B18 Flashcards
whats biodiversity
variety, diff species, ecosys
high biodiv = …
high stability
how do humans reduce biodiv
deforestation, pollution, clim change
why are we alive?
top of food chain, grow enough food, no diseases
why do we use land?
housing, agriculture, waste
what happens if waste isnt treated properly
leads to bad chemicals and parasites
why are landfills bad
take space, destroy habitats, toxic chems from waste to soil
problems with herbicides:
kill animals
what happens in each stage of the food chain in terms of chemicals
there is more and more buildup, this is called bioaccumulation
what is eutrophication?
eutrophication - the excess nutrients from land run-off of pesticides, herbicides, fertilisers
these run off into water sources
which increases nitrate conc.
which stimulate algae growth
these algae block out sunlight, stopping photosynthesis and oxygen
there is then too much competition for sunlight
plant biodiversity is lost
why does eutrophication lead to dead lakes?
because there is an increase in microorganisms feeding on plants that die
more decomposers = less oxygen
no oxygen = no animals = dead lake
what is a bioindicator
an animal that can be used to asses quality of environment
how is acid rain caused
burnt fossil fuels = acid gases
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these react with o2 to make sulphur dioxide which then dissolves in rainwater to make sulfuric and nitric acid
what are the effects of acid rain?
kills a bunch of stuff (leaves, plants, roots)
poisons water stuff (lakes, rivers)
how can we solve the acid rain problem?
burn less gases, lower sulphur fuels, biofuels
