Sampling Methods

Do you remember all the sampling techniques we used to sample the habitat at the Braunton Burrows sand dunes on our lovely fieldtrip back last summer!? Well hopefully you do!!!

When sampling a habitat, there are 3 things we need to find out:
1. What species are present
2. The abundance of each species present
3. The distribution of each species

Organisms are distributed unevenly in most environments, so random sampling is ised to determine the number and abundance of species present. Also random sampling eliminates bias.
QUADRATS
- can find percentage cover by looking at the proportion of the quadrat's area occupied by a species
- can find species density by counting the number of individueals present and calculating the mean number per quadrat
- can find species frequency by looking at the proportion of quadrats with a particular species in them

POINT QUADRATS
- each species that touches a pin is recorded, together with the total number of times it is touched
- a point quadrat has to be randomly positioned

LINE TRANSECTS
- all species touching a line are identified and their position that touches the line recorded
- suitable for habitats with gradations in conditions

BELT TRANSECTS
- quadrats are placed sequentially along a line transect, making the transect wider