Human influences on the ecosystem Flashcards
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
What does excess atmospheric methane and carbon dioxide cause?
-Methane and CO2 are greenhouses gases
-Excess greenhouse gases lead to the
greenhouse effect where heat is trapped by the gases
-This leads to global warming
State 3 negative consequences of global warming
- Sea level rise caused by melting iceberg
- Disrupted farming and agriculture
- Increased spread of diseases in warmer climate
What detrimental impacts can sulfur dioxide have on the environment?
- Formed when fossil fuels containing impurities are burnt
- Sulfur dioxide can dissolve in water to form acid rain which can erode buildings and pollute water sources
State 3 negative effects of acid rain
- Acid rain accumulates in waterways, polluting water and harming organisms
- Acid rain damages plants and trees
- Acid rain erodes buildings and infrastructure
How is the amount of sulfur dioxide production reduced?
- Switch to renewable energy sources
- Sulfur dioxide can be removed from waste gases
- Sulfur impurities can be removed from fuels before they are burnt
How can the impact of acid rain be reduced?
Reduce the acidity of soil and water by adding powdered limestone or slaked lime
Explain how excess methane and carbon dioxide causes global warming
- The gases accumulate in the atmosphere and absorb the thermal energy from the sun
- This traps the extra heat energy in the atmosphere and warms the earth
Describe the negative impacts of female contraceptive hormones in water supplies
- Oestrogens can change the behaviour of fish by altering their genes
- Contraceptive hormones can cause male fish to produce eggs and can no longer reproduce (feminisation)
What is a sustainable resource?
A resource which is produced as rapidly as it is used up so that it does not run out
What is sustainable development?
Development to meet the growing needs of the human population without damaging the environment
Why is it necessary to conserve fossil fuels?
Because fossil fuels are non-renewable and so will run out with continued use
State 2 resources that can be maintained
⦁ Timber
⦁ Fish stocks
How can forests and fish stocks be sustained?
⦁ Teaching people about the need for conservation
⦁ Legal quotas that define a limit to the amount of fishing
⦁ Replanting trees when they have been cut down
⦁ Captive breeding programs
State 4 resources that can be recycled
⦁ Paper
⦁ Glass
⦁ Plastic
⦁ Metal
How can sustainable development be achieved? (
⦁ By managing conflicting demands (e.g. for resources by ensuring the use of resources does not damage the environment and resources are used in moderation)
⦁ By cooperating at local, national and international levels and implementing government schemes
Give 5 causes of extinctions
⦁ Climate change ⦁ Destroying habitats ⦁ Hunting/poaching ⦁ Pollution ⦁ The introduction of a foreign species
What are the risks to a species if the population size drops considerably?
⦁ A smaller population size means that there will be a smaller gene pool
⦁ A smaller gene pool means that the population are not able to adapt to change as easily and are at a higher risk of extinction
Give 4 ways that species can be conserved
⦁ Monitoring and protecting species and habitats
⦁ Teaching people about why species are going extinct and how to prevent extinction
⦁ Captive breeding programmes within zoos and wildlife reserves with the aim of increasing the population size before reintroduction into the environment
⦁ Seed banks to preserve genetic diversity
Why is conservation important?
⦁ It prevents the extinction of species
⦁ It protects vulnerable environments
⦁ It ensures that ecosystems can still provide useful resources like medicines and food
