Transformation of the Bioshpere: Deforestation
Today, at least 16 million hectares of forests are lost each year to timber harvesting and the conversion of forests to farmland. See the dramatic decline of the Earth's original forest cover.
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This presentation, available online as a printable PDF, discusses the global effects of deforestation. It contains the following three pages:
- an overview of the reasons people have cut forests and how the direct destruction of forests is the primary reason for today's massive extinction of species
- a world map that shows the global forest cover 8,000 years ago
- a world map that shows the significantly smaller remaining frontier forests as of 1997—intact natural forest ecosystems that are relatively undisturbed and large enough to maintain all of their biodiversity.
Less than 1 period
Supplement a study of biodiversity or ecology with an activity drawn from this online presentation.
- After explaining the difference between finite and infinite resources, ask students which one they think forests are.
- Send them to the online presentation, or distribute printed copies of it for them to review.
- Have students research the decline of forests in their state (or a nearby state for non-forested regions) over the past 100 years.
- Using their research findings, have students prepare two comparison maps (one now, one 100 years ago).