4.5c- pyramids

- to quantify the number of consumers per tropic level, we use a pyramid of number
- for example, 1000 carrot plants, 100 carrot flys, 10 fly catchers and 1 sparrow hawk
- this can be turned into a diagram used to illustrate this
- it must be made clear how large the organism it represents is i.e. a tree. this is because you cannot start with a small amount of energy and end with a large amount
- another method is the pyramid of biomass bio= living, mass= amount (g/km)
- a pyramid of biomass is based on the amount of dry mass in a organism
- this method is difficult because everything must be dryed out first
- the third is the pyramid of energy transfer
- this cannot be inverted
- units of enery are used (joules, kilajoules)
- units of area (m) and units of time (s/mins)
- pyramid of number is the easiest pyramid to use because the pyramid of energy is very time consuming