Biologi Endagered Ecosystem

8/6/2019 Biologi Endagered Ecosystem

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INTRODUCTION

Great challenges in todays world have lead to various development projects. The projects

or human activities, if unplanned and mismanaged, can upset the balance of the natural

environment and damaged the ecosystem.

A new report shows that some 60 per cent of the benefits that the global ecosystem

provides to support life on Earth (such as fresh water, clean air, and a relatively stable climate)

are being degraded or used unsustainably. In the report, scientist working on the Millennium

Ecosystem Assessment (MA) warns that harmful consequences of this degradation to human

health are already being felt and could grow significantly worse over the next 50 years.

So, we as human being have an important responsibility to manage the environment. The

Earth can only be a better place if development activities are planned with a great care.


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Objective

Learning outcomes

y Identify human activities that threaten the ecosystem.y Explain the impact of human activities on the ecosystem.y Evaluate critically the effect of unplanned development and mismanagement of the

ecosystem.

y Describe types of pollution.y Explain the effect of pollution on living thing and the environmenty Compare and contras pollutants in the air from different environment.y

State the source of air pollution.y Interpret data on the level of air pollution in some cities.y Make an inference on the source of the air pollution in some cities.y Interpret data on the level of water pollution in some rivers.y Predict the level of air and water pollution in a particular location within the next ten

years.

y Suggest strategies to solve problem related to in air and water pollution.


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Impact of human activities

Human activities which threaten the ecosystem are:

y Developmenty Increase in the number of motor vehiclesy Increase in the usage of pesticides and chemical fertilizers in the agriculture sectory Uncontrolled deforestation

The effects of unplanned development and mismanagement of the ecosystem are:

y Soil erosiony Flash floody Landslidey Eutrophicationy Water, air, thermal, and noise pollutiony Global warming (phenomenon of increase in temperature of the Earth, also known as

the greenhouse effect)

y Depletion of the ozone layery Climatic changey Extinction of living things


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Pollution

Air pollution

- Caused by the presence of pollutants in the air which are harmful to life and theenvironment.

Source of pollution are:

.

Effects of air pollution

y Acidic gaseous pollutant cause respiratory diseases such as bronchitis, breathlessness,lung cancer and asthma

y These pollutants irritate eye, cause skin diseases and conjunctivitisy Increases the acidity in the soil and cause the soil to be infertile.y Acid rain reduces the pH level of the lakes and the rivers and threatens the aquatic lifey Acid rain corrodes metal structure and erodes limestone used for making building

sourceof

pollution

factories

motor vehicles

Sulphur dioxideand nitrogen

that dissolve inwater vapourwhich lead to

acid rain

increase in co2

burning


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Water pollution

- Caused by domestic wastes, industrial wastes, and agriculture wastes that aredischarged directly into the rivers

Source of water pollution Harmful effectDischarge of untreated sewage and domestic

waste into rivers

y Encourage growth of bacteria, causingdiseases such as cholera

y Number of bacteria increases due toincreased concentration of nitrates and

phosphates in untreated sewage

y Cause bad odour and unsightly viewDischarge of industrial wastes y Contaminate the water physically

y Decomposition of organic wastes reducesthe concentration of oxygen in the water

Discharge of agriculture wastesy Cause Eutrophicationy Agrochemicals are poisonous to aquatic

animals and cause cancer

Oil spillage y Cause death to all life forms in the seay Pollute the beaches


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Eutrophication

Eutrophication occurs when large quantities of nutrients such as nitrates and

phosphates enter an aquatic environment. Sources of these nutrients include animal wastes,

agricultural runoff, and sewage. The ecosystem quickly experiences and increase in

photosynthetic and blue-green algae, as these organisms thrive in the presence of the added

nutrients. An algae bloom occurs as the algae accumulates into dense, visible patches near the

surface of the water, prohibiting light from penetrating deeper areas of the lake or stream.

Some fish are unable to survive without this light, but for them an even more serious problem

arises when the algae begin to die. At this point, oxygen-demanding bacteria take over the

ecosystem, decomposing the algae and using up dissolved oxygen in the process. These

bacteria increase the biological oxygen demand (BOD) of the ecosystem. BOD is the amount of

oxygen required for the decomposition of organic compounds by microorganisms in a given

amount of water. It is usually measured in milligrams of oxygen consumed per litre of water.

