Human influences on the ecosystem Flashcards
(43 cards)
Give 4 ways that modern technology has aided food production.
- New efficient machines can work over large areas
- Improved fertilisers to boost crop yield
- insecticides prevent crops from being destroyed by insects
- Herbicides stop competition from weeds for resources
- Desirable features chosen through selective breeding
Give one reason why monoculture is so bad for the ecosystems.
Monoculturre reduces diversity sidnificantly.
State the negative impacts of intensely farming livestock.
- Water pollution
- Soil and land quality is decreased
- Reduction in biodiversity
State 2 social issues with providing sufficient food for a growing human population.
- Land used for agriculture could be used for housing or leisure facilities
- Machinery used for agriculture can be loud and may become an issue for people who live nearby
State 2 economic issues with providing sufficient food for a growing human population
- Some less economically developed countries may not be able to establish efficient food production infrastructure
- More people will be living in harsher climates and therefore the cost of staple foods as imports will be greater
State 2 environmental issues with providing sufficient food for a growing human population.
- Farming equipment and processing facilities can produce extra greenhouse gas emissions
- Monoculture decreases biodiversity
State 4 factors that can lead to famine
- Natural disasters (flooding/drought)
- Unequal distribution of food
- Rapidly increasing population
- Poverty
Describe 3 human activities that cause habitat destruction.
- Deforestation for timber production, housing and farming
- Extraction of natural resources requires clearing land and large machinery
- Marine pollution from oil spills, waste, eutrophication and plastic waste is damaging to aquatic life and the habitat they live in
Describe how sewage in waterways can affect aquatic life.
Microorganisms that decompose sewage will use up the oxygen in the water so that there is not enough oxygen left for respiration for other aquatic organisms
Give 4 undesirable effects of deforestation
- Extinction
- Erosion of soil
- Increased risk of flooding
- Increased atmospheric carbon dioxide
Explain how deforestation causes extinction (Higher/Supplement)
- Deforestation removes food and shelter for animals
- Animals without food or shelter are less likely to survive, leading to extinctions
Explain how deforestation leads to soil erosion
- Tree roots anchor soil and the trees shelter and protect the soil which prevents erosion
- Deforestation leaves the soil exposed and erosion happens more quickly
Explain how deforestation leads to an increased risk of flooding
- Trees absorb water which evaporates off their leaves, leaving the ground drier and able to absorb more water
- Less trees increases surface runoff and the risk of flooding
Explain how deforestation leads to increased carbon dioxide levels
- Trees take in carbon dioxide from the atmosphere during photosynthesis which decreases atmospheric carbon dioxide levels
- When trees are cut down, the atmospheric carbon dioxide is no longer absorbed and so level remain higher
State 5 sources of water pollution
- Insecticides
- Herbicides
- Sewage
- Waste (plastics, chemicals, metal)
- Nuclear fallout
State 4 sources of air pollution
- Vehicle exhaust
- Home heating
- Industrial fossil fuel burning for generating power
- Manufacturing processes
State 4 sources of air pollution
- Vehicle exhaust
- Home heating
- Industrial fossil fuel burning for generating power
- Manufacturing processes
State 4 sources of land pollution
- Agriculture
- Improper handling of waste
- Sewage leaks
- Industrial pollution (chemicals, paints, plastics)
What is eutrophication?
An excess of nutrients in a body of water, often due to fertilisers in the water source
Why is eutrophication bad for aquatic life?
It causes an ‘algal bloom’ which decreases oxygen supplies in the water and degrades the water quality
Describe the process of eutrophication (
- Often caused by leaks of fertilisers containing nitrate and other ions into the water source
- Increased growth of producers (e.g. algae which is called an algal bloom)
- Increased decomposition after death of producers (due to lack of light) by decomposers which use up dissolved oxygen during respiration
- Organisms that need the oxygen in the water begin dying
What is meant by non-biodegradable waste?
Waste which cannot be broken down naturally in the environment (e.g. by erosion or decomposers)
Describe the effects of non-biodegradable plastics
- Chemicals in the plastics can leach out and cause damage to organisms
- Animals can get trapped in plastics, leaving them vulnerable (e.g. to predators or starvation)
- Animals can swallow plastics, causing blockages and often death
State 3 sources of methane in the atmosphere
Biomass burning
- Livestock production systems
- Decaying matter in landfills
