4.7

4.6

4.5c Pyramids

4.5b Food Chains

4.5a Food Chains

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4.4

4.3 quadratic samples

- Sample has to be random otherwise bias is introduced and results will not be accurate.
- It is a representative so it has to be large enough so our estimate is as accurate as possible

After you have randomly chose the square and counted species then repeat and randomly chose ten more coordinates.

After you have got all your data put it into a table and calculate the mean.

to get as close to accurate representative as possible the bigger the squares the better and try do 10 quadratics or 10% of actual area

4.2 Quadratics

The purpose of quadratics is to count the number of individuals in a population in a specific habitat.

Quadrating - based on squares
                   - used to sample an area an count the number on individuals in the quadratic
                   - from 1/2 metre squared to 1 metre square usually.
                   -  has to be repeated
                   - to estimate size of population of a species

4.1 defining ecosystem, habitat, population and community

Ecosystem = community of organisms within a habitat.

Community of organisms = all the populations of different species interacting by feeding.

Population = number of individuals of a particular species

Species = organisms that reproduce to give fertile offspring

Habitat = abiotic features such as temperature, rainfall, humidity, slope of land etc