This chapter provides some metrics for measuring species diversity, the most basic
and important diversity component in ecological studies. The metrics for species diversity
covered only some common used ones in this book, like Shannon and Simpson indices. The
closed forms for computing the variance of the relevant indices are also provided. Typical
methods for the extrapolation of species richness are also mentioned in the text.
Keywords: Ecological indicators, ecosystem functioning, extinction risk,
functional diversity, functional redundancy, functional traits, molecular
information, phenotype, statistical ecology.
