Ecosystems and material cycles Flashcards
What are the 5 steps of eutrophication?
- Fertilisers enter the water, adding excess nitrates
- The excess nitrates cause algae to grow quickly, blocking out light
- Plants can’t photosynthesise, die and decompose
- With more food available, microorganisms that feed on decomposing plants increase and use up all oxygen
- Organisms can’t respire and die
What does individual mean in terms of an ecosystem?
A single organism
What does population mean in terms of an ecosystem?
All the organisms of one species in a habitat
What does community mean in terms of an ecosystem?
All the organisms of different species living in a habitat
What does abiotic mean?
A non living factor
Eg. Temperature, light intensity
What does biotic mean?
A living factor
Eg. Competition, predation
What does interdependent mean?
Describes how individual species are dependent on each other for resources
What is biodiversity?
The variety of living organisms in an ecosystem
What is an ecosystem?
A community of organisms along with all the non living conditions
What are the 3 steps of using a quadrat?
Put it on the grass
Count/identify species
Multiply the numbers
How do you multiply using a quadrat?
Work out the mean per metres squared, then multiply the mean by the total area of the habitat
What are the 3 steps to using a belt transect?
- Mark a line in desired area
- Collect data using multiple quadrats lined up
- Repeat several times and find mean
What is the advantage of using a belt transect?
A clear gradual change can show how abundance changes with it and the effect of the factor on the different plant species
What is the disadvantage of using the belt transect?
Species which don’t fall on the line or in the belt may be missed and therefore the sample is not representative
What are the positive human impacts on biodiversity?
Reforestation
Conservation schemes
What are the negative human impacts on biodiversity?
Eutrophication
Fish farming
How can humans reduce biodiversity?
No indigenous species
What are the benefits of reducing biodiversity?(4)
- protects human food supply
- minimal damage to food chains
- future medicines
- ecotourism
What are the 7 steps of the water cycle?
Condensation Precipitation Evaporation Transpiration Surface run off Percolation Groundwater run off
What is condensation in the water cycle?
When watervapour creates a cloud
What is precipitation in the water cycle?
Rain
What is evaporation in the water cycle?
Water turns into a gas
What is transpiration in the water cycle?
Watervapour removed through plants
What is surface run off in the water cycle?
Water runs off ground
What is percolation in the water cycle?
Water moves into ground
What is groundwater run off in the water cycle?
Water goes underground
What are the 7 steps of the carbon cycle?
Photosynthesis Food chains Animal respiration Plant respiration Combustion Death Respiration of composers
How do plants take in nitrates? (4)
- active transport
- through root hair cells
- low to high (soil to root hair cell)
- using energy for respiration
What can lightning do in the nitrogen cycle?
Make oxygen react with nitrogen to make nitrates
What do fertilisers do to the nitrogen cycle?
Increase crop yield
What does nitrogen fixing bacteria do?
Converts nitrogen gas into nitrates
Where does nitrogen fixing bacteria live?
Soil/root nodules/legumes
Why is the nitrogen cycle mutualistic?
Bacteria gets glucose
Plant gets nitrates
What do food chains do in the nitrogen cycle?
Proteins/amino acids from organisms used by consumers to make more proteins
What do decomposer bacteria do in the nitrogen cycle?
Turn ammonia into nitrates
What does nitrifying bacteria do in the nitrogen cycle?
Break down protein from dead plants into ammonia
What does denitrifying bacteria do in the nitrogen cycle?
Turn nitrates from soil into nitrogen gas in the air
What is crop rotation?
Different nitrogen fixing crops are grown each year in a cycle putting nitrates into the soil for the crop to use the following year
How do fertilisers increase the amount of nitrates in the soil?
They recycle nutrients and return them to the soil through decomposition
