Practical skills

Question 1

Name 4 sampling techniques

Answer 1

1. Point sampling
2. Transect (line and belt)
3. Quadrat sampling
4. Mark and recapture (aka capture-recapture)

Question 2

What is point sampling

Answer 2

Point sampling is a technique where individual points are chosen on a map (using a grid reference or random numbers applied to a map grid) and the organisms are sampled at those points.

Question 3

What are line transects?

Answer 3

A line transect is a sampling line placed across a community.
- used to determine changes in community composition (species distribution) along an environmental gradient.
- Line transects are drawn across a map, and organisms occurring along the line are sampled.
- A line transect uses a tape or rope to mark the line, and the species occurring on the line are recorded.
- The line(s) can be chosen randomly, or may follow an environmental gradient (such as a rise in altitude).

Question 4

What is Quadrat sampling?

Answer 4

A quadrat is a sampling method that allows you to estimate the number and variety of organisms in a large area by counting in a small area
- Quadrats are most useful in sampling immobile organisms such as plants or corals.
- Determine the size of the quadrat based on the size and abundance of the organism that you are sampling.
- The more quadrats you use, the more accurate your results will be.
- Very abundant organisms can be measured as a percentage of the area covered, rather than as a number of organisms.
- Photographing the quadrat can be a useful record-keeping method.

Question 5

Independent variable

Question 6

Dependent variable