Chapter 19: Effects of human activity on the ecosystem
Deforestation
Is the cutting of trees.
^^Reasons:^^
Urban development
Cultivation
Grazing
Timber
Fibres
^^Effects of deforestation:^^
Soil erosion
Flooding
Desertification:
Loss of habitats.
Extinction of species.
Loss of robust wild species of plant.
Imbalance b/w O2 and CO2 concentration in air.
Climatic changes.
Pollution
^^Pollutants^^:
Sulphur dioxide and nitrogen oxides - leads to acid rain and smog.
Lead - is poisonous if accumulated with consumed food.
Carbon monoxide - forms carboxyhemoglobin in blood.
Carbon dioxide - greenhouse effect.
Chlorofluorocarbons (CFC’s) - damage ozone layer.
^^Causes^^
Exhaust fumes from motor vehicles.
Chimney fumes.
Burning of garbage.
^^Ways of reducing^^
Use catalytic converters in cars.
Less use of cars.
Use filters or scrubbers on chimneys to remove sulphur dioxide.
Use of less fossil fuels in factories.
Use of alkalis to neutralize acidic waste products from factories before they are released to environment.
Use ozone - friendly products.
Water pollution
^^Causes^^:
Sewage
Inorganic waste
Fertilizers - eutrophication
Pesticides
Insecticides
Herbicides
Conservation
^^reasons^^
Ensure protection of plant and animals.
Maintenance of stable and balanced ecosystem.
Ensure conservation of marine life + tropical forests + natural scenery.
Scientific value.
^^Measures^^
Laws that prevent tree hunting and human activities that harm ecosystem.
Educate youth.
On fishing grounds - ban use of large nets + regulating size of ships + limiting period of fishing + banning harvesting endangered species + harvesting months.