4.5 c (Pyramids)

+ Producer -> 1 -> 2 -> 3 consumer = Basic/simple description on feeding in community.
+ Quantify Trophic Levels:
1. Pyramid of Number (count organisms at each level)
eg: 1000 leaves of carrot plant -> 100 carrot fly -> 10 fly catcher -> 1 sparrow hawk = *Pyramid* each level 1/10th of the size of the level before.
Problems: eg: 1 tree -> 100,000 Aphids -> 1000 Lady Birds -> 10 birds = In energy terms this is wrong, the size of tree to Aphids is wrong scientifically.
2. Pyramid of Bio Mass "living material mass"
Problems: Water level mass. Because this pyramid is based on "Dry Mass"  = better understanding of mass of matter
Disadvantages: need to work out dry mass of each level which is very difficult.
Pyramid should be shown in units of mass kg/g or unit of area m2/km2
3. Pyramid of Energy (ideal)(transfer of energy from 1 level to the next)
+ cannot be inverted (put upside down)
+ This type of pyramid measures efficiency too. eg: Sun Light 100% = 10% producer = 10% efficiency
+ Requires unit of energy (J/ kJ)
+ unit of area (m2)
+ unit of time (secs/mins/years)
+ however it is complex and time consuming.
++ Pyramid of number = popular
                   inbetween- Biomass = hard
Pyramid of energy = hard and complex       Progressing downwards in production of Pyramids.