What is a rarefaction curve and how to interpret it?

A rarefaction curve is used to present relationship between number of OTUs and number of sequences. It can show species richness from sampling results. A

  • If the curve reaches plateau, it means that with more sequences, the gain of newly discovered OTUs is limited. The sequencing depth may be sufficient.

  • If the curve still increases fast, it means the sequence depth are not enough and more species will be discovered with more sequencing efforts.