FORESTS
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FORESTS
Kinds of forest. Geographical distribution. Importance of forests.Forests maintain the highest bio-diversity on our planet. Problem ofdeforestation.
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INTRODUCTION
Around 4,600 years ago some tiny pine seeds germinated on a rocky mountain slope in California. These seeds converted themselves into trees.
Their thousands of rings have recorded changes in out past climate, earthquakes and volcanic eruptions.
FORESTS
The Carboniferus Age: forests covered practically the entire surface of our planet and insects dominated dry-land.
Huge brush fires raged accross the face of the earth during hundred of years.
Photosynthesis and the Sun.
Microclimates.
The main factor governing the structure, growth and permanency of any wood of forest is light itself, which is absolutely necessary for plants’ growth.
Different adaptations to catch more light.
Different species of plants spread themeselves over different levels.
Task of the trees’ folliage.
Development of animal life.
DISTRIBUTION OF FORESTS
Localisation of forests.
The Taiga.
Temperate forests.
Tropical forests.
Jungles.
The human activity is causing tropical forests all over the planet to disappear.
DEFORESTATION
Only a few decades ago, almost two-thirds of the earth’s surface was covered by forests. Nowadays, this area has been reduced to less than one-third.
85% of African jungles, 75% of Asian jungles and 50% of American jungles have disappeared.
Causes of deforestation: farming, livestock, wood used as combustible, wood used in the furniture and paper manufacturing industries.
Its consequences: erosion of the soil, desertisation, increase of floodings.
SUMMARY |
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