Question

You sample a stream at site B and your boss wants you to make sure you sample for enough days to have confidence in understanding the richness of the species there. You find that following 20 days of sampling your cumulative species richness is 50 and had increased by one new species for every 5 days after the tenth day of sampling. Draw a graph that depicts this scenario and explain why you would continue sampling or not.

Answer 1

A practical problem arises when we measure species richness and its diversity is determining when you  have done sufficient collecting to stop sampling or to know when you've got species that matter. A good technique is to generate a cumulative species/ sample curve which plots the cumulative number of species collected( y axis) VS the number of sample collected (x axis). This technique assumes that initially you will be collecting new species with each subsequent sample, but after a while you will be collecting the sample species you have already collected in previous samples. Thus, you will get a curve that starts to flatten out once the curve levels off there will be no need to sample further.