biology chapter 9 - endangered ecosystem

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