane and cocoa are reliant on the cross-breeding of these domesticated plants with their wild tropical rainforest relatives, in order to maintain crop resistance to diseases and pests. In addition, old-growth tropical rainforests provide natural pesticides; in the form of pest-eating insects and plant derived insecticides. The destruction of this old-growth tropical rainforest will leave essential crops venerable to major damage, with consequential adverse affects left to be felt by humans (Ninan, 2006, p. 4).”

“It has been proven beyond reasonable doubt, that tropical rainforests support the greatest diversity of living organisms on Earth, and have the potential to help understand and eliminate currently untreatable diseases (Chivian, 1994). While these old-growth jungles cover only a small part of the planet’s surface; they remain the habitat for up to 90 percent of the world’s entire species (Ninan, 2006, p. 4). Researchers estimate that tropical old-growth rainforests house between five to 50 million different species (Butler, 2006). This exceptional wealth in biodiversity combined with the devastating tropical deforestation rate suggests that many animal and plant species will become extinct, before humans have the chance to study them. If humans develop this untouched tropical rainforest, they run the risk of denying the human species of not only instrumental rainforest values, but possible remedies for currently incurable diseases (Chivian, 1994; Miller & Spoolman, 2009, p. 99.)”

“In closing, the consequences of clearing tropical old-growth rainforests can have a detrimental effect on the earth’s climate. The warm humid air provided by these forests provide an even ecological foundation by creating warm, moist air that in turn generates the release of great quantities of energy into the atmosphere, and this process directly affects climate. Additionally, tropical old-growth rainforests are naturally a “carbon sink”; however the destruction of these environments turns these sinks into a source. As deforestation occurs, carbon dioxide emissions are released which then in turn further depletes the ozone layer. Researchers have warned that if humans obliterate this vast tropical old-growth rainforest, they will undoubtedly and detrimentally affect this important energy transfer process that ensures the stability of their own climate (Bunyard, 1999).”

References:

Bunyard, P. (1999). Eradicating the Amazon rainforests will wreak havoc on climate. The Ecologist,(29)2, 81-84.
Butler, R. (2006). Consequences of deforestation. Retrieved from http://rainforests.mongabay.com/0901.htm

Chivian, E. (1994). The ultimate preventive medicine. Technology Review, 97(8), 34.
Miller, G. T., & Spoolman, S. E. (2009). Sustaining the earth. (9th ed.). Belmont, CA: Brookes/Cole
Ninan, K. N., Jyothis, S., Babu, P., & Ramakrishnappa, V. (2007). The economics of biodiversity conservation: valuation in tropical forest ecosystems. London, UK: Earthscan