Biological oxygen demand is important because it affects the amount of dissolved oxygen

available to all species in an aquatic ecosystem. A higher BOD indicates a lower level of

dissolved oxygen. This lower concentration of oxygen causes many fish suffocate, and as the die,

the number of oxygen-demanding decomposers increases even more.


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Thermal pollution

- The release of excessive heat into the environment.

Effects of thermal pollution:

Increase the temperaturein the rivers will increase

the process ofdecomposition and

increase the BOD valueReduces the solubility of

oxygen in the water

thesources of

thermalpollution

discharge of hot

water from factories,nuclear reactors and

electric powerstations

glassbuilding


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Noise pollution

- The occurrence of excessive noise in the environment that disturbs the tranquillity oflife such as :

y The loudness of sound is measured using the decibel (dB) unity Human ears can only receive sound less than 80 dB

The sources of noise pollution are

Effects of noise pollution include:

y Hearing problems (deafness)y Ear injuryy Headachesy Emotional and mental disturbancesy High blood pressure

The sourcesof noise

pollution

Traffic

Machine andequipments

factories

AircraftsTrains

Constructionsites


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Greenhouse effect

The greenhouse effect is the heating of the surface of a planet or moon due to the

presence of an atmosphere containing gases that absorb and emit infrared radiation.

Greenhouse gases, which include water vapour, carbon dioxide, methane, CFC and nitrogen

dioxide, are almost transparent to solar radiation but strongly absorb and emit infrared

radiation. Thus, greenhouse gases trap heat within the surface-troposphere system. This

mechanism is fundamentally different from that of an actual greenhouse, which works by

isolating warm air inside the structure so that heat is not lost by convection. The greenhouse

effect was discovered by Joseph Fourier in 1824, first reliably experimented on by John Tyndall

in 1858, and first reported quantitatively by Svante Arrhenius in 1896. Greenhouse effect

makes the earths temperature rises causing global warming.


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The following human activities can increase the concentration of carbon dioxide in the

atmosphere to cause a greenhouse effect are:

y Burning of fuels in factoriesy Forest firesy Deforestationy Open burning of rubbishy Coal-fuelled power-stationsy Use ofCFC

The consequences of the greenhouse effect are:

i) caused by themelting of polar ice

caps

ii) low-laying areasaround the sea furtherlowered resulting infloods

i) the high atmospherictemperature speeds up

the rate of evaporationcausing drought andsudden floods.

ii) also changes in winddirection and seacurrent cause naturaldisaster such astyphoons andhurrincanes to occurmore frequently.

i) productivity of cropsand livestock is

reduced due todrought and extremelyhigh temperature


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Thinning of the ozone layer

Ozone is the made up of 3 oxygen atoms. It is located at stratosphere which is 20-50 km

above the earths surface. The ozone layer absorbs the harmful ultraviolet rays and prevents

them from reaching the earths surface. It was found that the depletion of the ozone layer

occurred over both the Arctic an Antarctic, creating the ozone holes. The ozone hole in the

Antarctic is found to be is big as the USA. The depletion of the ozone is caused by the increasing

use ofCFC which can break down and convert ozone molecules into other molecules. Other

pollutants such as halons, chlorine gas, and nitrogen oxides can also destroy the ozone.

Effects of the thinning of the ozone layer which allow excessive ultraviolet radiation to

reach the Earth:

On the environment y Increases the temperature of the environmenty Changes in the climate and weather patternsy Changes in wind direction

On plants y The rate of photosynthesis decrease due to destruction ofstomata and chlorophyll in the leaves

y Disturbs the ecological balance by destroying aquatic organismssuch as planktons.

On human health y Causes skin cancer (melanoma)y Damage eyesight and causes cataracty Weakens the human immune system


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Impact of the Thinning of the Ozone Layer and Global Warming on the Ecosystem

1. The thinning of the ozone layer allows ultraviolet radiation to reach the Earth surfaceand destroy the planktons in the food chains. This problem threatens other marine life.

