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Flashcards in Human Influences on Ecosystems Deck (8)
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Acid rain

Acid rain:
- Causes: burning fossil fuels - contain impurities => sulfur dioxide + nitrous oxide are formed and dissolved in rainwater to produce acid rain
- Effects: leads to death of organisms. Acidification of lakes and rivers
- Solutions:
+ Catalytic converter
+ Low sulfur fuels
+ Chimney gas desulfurisation



- Fertilisers leach into the water surroundings
- It encourages growth of algae
- Algae grows and covers the surface of wtaer
- Sunlight is blocked and cannot reach the plants underneath
- Plants die because they cannot perform photosynthesis
- Decomposers such as bacteria feed on the dead
- Level of oxygen decreases because they use it to respire and reproduce
- Organisms are killed due to low concentration of oxygen



- The removal of large areas of forest to provide land for
farming and roads, and to provide timber (wood) for building, furniture and fuel.
- Effects:
- Reduction of habitats or food sources for animals, which can result intheir extinction. Animal and plant diversity is reduced, and food chains are disrupted.
- Desertification can eventually occur.
- Lack of roots and soil => flooding and mudslides. .
- Less CO2 is absorbed from the atmosphere, more
CO2 build up à increase the greenhouse effect.


Environmental Pollutants

1.12.14 the table


Discuss the effects of non-biodegradable plastics in the environment

- Cannot be decomposed
- Aquatic animals may suffer from choking it or being entangled
- Relase toxins => adverse effects
- Block light for photosynthesis
- May block flow of water => reduce concentration of dissolved oxygen


Explain how increases in greenhouse gases (carbon dioxide and methane) are thought to cause global warming

- Solar radiation passes through the atmosphere and warms the Earth's surface
- Earth radiates heat energy back into space (mainly infra-red radiation)
- Heat energy is absorbed by greenhouse gases => global warming => rising sea levels in the Arctic and Antarctica => flood and natural disasters


Describe the need for conservation of:
• species and their habitats
• natural resources (limited to water and nonrenewable
materials including fossil fuels)

- Ecosystems help to maintain the balance of life on the planet
- Provide food and fuels, substances such as medicines
- Wide variety of organisms => diversity


Sewage treatment

- Primary treatment: remove large solids (filter or screens)
- Secondary treatment: use microbes and bacteria to decompose organic materials with aeration or trickle filter
- Tertiary treatment: remaining organic materials from sludge => sludge settles and water leaves plants. Treated with chlorine/ozone => collection of water from evaporator