Biodiversity within a species

Why is sampling used?

To determine the species richness and species evenness in a community.

Random sampling

• Trying to obtain a representative sample by using random selection.

• Decreases bias but may have low reliability as may not be typical of whole habitat.

Example of random sampling

• Area of habitat (coordinates) selected using random numbers.

Non random sampling

• opportunistic: select organism that are readily available, may not be representative.

• stratified: population divided into sub-groups e.g males and females. May not be representative so must ensure values are equal.

• systematic: gradual change in habitat from one place to another. Line transect or belt transect.