B7 - Ecology 2 Flashcards
What is biodiversity
Biodiversity is the variety of all the different species of organisms on earth, or within an ecosystem
Why is high biodiversity important
Ensures stability of ecosystems by reducing dependence of one species on another for food, shelter and maintenance of the physical environment
Give two reasons in which the population of the world is rising very quickly ( 2 marks)
modern medicine and farming methods - reduced the number of people dying from disease and hunger
Describe the three ways in which pollution can occur ( 3 marks)
in water - from sewage, fertiliser or toxic chemicals
in air - from smoke and acidic gases
on land - from landfill and from toxic chemicals.
What does pollution result to
Pollution kills plants and animals which can reduce biodiversity.
Name three greenhouse gases
methane
carbon dioxide
water vapour
Describe the consequences of global warming ( 6 marks)
Higher temperatures cause seawater to expand and ice to melt - sea levels to rise - flooding
Distribution of many wild animals and plant species may change as temperature increase
Change in migration patterns
Biodiversity could be reduced if some species are unable to survive a change in the climate - possible extinction
How do humans reduce the amount of land available for other animals
building, quarrying, farming, and dumping waste.
Give two reasons why deforestation is done
to clear land for farming
to grow crops for biofuels
Describe the problems that arise from deforestation ( 6 marks)
Less carbon dioxide taken in: - cutting down trees means that the amount of carbon dioxide removed from the atmosphere during photosynthesis is reduced
Trees ‘lock up some of the carbon that they absorb during photosynthesis in their wood, which can remove it from the atmosphere for hundreds of years
More carbon dioxide in the atmosphere: - carbon dioxide is released when trees are burnt to clear land
Microorganisms feeding on bits of dead eod release carbon dioxide as a waste product of respiration#
Less biodiversity: -habitat like forests can contain a huge number of different species of plants and animals, so when they are destroyed there is a danger of many species becoming extinct - biodiversity reduced
Why are peat bogs often drained
area can be used as farmland
Describe the problems that arise from destroying peat bogs
Plants in peat bog store carbon in the peat instead of being released into the atmosphere
When peat is drained, it comes into more contact with air and some microorganisms start to decompose it. Microorganisms respire, they use oxygen and release carbon dioxide
Carbon dioxide is also released when peat is burned as a fuel
Destroying bogs also destroys the habitats of some of the animals, plants, and microorganisms that live there - reducing biodiversity
Describe how biodiversity could be maintained (6 marks)
3 pro, gov, waste
Breeding programmes - set up to help prevent endangered species from becoming extinct
Programmes to protect and regenerate rare habitats like mangroves, heathland and coral reefs - protecting these habitats helps to protect species that live there - preserving ecosystem and biodiversity
Programmes to reintroduce hedgerows and field margins - provides habitat for wider variety of organisms
Government introducing regulations and programmes to reduce the level of deforestation taking place and amount of carbon dioxide being released into atmosphere
People encouraged to recycle to reduce waste that gets dumped in landfill sites - reduces amount of land taken over for landfill - leaving ecosystem in place
Describe the negatives of how biodiversity is maintained (6 marks)
cost x2 development
Protecting biodivesity costs money - government may pay farmers to reintroduce hedgerows and field margins in their land
Protecting biodiversity may come at a cost to local people’s livlihood - reducing deforestation may result in unemployment
Previously untouched land with high biodivesity has to be used for development e.g. for housing or agriculture
