Core Prac 10

Question 1

State the two sampling techniques that can be carried out in an ecological study

Answer 1

Random and Systematic Sampling

Question 2

State how to determine which method is appropriate based on the area of study (with examples)

Answer 2

Random - an area which has an even distribution of the species to be measured E.g. daisies in a field
Systematic - an area which has an uneven distribution of the species and abiotic factors e.g. clover species moving out of a woodland, increasing light intensity

Question 3

Devise a valid and reliable method for carrying out random sampling

Answer 3

• divide area into equal sections, and number
• randomly generate numbers
• use a quadrat in that area and collect data on abiotic and biotic factors
• repeat 10 times

Question 4

Devise a valid and reliable method for carrying out a systematic sample

Answer 4

• make a line transect along environmental gradient
• min 10 quadrats alongside at regular intervals
• collect abiotic and biotic data in each quadrat
• place 2 other line transects and repeat

Question 5

Explain how a frame quadrat can be used to estimate percentage cover of a species

Answer 5

Each square accounts for 4%, multiply by number of squares with more than half covered by a species (to estimate)

Question 6

Explain how a frame quadrat can be used to calculate species richness

Answer 6

Count number of different species within the quadrat