B18 Biodiversity and Ecosytems Flashcards
What is biodiversity ?
The variety of all the different species of organisms on Earth .
-Biodiveristy can als refer to an individual ecosytem (biodversity in the amazon rainforest )
One reason biodiveristy is important for ecosytsems .
-Species depend on eachother for food and shelter .
Another reason biodveristy is important for ecosytems .
-Species also help to maintain the enivornemnt . For example , decomposers break down the remains df dead organsisms .
What does a high level of biodiversity mean ?
-There are a lot of different species , and this makes an eocystem more stable .
-As lots of different species means that the ecosytem is less dependant on one species .
-Therefore if the population of a species falls , it is less liekey to effect the whole ecosytem .
How are humans having a negative effect on biodiveristy ?
Example , deforestation .
-Tropicl forests contain a very rich biodiversity . However , large areas of these ofretss are being destroyed to provide land .
IN EXAM YOU CAN BE AKSED FOR THIS .
EXAM QUESTION ,,, Why are humans doing deforestation ?
-The land is used for rice fields or for grazing cattle .
-The land is used to grow crops which are then used to make biofuels .
-Over the last hundred years , the opulation of humans has increased massively as wella s the averge standard of living .
Because of this , humans are using more of the Earth’s resources than ever before .
-They are also producing more waste that is leading to pollutoin .
An example of water pollution
Humans porduce a large amouont of sweage , this contains urine and faeces .
-In the UK , sewage is treated before being released .
-However , in some cases , untreated sewafe is accidetally released into rivers or streams ..
How else can rivers and streams be polluted ?
By fertilsiers onf arms .
-both fertilisrs and untreated sewafe causes dissolved oxygen levells to fall and this can kill aquatic chemicals .
How else can rivers and streams be polluted .
-Toxic chemicals are released into rivers form factroies , and these can kill animals in the rivers .
WASTE FROM HUMAN ACTIVITY IS REDUCING BIODIVERISTY IN AQUATIC ECOSYTEMS .
Air pollution
-Waste from human activiies is also polluting the air .
-e.g burning coal in power stations can release acidic gases and these can cause acid rain .
-burnign lso releases smooke
AIR POLLUTION IKE THIS CAN KILL PLANTS AND ANIMALS AND THIS REDUCES BIODIVERSITY .
Land pollution
-Millions of tons of waste are dumped into landfills .
-Landfills destroy habitats for plants and animals .
Land pollution - Toixc Chemicals
-Toxic chemicals can also leach out of the landfills and pollute the soil .
-Toxic chemicals are simply dumped onto the land , all these are killing living organisms .
a note to take from pollutiion .
-From all these activities ,w aste from huamns is reducing biodveristy .
-Therefore , we need to carefully ahndle our waste material and dispose it without harming the environment .
temperautre like over the last hundred years
-avergae temeprature has been increasing
causes of temperature change ?
-Naatural changesi n the climate .
-However current increase is caused by human activity .
Human activity effecting cilmate ?
-For many decades now humans have release huge amounts of crbondioxide into the atmopshere . Mainly due to burning fossil fuels .
–Mehthane also release - which is porduced b y bacteria , i releasedin pddy rice field .
-cows passing wind .
Significance of Methane and arbondioxide
-Both cabrondioxide and methane are greenhouse gases so they trap heat in the atopshere leading to global warming .
What is peer review ?
-Thousands of scientifc papers have been published on global warming .
-These have been chekce dby other scientists before published this is PEER REVIEW .
-this hellps to detct flse claims , makes reasrch pblished in scientific journals valid .
example of something that is NOT peer re view
-Repororts in popular media , newspapers ar not subject to peer review .
-Some reports are just ismplifed , inaccurate or biased .
One consequence of temperatures on Earth increasing .
1.Loss of habitats
-Reduction in ice levels in the artic and this has cuased the populations of artic organisms like polar bears to decrease due to habitat reduction .
Another consequence of temperatures on Earth rising .
-Animals like birds and insects may gradually extend their range northward towards cooler conditions .
(MOSQUITO , can’t surive in the UK , but with global warming , they could spread to the UK and diseases like Malaria coul dbe brought with them .)
Final consequence o temperatures on Earth rising
-Migration patterns of animals may change .
-Effect palnts , like flowering seaons , some plant grown in palces htey could not before , ro some may not be able to be grown in a certain place again .
What is eutrophication ?
-The addition ofnutrients to water stryems that break down the natural chemical balance .
Stage one of eutrophication ?
-Farmers apply fertilisers containing nitrates and phosophates to their field .
Stage two of eutrophication ?
-Heavy rain washes the fertilisers off int rivers and lakes .
Stage three of eutrophication ?
-Nitrates abd phosphates encourga ealge to grown on the water’s surface .
Stage four of eutrophication ?
-Algae blocks sunlight reaching plnts below the surface .
