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Chapter12
Maintainingbiodiversity,benefitsofecosystemsandglobalfoodproduction
ConservationConservationistheprotectionofplants,animalsandnaturalareasfromthedamagingeffectsofhumanactivity.
Conservationhasthefollowingbenefits:o prevents extinction - thecorncrakeandsomeorchidsinIreland
o maintains awiderangeoflivingthings(biodiversity)o maintainsthebalanceofnatureo allowsfuturegenerationstoseethewiderangeoflivingthingsthatarepresentnow
o wemayfindusefulproductsinplantsinthefuture(sowedon'twanttowipethemoutnow).
HomeworkBookpg120Q12.6&12.7
ConservationConservationmaybesupportedby:
o peoplebeingawareoftheissueswithregardtonature
o joiningconservationgroupso supportingconservationgroups
o notcarryingoutactionsthatwouldharmournaturalsurroundings
o onlybuyingproductsthathavebeenproducedwithconservationinmind.
HomeworkBookp121Q12.8,12.9,12.10
ThemaincausesofextinctionThemaincausesoftheextinctionoflivingthingsare:
o thelossofsuitablehabitats(orhabitatsbeingbrokenup)o pollutiono invasivespecies(organismsthatareintroducedtoanareaandcauseharm– nativeredsquirrelaffectedbyinvasivegreysquirrel)
o climatechangeo theoveruseofwildlifeo increasinghumannumbers.
HabitatlossorfragmentationHabitatlossexamplesinclude:
o cuttingdownforestsandwoodlandsfortimberorforbuilding
o drainingbogsforfarmingo usinggrasslandsforbuilding(roads,houses,factories,etc.)o pollutinglakessonothingcanliveinthem.Damagingahabitatkillsthelivingthingsinthathabitat.
Ifalargehabitatisbrokenup(orfragmented)thenlivingthingsmaynotbeabletosurviveinthesmallersectionsofthehabitatbeabletotravelfromonearetoanotherofthefragmentedhabitat.
PollutionPollutionistheadditionofunwantedmaterialintotheenvironment.
Theunwantedmaterialsarecalledpollutants.
Pollutionmayaffect:o theairo watero soil.
PollutionAirispollutedby:
o greenhousegases(suchascarbondioxideormethane)o acidrain(seechapter41)o CFCs(chlorofluorocarbonsinaerosols)o dirtparticleso smog.
Waterispollutedby:o badlytreatedsewage (toilet)wasteo oilspillso dumping ofhousehold,farmingandindustrialwaste.
Soilispollutedby:o acidraino overuseoffertilisersandslurry (liquidanimalwaste)o improperdumping ofwaste.
HomeworkBookpg 123Q12.14,12.17
Conservingbiodiversity
Biodiversitycanbeconservedby:o preventingthelossofsuitablehabitatso controllingpollutiono notintroducinginvasivespecieso controllingclimatechangeo notexploitingwildlifeo controllingtheriseinhumannumbers.
WastemanagementPollutioncanbecontrolledbyproperwastemanagement.
Wastemanagementinvolvesthe3Rs:
o Reduce theuseofunnecessarypackaging
o Reuse asmanymaterialsaspossible(e.g.Glass,secondhandfurniture,plasticshoppingbags)
o Recycle asmuchwasteaspossible(e.g.Paper,glass,metalsandsomeplastics).
Homeworkpg 125Q12.19,12.20,12.21
Activity12.1:Topurifywater1. Collectsomemuddyordirtywater.2. Pourhalfofthemuddywaterintoabeaker(touseasacontrolor
comparisonwiththetreatedwater).3. Pourtherestofthemuddywaterintoalargeplasticbottle,sealitandshake
strongly.4. Transferthemuddywaterfromthebottletoalargeemptybeakerandback
againtothebottleseveraltimes(thiswillaerateoraddairtothewater).5. Cutthetopoffanotherlargeplasticbottleandtransferthemuddy,aerated
watertothisbottle.6. Addsomealumsolutiontothewaterandstirslowlyforafewminutes(the
waterisseentoclearslowly).7. Letthewatersitundisturbedforabout20minutes(thewaterclearsslightly
asthetinyparticlesinthewatersettletothebottom).
Activity12.1:Topurifywater
Activity12.1:Topurifywater1. Usethetoppartofthecutupplasticbottleand
o placeafilterpaperoverthemouthofthebottleo secureitwithanelectric(rubber)bando placeitupsidedowninabeaker.
2. Gentlypourequalamountsofo pebbleso coarsesando finesandintotheneckofthebottle.
3. Pouralotofcleantapwatergentlyontothesandinthebottle(thiswillcleanthesandandpebbles,throwawaythewaterthatpassesthrough).
