CHAPTER 9 :
ENDANGERED ECOSYSTEM
Prepared by : Cheow Hee Thong 4SB Cheong Qi Hui 4SB
Human Activities That Endangered or Threatened an Ecosystem
Human Activities That Have Undesirable Effects On The
Environment
Human Activities That Have Undesirable Effects On The
Environment
Human Activities That Have Undesirable Effects On The
Environment
Human Activities That Have Undesirable Effects On The
Environment
Deforestation and its Effects
The rapid destruction of woodlands.
OR
The removal of trees from forests.
DEFORESTATION causes :
(a) Soil Erosion, landslides and flash floods-> Without proper development and planning -> Absence of plant root systems -> Soil structure unstable (make the land infertile)-> When heavy rain, soil crumbles-> Leads to landslides-> When rainy season (long period), flash floods
happen
DEFORESTATION causes :
(b) Loss of Biodiversity-> Likely effects in tropical rainforests-> The removal of the bases of numerous food webs.-> Lost of habitats (Flora & Fauna)-> Extinction of varieties plants & animals
DEFORESTATION causes :
(c) Disruption of Carbon and Nitrogen cycles-> The level of atmospheric carbon dioxide RISES, as LESS
carbon dioxide in the air is removed by plants during photosynthesis.
-> The level of atmospheric oxygen DROPS, as LESS oxygen is released by plants during photosynthesis.
-> Loss of nutrients through leaching and run-offs.
Burning of Fossil Fuels and its Effects
-> Adds about 75% of carbon dioxide (CO₂) to the atmosphere.-> Increase of CO₂ causes greenhouse effect and global warming
EARTH IS VERY HOT!!!!!!!! SO…..
STOP BURNING!!!!
The Process of EUTROPHICATION
Carbon monoxide
Carbon dioxide
Fine particulate
matter, smoke and haze
Lead
Sulphur dioxide
Nitrogen oxide
• Colourless and odourless gas.• Sources : -combustion fossil fuel -exhausts of vehicles• Effects : -Combines with haemoglobin and
affects the transport of oxygen to body cells. -Causes fatigue and headaches.
• SO2 formed when sulphuric compounds react with oxygen when combustion.
• Sources : -Burning of fossil fuels. -Volcanic gases.
• Effects : -Irritates eyes. -Cause asthmatic attacks.
• Solution : -Use low sulphur content fuels.
• Sources : -Vehicle exhausts -Factories
• Effects : - Irritates lungs, nose, throat and eyes. -Cause respiratory infections.
• Solution : -Clean up emissions from car exhausts by installing catalytic converters to turn oxides of nitrogen into harmless nitrogen gas.
• A complex mixture of fine liquid droplets/solid particles in the air, such as dust, smoke.
• Sources : -Incomplete combustion fossil fuels. Ex: The burning of oil wells and
dried paddy stalks. -Motorised vehicles.
• Effects : -Irritates the eyes, nose and lungs -Dust cause lung diseases. -Smoke & haze can reduce light
intensity.• Solution : -More efficient burning of fuels in well
designed furnaces. -Stop open burning.
Lung Diseases
Designed Furnaces
• Pb added to petrol to prevent inefficient burning of petrol-air mixture.
• Sources : -Poisonous lead compounds released into atmosphere when fuels burnt.
-Vehicle exhaust fumes.• Effects : -Damage the liver.
-Can result in coma or death.
• Solution : -Use unleaded petrol.
• Acidic, colourless & odourless gas.
• Sources : -Open burning. -Combustion fossil fuel.
• Effects : -Greenhouse effect & global warming. -Atmospheric temperature increase.
• Solution : -Reduce the use of fossil fuels.
Atmospheric temperature
increases
• Acid rain is rain that is more acidic than normal.
• Acid rain damage involves weather, chemistry, soil, and the life cycles of plants and animals on the land and from acid rain in the water.
• Sulphur dioxide and nitrogen oxides are the major sources of acid rain.
• The combustion of fossil fuels(coal, air and gas) in factories, power station & domestic boilers releases sulphur dioxide(SO2) and oxides of nitrogen(NO and NO2).
• SO2 and oxides of nitrogen combine with water vapour in atmosphere to form sulphuric acid & nitric acid.
• Then they fall to Earth as acid rain.• Rain is acidic, with a pH of about 5.6.
Power Dtation
Domestic Boilers
Effects of acid rainEffects of acid rain• Soil becomes acidic and unsuitable for the
cultivation of crops.• Cause the leaching of minerals (potassiun,
calcium & magnesium).This affects the growth of crops.
• Increased acidity in the aquatic ecosystems also kills phytoplankton which changes the food chain.
• Acid rain can be reduced by: Cleaning up emissions from power station
and industrial plants with scrubbers. To involves the spraying of water to trap pollutants.
Cleaning up emisions from vehicle exhausts with the use of catalytic converters. To produce less harmful products.
Scrubber
Catalytic Converters
• The air pollution index (API) is to measured the air quality.
• This index is calculated based on the concentrations of major air pollutants.
• Air pollution levels divided into 5 bands :
THANKS :DDD