B15 Biodiversity and pollution Flashcards
What is biodiversity?
The variety of different species of organisms on
Earth or within an ecosystem.
Why are ecosystems more stable when there is high biodiversity?
Reduces the dependence of one species on another for food, shelter and maintenance of the physical environment
Name an ecosystem that has high biodiversity?
Deciduous woodland
Tropical rainforest.
Name an ecosystem that has low biodiversity?
Arctic
Desert
Name three sources of water pollution
Sewage
Fertilisers
Toxic chemicals
Describe the effects of adding fertiliser or sewage into water
Sewage/fertiliser contains high concentrations of minerals eg nitrates
Causes aquatic plants to grow quickly (algal bloom)
Blocks light getting to lower plants
Plants die and sink
Decomposers/bacteria numbers increase to decompose the dead material
Reduces oxygen concentration in water
Fish and other animal suffocate
Describe the effects of burning fossil fuels on the atmosphere
Increases amount of carbon dioxide
Releases sulfur dioxide and nitrogen oxides
Releases smoke
Describe how increasing carbon dioxide in the atmosphere can
affect plants and animals
Leads to global warming
Change in rainfall
Increase in temperature
Loss of habitat
Increased compeition
Migration of animals towards poles
Describe how adding smoke to the atmosphere can affect plants and animals
Causes the formation of smog
Covers leaves in layer of dust
Reduces amount of light reaching the ground
Reduces photosynthesis as less light absorbed
Causes breathing difficulties
Describe how adding acidic gases to the atmosphere can affect plants and animals
Releases sulfur dioxide and nitrogen oxides
Leads to acid rain
Decreases the pH of streams, rivers and lakes
Results in death of aquatic plants and animals
Describe the effects of adding toxic chemicals to water
Kills plants and animals in the water
Increases competition for food
Reduces water availability for humans
Name two sources of pollution on land
Landfill
Toxic chemicals
Give 4 ways in which human reduce the amount of land available for other animals and plants
Quarrying
Building
Faming
Dumping waste
Name the ecosystem shown in the photograph
Peat bog
How is peatbog ecosystem destroyed by human activity?
Peat is cut and dried for human use
What is peat used for?
Peat compost
Fuel
What effect does burning peat have on the environment?
Reduces the biodiversity
Fewer plants, animals and microrganisms present
Burning peat releases carbon dioxide into the atmosphere
State what is happening in the photograph
Deforestation
Why are trees cut down in tropical areas?
Provide land for cattle
Provide space for rice fields
Grow crops for biofuels
Deforestation increases the amount of carbon dioxide in the atmosphere.
Give three reasons why.
Burning
Increased decomposition by microbes
Less photosynthesis
Name two greenhouse gases
Methane
Carbon dioxide
Name two human activities that increase the amount of
carbon dioxide in the atmosphere?
Burning fossil fuels
Deforestation
Name two human activities that increase the amount of methane in the atmosphere?
Growing rice in paddy fields,
Intensively farming cattle.
Give 3 consequences of global warming
Melting ice caps
Rising sea levels
Flooding
Climate change (changes in rain fall, temperature)
How might increased temperatures, caused by global warming, impact
animals
Aminol migration towards poles to find habitats with suitable temperatures
Tropical diseases become more common in areas such as Europe
Loss of habitat (eg ice caps)
Species may become extinct
How might flooding, caused by global warming, impact animals and plants
Low lying areas flooded
Habitats destroyed.
Increased competition for resources
What programmes are in place to increase biodiversity?
- Breeding programmes
- Protection and regeneration of of rare habitats.
- Reduction of deforestation by some governments
- Reduction of carbon dioxide emissions by some governments
- Reintroduction of field margins and hedgerows on farm land
- Recycling resources
Describe how the introduction of hedgerow and field margins can increase biodiversity on farmland
Increased number of plant species added to ecosystem
Increased number of animal species
Increasd number of predators to remove pests from crops
How does recycling resources increase biodiversity?
Fewer resources needed by increasing human population
Reduced use of landfill sites
Less pollution from landfill sites