4. Pourmostofthedirtywatergentlyontothesand,butdonotallowanyofthesedimenttopourout).
5. Comparethewaterthatpassesthroughthesandandpebbles(thefiltrate)to:o thewaterremainingontopofthesediment(slightlydirtylooking)o theoriginalmuddywatersample(verydirty).
6. Rememberthatthefilteredwaterlookscleanerbutitisnotsafetodrink(itmaycontaininvisiblemicroorganismsthatcauseinfection).
Activity12.1:Topurifywater
HomeworkBookpg 129Q12.23,12.24,12.25,12.26
EcosystemAnecosystemisalargeareacontainingsimilartypesofenvironmentsandlivingthings.
Thebenefitsofecosystemsinclude:o supportingbenefitso productsbenefitso controllingbenefitso culturalbenefits.
SupportingbenefitsofecosystemsSupportingbenefits(theseallowtheotherthreetypesofbenefitstoexist)include:
o theyallowbiodiversityo theyhelpsoilformationo theysupport
photosynthesis(whichreducescarbondioxideconcentrations)
o theyallownutrientstorecyclewhenorganismsdieandrot(seechapter39)
o theyencouragewatertorecyclefromthesoil,intoplantsandbackintotheair).
ProductsbenefitsofecosystemsProductsbenefitsmeansthatecosystemsproduce:
o woodo fuel (turf/peatandfirewood)
o foodo freshwatero medicineso usefulchemicals.
ControllingbenefitsofecosystemsControllingbenefitsmeansthatecosystemshelptocontrol:
o airquality(plantsabsorbcarbondioxideandreleaseoxygen)o waterquality(waterispurifiedasitpassesthroughthesoil)o pollinationo soilerosion(rootssupportthesoil)o flooddamage(waterisabsorbedordiverted)o pestcontrol(pestsareeatenorweakenedbyparasites).
CulturalbenefitsofecosystemsCulturalbenefitsmeansthatecosystemsareusedfor:
o recreation (parks,mountains,seasides)
o sports (swimming,walking,climbing)
o appreciatingnature(takingpictures,paintingwildlife,naturefilms)
o education (fieldtrips)o science (outdoorresearch)
HomeworkBookpg 127Q12.22
TheGreenRevolutionAshumanpopulationnumbersincreaseitisnecessarytoproducemorefood.From1950tothelate1960smorefoodwasproducedduetothe‘GreenRevolution’.
Thehugeincreaseinfoodproductionduetothe‘GreenRevolution’hadsomenegativeeffects:
o newsupercropsmeantthatmanyoldercropswerenolongersown.
o thenewcropsneededlargeamountsoffertiliserandpesticides(tokillinsects).
o thenewcropsneededmorewaterandmoreintensefarmequipment(tractors,sprayers,etc.).
o landthathadarichbiodiversitywasconvertedtogrowingsinglecrops(calledmonoculture).
TheGreenRevolution
IncreasingworldwidefoodproductionThetwomainwaysofincreasingworldwidefoodproductionareto:
o convertmorelandtogrowingcropso increasetheyieldoffoodfromfarmlandinpresentuse.
Increasingtheamountoffarmland:o Atpresent
Ø 66%oftheEarth'ssurfaceiswaterØ 10%oftheEarth'ssurfaceisfarmland.
o HowevermuchoftheremaininglandcannotbeusedforcropsasitisØ toodryØ toowetØ toohotØ toodryØ poorsoil.
Usingmorelandforcropswilldestroybiodiversity.
NormanBorlaugvideoedcolearning.ie
IncreasingcropyieldsIncreasingcropyieldsisthebestmethodofincreasingglobalfoodproduction.Newcropsarebeingresearchedusing:
o seedsofoldercropswhichhavebeenpreservedo cropswithnewgenesaddedtomakethemmoreproductive.
Itishopedthatthenewcropswillresult in:o haveincreasedfoodyieldso producemorethanonecropperyearo resisthigherglobaltemperatureso uselessfreshwatero resistpestsanddiseaseso containmorenutrientso havebettertastes.
HomeworkBookp131Q12.28,12.29
TheFoodGapThefoodgapisthedifferencebetweentheamountoffoodproducedandtheamountneeded.Wecanreducethefoodgap(foodshortage)byreducingthelossorwasteoffoodfromitspresenthighof33%by:o changingourdietbyeatingmoreplant
materialandlessmeat(especiallybeef)
o increasingthegrowthofcropsonpoorqualityland
o improvingouruseofexistinglandandwateruse
o controllinghumanpopulationincreaseo growingmorewaterbasedfoods
(aquaculture).
HomeworkBookp132Q12.31,12.32
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