2. Reduce the number of stomata and amount of chlorophyll in the leaves. The plantcannot carry out photosynthesis. The plant will die and the biotic component in the

ecosystem threatens.

3. Global warming causes the atmosphere to be very hot, resulting in drought and changesin the climate. This affects the biotic component in the ecosystem which consequently

affects the distribution and population of the biotic component.


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Steps to maintain a stable environment

y Implementation of lawsi. The Environmental Quality Act 1874, 1985 (amendment) :

- Control and prevent pollution of the environment (covering air, water, thermaland noise pollution)

- Coordinate all activities related to waste disposal and fix the maximum light ofwaste to be disposed

- Control the extent of waste production (amount, type, content, and effect) so asnot to threaten the quality of that environment

ii. Factory and Machine Act 1967/1983 to protect the workers from being exposed tonoise levels of more than 95 dB for 4 hours continuously.

iii. Pesticides Act 1974 to control the usage of pesticides.iv. National Forestry Act 1984 to protect and preserve forest as well as all wild-life in the

forests

y Use of technologyi. Install factory chimney that have specific devices to filter fine particles and toxic gases

before they are released into the air

ii. Use of oil-disintegration bacteria to clean up oil spillage the seaiii. Recycle wastes made of manufactured materials such as glass, metal, paper and

aluminium cans to protect the environment and conserve natural resources


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4R

reuse means usethings such as old

plastics containers andbottles again instead

of throwing themaway

reduce means cuttingdown on the use ofmaterials which arenon-biodegradable

renew means to usematerials such as

bottles and plasticcontainers after they

are released

recycle meanscollecting segregatingwaste according to thetypes of materials andturning this waste into

new products

y Education on the management of resourcesi. The public must be educated on the concept of 4R


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y Preservation and conservation of the ecosystemi. Preservation involves efforts to protect an ecosystemii. Conservation involves efforts to return an affected ecosystem to its natural

equilibrium and keep them good.

iii. P

reservation is better than conservationiv. The efforts of conservation includes

- Preservations of soil- Preservations of water- Preservations of flora and fauna- Preservations of mangrove swamps

y The practice of biological controli. Biological control is the use of natural predators to control the population of pest

species such as:

-

The use ofkhaki chambel(a species of ducks) to control the population of goldsnails (siput gondang emas) which feeds on paddy stalks

- The use of owls to control the populations of rats in oil palm plantations- The use of hoverfly larvae to control aphids which feed on crop plants

y The use of renewable energyi. Renewable energy is energy flow that occurs naturally in the environment and can be

harnessed for the benefit of the humans

ii. Renewable energy is inexhaustible and does not pollute the airiii. Examples of renewable energy

- Solar energy (generates electricity)- Wind energy (to operate windmills)- Flowing water (generate hydroelectric power)- Wave energy (generates electricity)- Geothermal energy (generates electricity)- Biomass energy (produces biogas as fuel)- Gasohol (converted to ethanol as fuel)- Palm oil (converted to methyl ester as fuel)

y The efficient use of energyi. Reduce the burning of coal, petroleum and other fossil fuelsii. Substitute natural gas for coal at power plants

iii. Improve fuel efficiency in vehicle-use cars that run on energy-efficient enginesiv. Use a cleaner fuel by reducing the content of sulphur in diesel and switching to gasv. Improve energy efficiency in factoriesvi. Use more hybrid car which combines electric and gasoline engines


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Conclusion

Management of the ecosystem is the task of maintaining the balance of nature by

means of preservations and conservation of natural resources as well as protecting the

ecosystem. Improper management of development activities can threaten the ecosystem.

Some activities can upset the balance in ecosystem such as disposal of rubbish freely in

all places which includes drains and rivers; open burning of rubbish and disposal of effluent

water from factories.

To ensure these activities do not destroy the ecosystem, the following measure can be

taken. Some examples are stricter law and closer supervision of responsible particles; educating

the public to cultivate an awareness to keep the environment clean and to care for the

ecosystem and carrying out programmes to recycle discarded wastes such as paper, glass and

aluminium cans.

Biologi Endagered Ecosystem

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