B17 biodiversity and ecosystems Flashcards
what is biodiversity
a measure of the varieties of the different species of organisms on earth.
what does the future on human survival, depend on
a good level of biodiversity
what does a good ecosystem rely on
high biodiversity
why has the human population grown so fast.
we have no natural predators, have found cures to diseases and learnt how to grow more food than the wild has to offer.
how do humans effect land and resources
we take up land for houses, farming and quarries reducing biodiversity as we destroy other animals habitats
what are finite resources
resources that will eventually run out
what happens if we do not manage our waste properly
our water may become polluted by sewage and fertilisers and the air may become polluted by poisonous gases
what is bioacccumilation
where more and more toxins enter the bodies of animals, leading to dangerous levels of poisons building up in top predators
how does pollution occur on land
landfill sites which also cause loss of habitats, and from toxic chemicals such as pesticides and herbicides which get into the soil and can be washed into rivers and streams
how is water polluted
farmers use fertilisers containing nitrate which easily wash into streams and rivers. Untreated sewage is then washed out into the sea, with high levels of nitrate.
What happens as a result of algae growing quickly in the sea (due to nitrate levels)
some plants die as there is too much competition for sunlight. This causes an increase in decomposers eating these dead plants, and they respire a lot lowering oxygen levels in water. This means there is not enough oxygen for many fish to survive
what can happen to large carnivores due to bioaccumilation
many die or fail to breed
how do we monitor pollution in water
bio indicators
what is a bio indicator
an organism whose presence indicate pollution levels
how is acid rain produced
fossil fuels burnt in vehicles and factories forming acidic gases, releasing Co2 into the atmosphere. Fossil fuels contain sulfur impurites, which react with oxygen while burning to form sulfur dioxide. Sulfur dioxide dissolves in rainwater, forming acid rain.
