biodiversity & the effect of human activity on the environment TOPIC 7 (paper 2) Flashcards
define biodiversity
the variety of different species or organisms that live within a specified geographical area
what areas have high biodiversity
- oak woodlands
- tropical rainforests
what areas have low biodiversity
- deserts
- polar regions
why is high biodiversity important
- indicates the ecosystem is stable ~ reduces the dependance of one species on another for food
- helps maintain the correct physical envrionment
- ensures the survival of the human population
give some human activities which cna reduce biodiversity
- deforestation
- waste production
- global warming
why is the human population growing rapidly
- improved medicine
- imporved farming techniques
as the human population grows what pressure does this put on the environment
- increased demand for reasources
- higher standard of living = demand for luxary
- increased use of raw materials
why is more waste being produced
- increase in standard of living
- means more reasources are used
what is a major effect of waste produce
if it is not handled properly it results in more pollution
what are the three types of pullution
- land
- water
- air
how is water polluted
- from sewage
- fertilisers
- toxic chemicals
how is air polluted
- smoke
- acidic gases
how is land polluted
- ladfill
- toxic chemicals
- nuclear waste
what is a landfill site
a site for disposal of waste materials by burial and the oldest form of waste treatment
what are the problems with landfill sites
- attracts vermin ~ spread of communicable diseases
- as items break down they release toxic liquids and gases (methane, sulfur dioxide)
what is the management for land pollution
- reduce = cut down on amount of disposable products used
- reuse = use things again
- recycle = make new items out of waste meterials
what diseases can water pollution cause and spread (sewage)
- cholera
- salmonlella
- norovirus
describe the effects of chemical water pollution
- pesticides, herbicides can lead to bioaccumlation
- the concertration of toxins increases in each tropic level
- becomes deadly and can kill the higher consumers
what can water pollution from fertilisers lead to
eutrophication
describe how fertiliers cause eutrophication
- excessive nutrients from fertilisers are flushed into land
- plants like algea flurish
- algea bloods prevent sunlight from reaching other aquatic plants and water is oxygen depleated
- dead plants are broken down by decomposers which use up even more oxygen in water
- no oxygen for fish and other oragnisms so ecosystem dies
explain air pollution causes by acidic gases
- burning fossil fuels releases sulphur dioxide
- SO2 reacts with water vapour and sunloght to produce sulphuric acid
- falls on as acid rain, destroying limestone, plants and animal life
how long do peat bogs take to form
thousands of years
what are peat bogs
areas of land that are waterlogged and acidic
how are peat bogs formed
- areas saturated with water = less oxygen in soil
- dead plants dont decay properly
- partly rotting plats accumulate and form peat
- carbon in plant is stored in peat instead of into atmosphere when decomposers respire
- reduces the area of original habital
- reduces biodiversity
what do we do to peat bogs
- often drained to remove excess water so land can be used by farmers
- peat can be dug and dried to be used as fuel
- peat can be dug and sold to farmers for compost
what happens when peat bogs are drained
- more air is exposed to the top of the peat
- this exposes microorganisms in the soil to more O2
- partly decayed plants are further decomposed
- more CO2 is released to atmosphere as microoganisms respire
what is deforestation
the large-scale cutting down of trees
why does deforestation occur
- provide more land for farming = more food
- grow crops for biofues
- provide more living space
what are the environmental impacts of deforestation
- reduced biodiversity
- less CO2 removed from atmosphere
- less carbon locked up
- drier climates
- increased risk of flooding
- less fertile soils
- increases risk of erosion and landslides
what are the impacts of global warming
- rising sea levels ~ ice caps melt, loss of habitats
- changes in the distribution of animals ~ climates change so animals are less suited / more suited
- changes to migration patterns ~ warmer in some areas so dont need to migrate
- decreased biodiversity ~ species not able to adapt to climate change = death
how do we maintain biodiversity
- breeding porgrams ~ prevent extinction, increase gene pool
- protection & regeneration of rare habitats ~ peatlands, coral reefs, mangroves
- reintroduce field margins ~ restore natural biodiversity
- reduce deforestation and CO2 emissions ~ reduce rate of global warming
- recycling ~ reduce quantity of waste
what are the conflicting pressures of maintaining biodiversity
- financial costs ~ very expensive
- impact on local economy ~ lead to unemployment, and loss of industry
- protecting food security ~ pesticides and herbicides allows us to have more food
- development of society ~ land is needed for housing
