B17 - Biodiversity And Ecosystems Flashcards
Ecosystem
The interaction of a community of living organisms with the non-living parts of their environment.
Biodiversity
The variety of all the different species of organisms on earth, or within an ecosystem.
Why is biodiversity important?
Ensures the stability of ecosystems by reducing the dependence of one species on another.
What are organisms dependent on each other for?
For food, shelter and the maintenance of the physical environment.
What is extinction?
When there are no more living members of a species left.
Why is it important to prevent the extinction of a species?
They may provide useful substances to
humans, the extinction may effect another species in the food chain, there is a duty to preserve species for future generations.
Why is more waste being produced?
More people, increase in standard of living
Where can pollution occur?
• In water, from sewage, fertiliser or toxic chemicals
• In air, from smoke and acidic gases
• On land, from landfill and from toxic chemicals.
What can end up in water, which causes pollution?
Sewage, fertiliser or toxic chemicals
What problems does carbon dioxide cause?
Greenhouse effect and global warming
What problems can nitrogen oxide and sulfur dioxide cause?
Acid rain.
What problems can acid rain cause?
Damage trees, lower pH or lakes and rivers, damage stone and metals.
What causes smog?
Tiny particulates in smoke.
What chemicals from farmland pollute water?
Pesticides, herbicides, fertilisers.
How can toxic chemicals end up in the water supply?
Released illegally by industry.
What happens when fertilisers end up in the water supply? (potential 6 marks)
-Large growth of algae,
-death of algae,
-microbes decay waste,
-increased respiration by microbes,
-decreased oxygen in water,
-organisms living in water die from lack of oxygen.
What is put in landfill?
Any rubbish that is not recycled.
Human use of land
Building, quarrying, farming, disposing waste.
Why is demand for land rising quickly?
More people and increased standard of living
What are bogs?
Wet areas of land without trees with lots of moss growing in them.
What are the conditions in bogs like?
Acidic and low in nutrients.
What is the bog made from?
Partially-decayed plants.
Why is peat a non-renewable resource?
It takes a very long time to form.
What is peat used for?
Burned as fuel, or added to soil by gardeners for fertiliser.
Why does peat release carbon dioxide when it is added to the soil?
-Mixed with oxygen
-Microbes begin to break it down, they respire as they do, releasing carbon dioxide.
Why has deforestation occurred?
Provide land for cattle and crops, grow crops for biofuel, to provide materials for building, fuel and paper
Why has deforestation increased in more recent years?
Increased population and development of large industrial machinery
Why is deforestation reducing biodiversity?
It is destroying habitats and kills different species.
Why does deforestation increase soil erosion?
Roots stop holding the soil in place and so it gets washed and blown away
How does deforestation affect atmospheric composition?
Increases carbon dioxide as there is less photosynthesis and more burning.
Consequences of global warming
Melting ice caps, rising sea levels, expansion of seawater, flooding of land, more extreme weather, changes in weather patterns, habitats changing, migration patterns changing, extinction.
Explain why it took a while for the theory of global warming to be accepted by most.
Lack of evidence, more evidence now collected, which has been peer reviewed.
Describe the different ways that humans have a negative impact on ecosystems.
Increased waste and pollution, destruction of peat bogs, use of land for farming, building, quarrying, dumping waste, deforestation, increased air pollution.
Describe the different ways that humans have a positive impact on ecosystems.
Breeding programs, protection of rare habitats, reintroduction of field margins, reducing deforestation, recycling materials.
Explain how we can reduce the amount of waste going to landfill.
Reduce
Reuse
Recycle
