B18 - Biodiversity and Ecosystems Flashcards
1
Q
What is biodiversity
A
The variety of all the different species on earth or in an ecosystem
2
Q
Advantages of a high biodiversity
A
- Makes an ecosystem stable + more resilient to environmental changes
- Ecosystem is less dependant on only one species
- This could be for food or shelter
- If the population of a species falls, it won’t affect the whole ecosystem
3
Q
Reasons for deforestation
A
- To grow rice fields or for cattle grazing
- The grow crops to be used to make biofuels
4
Q
Ways deforestation impacts the environment
A
- Burning trees releas CO2
- Decomposing trees release CO2
- Lack of trees reduces absorbtion of CO2
- Loss of biodiversity
5
Q
What has the population increase lead to?
A
- Increased use of Earth’s resources
- More waste products
6
Q
How is water pollution caused and its effects
A
- Sewage contain huamn excretemnt is released into rivers or streams
- Fertilisers from farms
- Toxic chemicals from factories
- This kills aquatic organisms - reduing biodiversity
7
Q
How is air pollution caused and what are its effects
A
- Burning fossils fuels can cause acid rain
- Also releases large particulates which are pollutants
- This kills animals and plants and reduces biodiversity
- Also causes global dimming and health issues
- Carbon dioxide - global warming, changing migration, extreme weather, loss of habitat
8
Q
How is land pollution caused and what are its effects
A
- Waste dumped in landfills - reduces habitats
- Toxic chemicals e.g. heavy metals pollute soil killing organisms
9
Q
Steps in eutrophication
A
- Nitrates get in water
- Leads to algal bloom
- PLants beneath die from lack of light
- Algae then die
- Bacteria decompose algae and use up oxygen
- Fish and organisms die
10
Q
What is bioaccumulation
A
- Chemicals get into the food chain
- Chemical remain in animals tissues
- Over time, chemical levels will increase as they take in more
11
Q
What is biomagnification
A
- The concentration of chemicals increases in tissues of organisms as you move along a food chain
- Affects top predators the most
12
Q
How do humans reduce land available for organisms
A
- Infrastructure
- Farming
- Quarries
- Landfill
13
Q
What is peat and what are its advantages
A
- Dead plant material that hasn’t decayed due to acidic conditions in bogs
- They trap CO2
- Provide a habitat for lots of unique organisms
14
Q
What is peat used for and disadvantages of this
A
- Used for cheap compost
- Burned to produce electricity or for heat
- This reduces biodiversity
- Peat decays once extracted releases CO2
- Burning peat also releases CO2
15
Q
Biological consequences of global warming
A
- Loss of habitats
- Bleaching of sea corals
- Animals extend range to originally cooler areas
- Migration patterns changing
- Crops can’t be grown in too hot conditions