Stage five of eutrophication ?
-Plants stop photosynthesising and releasing oxygen .
Stage six of eutrophication ?
-Decomposers break down dead plants and animals using up even more oxygen .
Stage seven of eutrophication ?
-Fish die due to lack of oxygen .
What is Bio -accumulation ?
-Toxic chemiclas such a spesticidies +herbcides or poisionous chemicals from landfill smight wash into water way .
-Th argest carnivores die or fail to breed beucse of th build of toxic chemicals in their bodies .
What is acid rain ?
-Sulphur impurities in fossil fuels react with oxygen when they are burnt forming sulfurdioxide.
-Nitrogen oxides are also produced . Thes gses dissolve in rianwter or snow to form sulfuric acid + nitric acid .
-what is smoke ?
-WHat is smog ?
-Smoke is tiny solid particlues produced through burning .
-Smog isi a combination of smoke and fog and other chemicals such as nitrogen oxide and sulfur dioxide.
Problems of smoke and og ?
-Gobal dimming as the particles reflect sunlight .
-respitory problems like Bronchitis , lack of oxygen being transported around the body becuse carbon monoixide BINDS to the haemoglobin in red blood cells .
What is food security ?
-Having enough food to feed a population .
it is IMPROTANT - as MORE poeple live in cities nd few people gro their OWN FOOD .
there are 6 biological threats to food security .
..
How is birth rate increasing a threat to food security ?
-As the population gorws , the amount of food availbe will have to increse to feed the whole population .
How is chaning diets an increasing threating to food security ?
-In developed countries like UK , our tastes are chaning .
-We now exoect to eat a whole range of different foods throughout the yar .
-Many of these foods annot be gwon in the Uk , so lots of importing of other countries has to be done HOEVER , THAT S A THREAT TO THEIR GOOF SECURITY .
How is food security threatened by pathogens and pests ?
PESTS EAT FOOD CROPS - catepillars .
-Pathogens cause infectious disease .
-Both of these reduce the moutn of food crops availabe to eat .
How are environmental changes a threat to food secuirty ?
-An effect of global warming is unpredictbale weather .
-If rainfall patters change , many countires may not be bal to grow enough crops to feed their population . Which could lead to famine .
How are modern farming methods a threat to food security ?
-Modern farming methods require a greta deal of new resources .
-E.g many farmers rely on fertilisers and pesticides to increse their crop yield .
-+Farmers producing livestock need ot buy food for hteir animals .
modern farming methods (2)
-As the populaiton of the world increases , these resources are becomign mroe expensive .
-In certian countries , increased cost may be more thnthey cn afford . Threatening the security of their food production .
How are conflicts a threat to food securiy ?
-During any period of war ,, farming can disruptted and improts of food may not be possible .
-Water can also threaten th reliable supply of water .
WHAT TO DO TO HELP WITH FOOD SECURITY ?!
-As the worlds popualtion increases , it is essential we use sustaibable methods to feed everyone on Erth .
THAT WAY our long term food security will be increased.
WAYS TO BE MORE SUSTAINABLE ?
-m-Maintainign osil quality so plans grow well year after year .
-Looking at more effient ways to produce food .
-Taking care of fishstock in the ocean os they don’t run out .
Why are humans reducing biodiversity ?
Becuase of our need for land . (Housing , facctories , shops +airports)
-Also use lands for farms and quarries ,as well as landfills .
-This means less land is aaiable for animals+plant , due to reduction in ahbitats reducing biodiversity .
What is an example of an area covering fromt his problem ?
PEAT
-Peat bogs and peat lands contain large amounts of dead plant materials .
-Conditions in peats means that decay is very slow . So peatbogs and peat glands contain a very large amount of trapped carbon , however these habitats are being destroyed .
Uses of peats ?
-Peats are used to produce cheap compost-for gardens and farms .
-Ins ome countires , peat is burned to release energy (for example to generate electricyt .)
-The destruction of peatbogs and pea lands reducing the area of this habitat is reducing the variety of plnts and microgranisms that lvie htere reducing bidoversity .
ANOTHER problem with peats ?
-Once hte peatws have been extracted , it is used for ocmpsots , it begins to devay , relesing laarge amounts of co2 into the tmoshpehre .
-A lot of peat is burned and relases co2 , contributing ot lcimsatechange .
-Many gardners have stopped buying compsots that contain peat , but an alternagtive like this is EXMPENSIVE , ffarmers using this can cause an icnreasein food price .
WHat is the first way of maintaining biodiviersity
1.Breeding porgrammes for endangeed species.
What is the second way of maintaining biodiversity ?
2.The destruction of habitats can reduce biodiversity so the protection and renhgeneration of rare habitats is important for preserving biodiversity .
What is the third way of maintaining biodiversity ?
3.Both fieldmargins and hedgerows help to preserve biodiversity on farms .
WHat is the fourth way of maintaining biodiveristy?
