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What is a food chain?
• A diagram which shows the feeding relationships that exists between a number of organisms.
What is a food web?
• A diagram which shows the feeding relationships that exists between a number of organisms but is more complex.
GPP(Gross Product) =
NPP(Net) + Respiration
What is GPP?
CO2 used in PS
Biomass of glucose available at end of photosynthesis
What is NPP?
CO2 taken in to add to CO2 from respiration
Biomass in tissues and stores
What is respiration(equation)?
CO2 produced in respiration
Glucose used in respiration
What does the graph look like, for GPP = NPP- Respiration?
Why are plants so bad at converting light energy into GPP?
• Some energy is reflected from the surface of the leaf.
• Some energy is ‘transmitted’ – passes through the leaf without hitting a chloroplast.
• Some energy hits the chloroplast but can’t be used for photosynthesis
• After absorption by the chloroplast, some energy is lost as heat during photosynthesis.
Energy in Animals Equation
N = I - ( F + R )
N = Net productivity = biomass
I = input
F = faeces
R = respiration
How can we maximise productivity in farming?
1. Remove the competing consumers
2. Remove the competing producers using chemical and biological controls
3. Battery Farming!
Draw and explain the nitrogen cycle:
What does the phosphorus cycle show?
How phosphorus is recycled in ecosystems
Why do plants and animals require phosphorus?
in order to produce biological molecules such as PPLs (CM), nucleic acids (DNA/RNA) & ATP
What processes does the phosphorus cycle include?
Phosphorus in rocks is slowly released into the soil & into the water sources in the form of phosphate ions, by weathering
Phosphate ions taken up by soil by plants through their roots or absorbed by water by algae
Phosphate ions are transferred to consumers during feeding
Phosphate ions in waste products & dead organisms are released
What are Mycorrhizae?
What do they do?
associations between certain types of fungi and the roots of the vast majority of plants
increase the surface area and act as a sponge holding water and minerals.
plant can better resist drought and take up inorganic ions more easily.
Natural and artificial fertilisers are used to…
replace the nitrates and phosphates lost by harvesting plants and removing livestock.
What are the negative effects on the environment of nitrogen fertilisers?
include reducing biodiversity, leaching and eutrophication.
What is leaching?
mineral ions, such as nitrate, dissolve in rainwater and are carried from the soil to end up in rivers and lakes.
What is eutrophication?
Fertilisers are washed (leached) from farmland into lakes and rivers.
Algal growth at the surface of the lake is unlimited due to the high nutrient levels.
Competition for space results in lots of algal death.
Dead algae falls to the bottom of the lake and joins the sediment.
Bacteria decompose the dead plant matter.
Oxygen levels in the water decrease as the bacteria carry out aerobic respiration (A high Biological Oxygen Demand).
Fish die from lack of oxygen.
Light cannot reach the lower parts of the lake.
Plants on the lake bed die from lack of light.
Small invertebrates die from lack of oxygen.
Mammals and birds that rely on the lake for food die.
Note 
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