12. maintaining biodiversitypresthurlesscience.weebly.com/.../12._maintaining_biodiversity.pdf ·...

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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