Deforestation and Its Effects1

8/8/2019 Deforestation and Its Effects1

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DD eforestatioeforestatio

nn AAndnd IItsts EE ffectsffectsGroup Members:Kimberly Moh

Yeow Joo AnnBithiahZhu Yi Dan

Class:4 Beta Teacher: Miss Voo.Subject:Biology


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Definition Of Definition Of DeforestationDeforestation Deforestation is the clearance of

naturally occurring forests by the

processes of logging and/or burningof trees in a forested area.


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In troductionIn troduction Deforestation is the permanent

destruction of indigenous forestsand woodlands. The term does not

include the removal of industrialforests such as plantations. It hasresulted in the reduction of indigenous forests to 4 /5 of their

pre-agricultural area.
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Deforestation is a problem that iscaused largely by greed and want forproperty, money and possibly status. Inmany parts of the world the forest is

taken for granted as a replenishableresource, which it is. The problem isthat the trees


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c annot be regrown and replanted at therate at which they are being cut down.For this reason the forests are decliningat an incredible rate and there is noforseeable future for places like theAmazon which remained untouched for

20 000 years and now could bedestroyed in less than a human's lifetime.


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Deforestation is a problem with farreaching consequences rangingfrom a barren landscape to ahigher Carbon Dioxide levels in

the air. The underlying point isthat we have to pull together tostop the destruction of the

world's woodlands and forests.


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Important ElogicalImportant ElogicalRoles of TropicalRoles of Tropical

RainforesetsRainforesetsRainforests are theoldest ecosystemson Earth and housealmost half of theflora and fauna of

the world.

They contain many uniquespecies which provide food,medicine and other biological

products.Plants fromthetropical rainforests provide

about one quarter of

pharmaceutical productsavailable today.


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According to the NationalCancer Institute, 70% of the

plants useful in treatment of cancer can only be found inthe tropical rainforests.


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Rainforests regulate climate byinfluencing wind, rainfall, humidity

and temperature patterns. Rainforests are also called the carbon

sink of the Earth because theyabsorb vast amounts of carbondioxide during photosynthesis and atthe same time release oxygen intothe atmosphere


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They also server as watercatchment areas.

Despite their importance, it hasbeen estimated that more than50 million acres of rainforests aredestroyed or seriously degradedevery year. In general,

deforestation results in


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Soil erosion Flash floods Landslides

Disruption to the carbonand nitrogen cycles Severe climatic changes The loss of biodiversity


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1. Without proper developmentand planning, a land strippedof its vegetation is subject tosoil erosion. Soil erosion is theremoval and thinning of thesoil layer due to physical and

Deforestation causes soilDeforestation causes soil

erosion, landslides anderosion, landslides andflashfloodflashflood


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climatic processes, such as highrainfalls.

2. The absence of plant root systemmakes the soil structure unstable.

3. When there are heavy rains for along periods of time, the top layer

of soil crumbles and this leads tolandslides on the steep hill slides.


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4. The eroded soil is thencarried by moving water anddeposited at the bottom ofrivers.

5. This, together with depletionof water catchment areas,causes flash floods during therainy seasons.


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What areWhat arethese ???????these ???????


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Soil ErosionSoil Erosion


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LandslidLandslid

eses(Living(Living

on theon theEDGE)EDGE)


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FlashFlashfloodsfloods


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DeforestatioDeforestation results inn results inthe loss of the loss of biodiversitybiodiversity


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Deforestation has a

devastating effect on thebiodiversity in tropicalrainforests . The destruction

of millions of hectares offorests by human activitiesmeans :

(a)the removal of the bases

of numerous food webs


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(b) the loss of habitatsloss of habitats ofmany species of flora fauna

(c) the extinction of countless species and varieties of plantsand animals. The extinction offlora and fauna species reduces

the biodiversity . Biodiversitycan be a rich source of foodand priceless medicines tomankind.


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Deforestationcauses climatic

changes-

Deforestation disrupts thenormal weather patterns,

creating hotter, drier

weather and causing globalclimatic changes.

The removal of treesreduces transpiration,rainfall and the rate at

which plants absorb carbondioxide from the

atmosphere duringphotosynthesis.


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This lead to an increase in thecarbon dioxide level in theatmosphere. High level of

carbon dioxide prevent heatfrom escaping from theatmosphere. This is known asthe greenhouseeffect which isbelieved to lead to globalwarming.


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Forest clearingand burning of wood result in

air pollutionand release

more carbondioxide into the

atmosphere.

Burning of treesin the tropicsadds about25% more

carbon dioxideto the

atmosphere.


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.

DeforestatioDeforestatio

n disruptsn disruptsthe carbonthe carbonand nitrogenand nitrogen


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1.The removal of plant in the

rainforests disrupts

the natural cycle of nutrients .

2.The level of atmospheric carbondioxide rises as less

carbon dioxide in theair is removed by

plants duringphotosynthesis


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3.The level of atmospheric

oxygen drops asless oxygen isreleased by

plants duringphotosynthesis.

4.The

recycling of nitrates andother ions

slows down.

5.Tree roots bindsoil particles

together ,andthe tree canopy

cushions theforce of rain

beating down onthe soil .

Deforestation,therefore ,causes

the loss of nutrients throughleaching and run

offs.


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DeforestatDeforestationion

di tdi t


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1.The removal of plant inthe rainforests disrupts thenatural cycle of nutrients .

2.The level of atmosphericcarbon dioxide rises as lesscarbon dioxide in the air isremoved by plants during

photosynthesis .

3.The level of atmosphericoxygen drops as lessoxygen is released by

plants during

photosynthesis.


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4.The recycling of nitrates and otherions slows down.

5.Tree roots bind soilparticles together

,and the tree canopy

cushions the force of rain beating down onthe soil .

Deforestation,therefore ,causes the

loss of nutrientsthrough leaching and


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Solving to theSolving to theProblemProblem To prevent deforestationis a personal

undertaking, where youdo your best to conservethe wood you use. You

can also get involved atyour school and try toget some money

together and use it to


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write to your municipality to askthem to hold back on the cutting

down of trees. You must telleveryone that you know about theeffects of deforestation and explainhow they can help. If you needguidance as to how to go aboutpreserving nature, ask an adult orteacher. Always try to limit thewood etc, that you use. Do not by


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excessiveamounts of

wooden itemsas this only

encourages the

people whoowntimbermills and

logging

companies.


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THE ENDTHE END Thank you. Thank you. Resources:Resources:

Biology text book form 4Biology text book form 4(pg292-294)(pg292-294)

http://library.thinkquest.org/Chttp://library.thinkquest.org/C0127068/deforestation.html0127068/deforestation.html

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Deforestation and Its Effects1