required practical 12: investigation of named variable on the distribution of a given species

Question 1

how can you investigate the effect of an environmental factor on the distribution of a species (random sampling in 2 areas)

Answer 1

divide 2 areas into grids
generate coordinates using a random number generator
place quadrat and count number of animals in quadrat
repeat more than 10 times
calculate a mean for both areas

Question 2

why is % cover used instead of frequency

Answer 2

organisms are too small to count, too hard to count all the organisms

Question 3

why is random sampling used

Answer 3

to avoid sampling bias

Question 4

why is a large sample used

Answer 4

to minimise the effect of anomalies, ensures the sample is representative of the population