Global Deforestation [pic]
It is impossible to overstate the importance of humankind's clearing of the forests. The transformation of forested lands by human actions represents one of the great forces in global environmental change and one of the great drivers of biodiversity loss. The impact of people has been and continues to be profound. Forests are cleared, degraded and fragmented by timber harvest, conversion to agriculture, road-building, human-caused fire, and in myriad other ways. The effort to use and subdue the forest has been a constant theme in the transformation of the earth, in many societies, in many lands, and at most times. Deforestation has important implications for life on this planet.
Just think, originally, almost half of the United States, three-quarters of Canada, almost all of Europe, the plains of the Levant, and much of the rest of the world were forested. The forests have been mostly removed for fuel, building materials and to clear land for farming. The clearing of the forests has been one of the most historic and prodigious feats of humanity.
|[pic] | |Area of Forest Ecosystems (World total:~ 34 million km2) |
About one half of the forests that covered the Earth are gone. Each year, another 16 million hectares disappear. The World Resources Institute estimates that only about 22% of the world's (old growth) original forest cover remains "intact" - most of this is in three large areas: the Canadian and Alaskan boreal forest, the boreal forest of Russia, and the tropical forest of the northwestern Amazon Basin and the Guyana Shield (Guyana, Suriname, Venezuela, Columbia, etc.)
Today, forests cover more than one quarter of the world's total land area, excluding polar regions. Slightly more than 50% of the forests are found in the tropics and the rest are temperate and boreal (coniferous northern forest) zones.
Seven countries (Russia, Brazil, Canada, the United States, China, Indonesia, and the Democratic Republic of Congo (formerly Zaire) account for more than 60% of the total.
For millennia, humankind has influenced the forests, although much of the impact has been relatively minor. Today, the impact is enormous. Deforestation is expanding and accelerating into the remaining areas of undisturbed forest, and the quality of the remaining forests is declining. Today we examine global patterns in deforestation, assess the human and ecological costs of forest loss, and discuss some of the steps that can help to rectify this alarming situation.
|Frontier Forests of the World | |[pic] | |Red = Frontier Forests, 8,000 years ago | |Green = Frontier Forests Today |
Until quite recently, most of the deforestation occurred in Europe, North Africa, and the Middle East. By the beginning of this century, these regions had been mostly converted from the original cover. Now, deforestation in these regions has stabilized and regrowth is occurring (though second growth forests have quite different character, see below). In the last few decades, the vast majority of deforestation has occurred in the tropics - and the pace still accelerates. The removal of tropical forests in Latin America is proceeding at a pace of about 2% per year. In Africa, the pace is about 0.8% per year and in Asia it is 2% per year.
|Area of primary forests in the United States (lower 48) | |(around 1620, top; and 1850 middle; 1920, bottom) | |[pic]...
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