2.5: investigating ecosystems (NOT DONE)

Question 1

a method to determine the population size & factors that could impact its accuracy -

Answer 1

capture–mark–release–recapture / Lincoln index

• the number of trials carried out
• type of traps/bait used for catching the organism
• type of marking used to identify captured organism (may increase predation)
• time for organisms to reintegrate after first capture
• size of samples trapped

Question 2

lincoln index -

Answer 2

• measures population size

formula:
N = n1 * n2 / m

where N = total population, n1= no. of animals captured on day 1, n2 = no. of animals recaptured, m = no. of marked animals recaptured.

Question 3

simpson’s diversity index -

Answer 3

• measures species diversity

formula:
D = N ( N - 1 ) / ∑ n (n-1)

where N = total no. of organisms of all species @ a given site (total population)
& n = total no. of organisms of a particular species