Biodiversity and food security Flashcards
What is biodiversity?
The variety of living organisms in an
ecosystem.
How does fish farming impact biodiversity?
● Food used to feed the fish and waste can leak into water
sources, causing eutrophication
● Parasites from fish farms may spread and contaminate
surrounding ecosystems
● Other organisms may become tangled in netting
How does the use of fertilisers affect biodiversity?
Excess fertiliser can wash into water
sources causing eutrophication and death
of many species. This reduces biodiversity
Describe how fertilisers can cause eutrophication
- Fertiliser run-off into rivers and lakes
- Nitrates and phosphates build-up in water
- Algal bloom blocks sunlight
- Aquatic plants cannot photosynthesise ∴ less oxygen produced
- They die and decompose
- Decomposers further deplete oxygen levels
- Animals can no longer respire aerobically so die
How does the introduction of non-indigenous species
affect biodiversity?
● They may out-compete native species, causing a reduction in
population numbers
● Native species may become the prey of non-indigenous
species
● They may bring new diseases which could kill large numbers of
native species, reducing biodiversity
How can humans more positively impact
biodiversity?
● Protection of endangered species e.g. making hunting illegal,
breeding programmes increase population sizes
● Conservation schemes e.g. national parks, seed banks, zoos
● Reforestation
● Sustainable farming e.g. fewer pesticides
● Minimising global greenhouse gas production
What is reforestation?
Replanting forests to help restore
biodiversity
How do conservation schemes protect biodiversity?
They prevent species from becoming
extinct and increase population numbers,
maintaining biodiversity.
Outline the benefits of maintaining biodiversity
● Ensures future food requirements can be met, reduces damage to food chains
● Increases the likelihood of species adapting to future environmental change
● Many plant species are yet to be discovered and may contain chemicals that
could be used in future medicines
● Safeguarding valuable future resources e.g. fuels, paper
● Aesthetics - culture, ecotourism etc.
● Jobs provided by ecotourism, reforestation and conservation schemes
What is food security?
Ensuring that populations have access to
adequate amounts of safe and nutritious
foods
List the biological factors affecting food security (5)
● Rising human population ● Changing diets ● New pests and pathogens ● Environmental change ● Sustainability
Describe how the rising human population affects
food security
As human population increases, global
food production must also increase in
order to meet the growing demand for
food.
Describe how changing diets affect food security
● Greater consumption of meat and fish in wealthier populations
● Less energy and biomass available from livestock than crops
● Livestock use land for grazing and are fed crops that could
otherwise be used for human consumption
● Less food is available for humans therefore reduction in food security
Describe how new pests and pathogens affect food
security
Pests and pathogens can reduce or
destroy crop yields, negatively impacting
food security.
Describe how sustainability affects food security
● Unsustainable farming methods disrupt food chains, compromising
the ability to meet future food requirements
● Due to the high input costs, many LEDCs cannot maintain modern
farming methods
● Using land for biofuel production reduces land available for crops
