WHAT IS    DEFORESTATION Deforestation is the permanent destruction ofindigenous forests and woodlands. The term does no...
DEFORESTATION      CONTINUES Deforestation has resulted in the reduction ofindigenous forests to four-fifths of their pre...
WHAT ARE       FORESTS AND       WOODLANDS? In a forest the crowns of individual trees touchto form a single canopy. In ...
HOW DOES   DEFORESTATION      HAPPEN Deforestation is brought about by the following: * Conversion of forests and woodla...
HOW DOES IT           HAPPEN          CONTINUES Commercial logging (which supplies the worldmarket with woods such as mer...
WHY To compound the problem, the poor soils of thehumid tropics do not support agriculture for long. Thus people are oft...
CONSEQUENCES OF     D E F O R E S TA T I O N* A LT E R A T I O N O F LO C A L A N D G LO BA L C L I M A T E S  T H RO U G ...
CONSEQUENCES OF  DEFORESTATION    CONTINUES b) The water cycle. Trees draw ground water upthrough their roots and release...
CONSEQUENCES OF  DEFORESTATION    CONTINUES       * Soil erosion With the loss of a protective cover of vegetation more s...
LIST OF            REFERENCES THE GAIA ATLAS OF PLANET MANAGEMENT. N Myers(ed.). Pan Books, London, 1985. BEHIND THE WOO...
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THESE NOTES ARE ABOUT DEFORESTATION, ITS IMPACT AND ITS RESULTS IN SOUTH AFRICA AND IN THE WORLD

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  1. 1. WHAT IS DEFORESTATION Deforestation is the permanent destruction ofindigenous forests and woodlands. The term does not include the removal ofindustrial forests such as plantations of gums orpines.
  2. 2. DEFORESTATION CONTINUES Deforestation has resulted in the reduction ofindigenous forests to four-fifths of their pre-agricultural area. Indigenous forests now cover 21%of the earths land surface.
  3. 3. WHAT ARE FORESTS AND WOODLANDS? In a forest the crowns of individual trees touchto form a single canopy. In a woodland, trees grow far apart, so that thecanopy is open.
  4. 4. HOW DOES DEFORESTATION HAPPEN Deforestation is brought about by the following: * Conversion of forests and woodlands toagricultural land to feed growing numbers ofpeople. * Development of cash crops and cattleranching, both of which earn money for tropicalcountries.
  5. 5. HOW DOES IT HAPPEN CONTINUES Commercial logging (which supplies the worldmarket with woods such as meranti, teak, mahoganyand ebony) destroys trees as well as opening upforests for agriculture; * Felling of trees for firewood and buildingmaterial; the heavy lopping of foliage for fodder;and heavy browsing of saplings by domesticanimals like goats.
  6. 6. WHY To compound the problem, the poor soils of thehumid tropics do not support agriculture for long. Thus people are often forced to move on andclear more forests in order to maintain production
  7. 7. CONSEQUENCES OF D E F O R E S TA T I O N* A LT E R A T I O N O F LO C A L A N D G LO BA L C L I M A T E S T H RO U G H D I S RU P T I O N OF: a) The carbon cycle. Forests act as a major carbon storebecause carbon dioxide (CO2) is taken up from theatmosphere and used to produce the carbohydrates, fats, andproteins that make up the tree. When forests are cleared, and the trees are either burnt orrot, this carbon is released as CO2. This leads to an increase inthe atmospheric CO2 concentration. CO2 is the major contributor to the greenhouse effect. Itis estimated that deforestation contributes one-third of allCO2 releases caused by people.
  8. 8. CONSEQUENCES OF DEFORESTATION CONTINUES b) The water cycle. Trees draw ground water upthrough their roots and release it into the atmosphere(transpiration). In Amazonia over half of all the water circulatingthrough the regions ecosystem remains within theplants. With removal of part of the forest, the regioncannot hold as much water. The effect of this could bea drier climate.
  9. 9. CONSEQUENCES OF DEFORESTATION CONTINUES * Soil erosion With the loss of a protective cover of vegetation more soil islost. * Silting of water courses, lakes and dams This occurs as a result of soilerosion. * Extinction of species which depend on the forest for survival. Forestscontain more than half of all species on our planet - as the habitat of these species isdestroyed, so the number of species declines (see Enviro Facts "Biodiversity"). * Desertification The causes of desertification are complex, but deforestationis one of the contributing factors (see Enviro Facts "Desertification")
  10. 10. LIST OF REFERENCES THE GAIA ATLAS OF PLANET MANAGEMENT. N Myers(ed.). Pan Books, London, 1985. BEHIND THE WOODFUEL CRISIS. G. Leach and L.Mearns. Capetown: Oxford University. South Africa, 1988. THE FUELWOOD TRAP: A STUDY OF THE SADCCREGION. B. Munslow. United States of America: McGraw Hill. 2003. WHOSE TREES? A PEOPLES VIEW OF FORESTRY AID.M. Hisham and J. Sharma. Panos Institute, London, 1991. WWF ATLAS OF THE ENVIRONMENT. G. Lean and D.Hinrichsen. Helcoan Publishing, Oxford,U.K., 1992.

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