CHAPTER 9:ENDANGERED ECOSYSTEM

9.1 : HUMAN ACTIVITIES THAT ENDANGER AN ECOSYSTEM

Nurul NazihahNur Afiqah

Nor Syafiqah

Human activities which threaten the ecosystem: ~development and industrialisation. ~increase in the number of motor vehicles. ~increase the usage of pesticides and chemical fertilisers in the agriculture sector. ~uncontrolled deforestation.

The impact of human activities on the ecosystem: ~soil erosion. ~flash flood. ~landslide. ~eutrophication. ~water,air,thermal and noise pollution. ~global warming. ~depletion or thinning of the ozone layer. ~climatic change. ~extinction of living things.

POLLUTION (undesirable change in the physical chemical or unbiological characteristic of the natural environment,brought about by human activities)

AirPollution

Water Pollution

Thermal Pollution

Noise Pollution

Air PollutionCaused by the presence of pollutants in the air which are

harmful to life and the environment.Sources of pollution: a)Burning rubbish,forest,solid waste. b)Factories and industries burning of fossil fuel. c)Motor vehicles release harmful gaseous.(CO)Effects:~Cause respiratory diseases such as lung cancer.~Dust that cover the plant will block the stomata.~Soot and dust will blackens the buildings.~Form haze which is harmful to humans.~Reduces agricultural productivity.(e.g:photosynthesis)

Water PollutionCaused by domestic wastes,industrial wastes, soil

erosoin and agricultured waste that are discharged directly into rivers.

Souces of pollution:

a)Discharge of untreated sewage and domestic waste into rivers.

b)Discharge of industrial waste.

c)Discharge of agricultural waste.

d)Oil spillage.Effects:

~Causes death to all life forms in the sea.

~Pollutes the beaches.

EutrophicationOccurs when inorganic nutrients and organic material

enter a river or a lake.Effects:

a)Encourages photosynthesising organisms in the

water ,particularly algae to grow rapidly.

b)Light intensity in the water is greatly reduced.

c)Causing the death of aerobic organisms when

depletion of oxygen in the water occurs.

d)The use up of oxygen supply by the bacteria will

increase the biochemical oxygen deman(B.O.D.)

Biochemical Oxygen Deman(B.O.D.)

The amount of oxygen taken up by the micoorganism that decompose organic waste matter in water.

The uses of B.O.D.:

a)As a measure of certain types of organic pollutants

in water.

b)Measure the level of water pollution.

c)Indicates the presence of a microorganisms which

suggest a level of pollution.

Thermal PollutionThe release of excessive heat into the environment.Sources of pollution:

a)Discharged of hot water from factories,nuclear

reactors and electric power stations.

b)Glass buildings.Effects:

a)Cause instant death to some species.

b)Distrupt the entire ecosystem.

c)Encourages rapid growth for algae.

Noise PollutionThe occurrence of excessive noise in the environment

that disturbs the tranquality of life.Sources of pollution:

a)Trains and cars.

b)Construction sites.

c)Machines and equipment in factories.Effects:

a)Hearing problems.(deafness)

b)High blood pressure.

c)Emotional and mental disturbances.

The END…