Governments - reducing co2 (uk renewbale nergy lke wind ) les co2 contirbuting to climate change and= therefore less loss of habitat ..
-Reducing deforrestation nantional prks in brazil to reduce deofrestation fo the amazon rainforest/
How could invidiauls maintain biodiversity ?
-Recyling waste amterial as lots of waste is simply dumped into landfills .
-This destryos habitats for plants and nimals .
-If we recyle less watse ends up in landfills , so fewer hbitats are destryoed having posiitve effects on biodiversity .
Scienttsts call positions on a food chain tropic levels
producers -L1
primary consumers-L2
Secondary Consumer -L3
Tertiary consumer -L4
WHAT ARE PREDATORS
Consumers that kills nd ets other nimals .
Predators rhat have no rpedators themeselevs are APEX predctors , at the top of the food chain.
What are decompsoers
Decompsoers break down dead plants+animlas , s waste porducts such as faeces .
-By breakgn down ded remians , decopoers return mineral ions back into the osil /.
How do decompsoers decompose ?
Decomposers secrete enzymes into the environment .
-The enzymes digest the dead materials and the small soluble food molecules then diffuse back into the decompsoers .
We can measure the MASS of al the organsisms at a certain trophic level , scientits call this hte biomass .
if a scientits wanted to workout the biomass of an animla in a good chain ;
1. Collect all the animals int hat area and kill them .
2.Then dry them and weigh them giving us dry biomass .
What is more useful dry or wet biomass ?
DRY bIOMASS IS MORE USEFUL THAN WET BIOMASS ,
- AS MOISTURE CONTENT OF ORGANSISMS , can vary widely , and porduce inaccurate reuslts .
(scientits dont wanan go aoreund killing animals so look up data in a scientific journal )
-If we plot the biomass at each trophic level , we can get a pryamid of biomass .
in EXAM , we could be asked to PLOT , a pyramid of biomass , from the data you are given .
L1 producers
-Only one percent of lgiht energ that falls on producers is absorbed and used for photosynthesis.
Key fact about biomass pyramids ? WHY DOES THIS HAPPEN ?
The amount of biomass decreses with each trophic level.
- Reason why the amount of biomass decreases with each trophic level.
-Not all the material an animla inests is absorbed. some is egested as faeces.
- Reason why the amount of biomass decreases with each trophic level.
2.Some of the biomass that is absorbed is converted into waste porducts of metabolism ,a dn then released example in huamsn is UREA .
- Reason why the amount of biomass decreases with each trophic level.
A large amount of the biomass used by animlas for respiration is to release neergy .
-Aerobic respiration also releases CO2 and H20 .
-SO osme of the biomass ins used to croduce wstecompunds .
-Energy fro respirtion is used in movement .
- Reason why the amount of biomass decreases with each trophic level.
In some mamamls , nergy is used to maintain a constant body temperture .
Due to all these oransism , the number of ORGANSISMS at each trophic level tends to decrease /
Do thre calcualte efficency of biomass transfer question .
efficency = gian in biomass/total biomass intake .
-The answer refelcts cows move around to maintain a constant tmeprature .
What are free range chickens ?
-They can move as mcuha s they want as they are porvided with food - but can also find their own food e.g isnectds.
Problem with free range chickens ?
A lot of the biomass the chicken eat , are being used in respiration providing energy for movement .
-ALso chickens when wether is old 0 energy is eeded to amintain body temperautre .
-Less biomass avaialable for chickens to grow and porduce eggs (same with sheep and goats ).
SOO , Uk farms moved to factory farming .
Chickens are raised in temperature controlled shed .
-The space int these sheds restricts the chicens movement so less biomass is wasted compared to free range eggs /
-Chickens are also fed high proteind iet .
-Becuase of this , cheksn produce more egegs and grow faster than free range eeggs .
Advanatges of factor farmimng (1)
-Factory farming is mroe efficent - so less biomass is wasted y animals in repsiration
Advanatgesof factory farming (2)
-Also can control the food that the aniamls eats , so can cotnrol all the nutirents they need , so less food is wastd .
Advanatages of facotry frming (3)
Eggs can more easily be harvested if the chickens are kept indoors .
Disadvanatges of factory farming (1)
When naimlas are lef in crowded conditions , infectios disease can spread more easily .
-TO prevent this - animals in a facotry are often treed with antibiotic ,w hich may increase the irsk of antiiotic resiance to bacteria .
Disadvanatge of factory farming (2)
-Crowded conditoins cause the chicens to be more stressed and gifht .
Ethical Objections to Factory Farming (1)
-Animals should be raised in anutral condtions ,a dn should be bale to enage in normal bheavoiur .
(free rnage ends can eat isnects , but facotry farming cannot ).
Ethical objections against factory farming ?
Enganging in anturla behaviour increases the animals welfare e.g reducing stress.
