Graphing The Data: Species Accumulation Curves
Ecologists often need to determine the number of species in an area they are sampling. As we have discussed in this chapter, they can use an equation to estimate the total number of species or they can graph a species accumulation curve that plots the sample size along the x axis and the number of species observed along the y axis. Using the data in the table, graph species accumulation curves for forest communities A and B.
Based on your graph, which community has been sampled sufficiently to provide a good estimate of the species richness that exists and which community requires more sampling? Explain your answer.
| NUMBER OF INDIVIDUALS SAMPLED | NUMBER OF SPECIES OBSERVED IN COMMUNITY A | NUMBER OF SPECIES OBSERVED IN COMMUNITY B |
|---|---|---|
| 20 | 12 | 5 |
| 40 | 20 | 10 |
| 60 | 27 | 15 |
| 80 | 33 | 19 |
| 100 | 38 | 23 |
| 120 | 42 | 27 |
| 140 | 45 | 30 |
| 160 | 47 | 33 |
| 180 | 48 | 36 |
| 200 | 48 | 38 |
