effective_richness: Effective Number of Taxa

Description Usage Arguments Value


Effective Number of Taxa


effective_richness(taxa.wide, index)



Taxonomic counts aggregated at the specific taxonomic classification (e.g., Order, Family, or Genus) in a wide data format. Use the wide function to prepare the data.


Requires "shannon" (Shannon Wiener Diversity Index) or "invsimpson" (Inverse Simpson's Diversity Index).


This functions converts the common diversity indices values to effective richness, as outlined by Jost (2006). Effective richness is a richness value weighted by species evenness; the value represents the taxa richness of a perfectly even assemblage reuquired to produce an equivalent diveristy index value to the observed assemblage. Shannon Wiener Diversity is converted using the exponential function: exp(H') where: H'= Shannon Wiener Diversity

Inverse Simpsons Diveristy is converted using: 1/(1-(1/D)) where: D = vegan Inverse Simpson's Diversity Index (1/(sum(n/N)^2) ) n = the abundance of a particular taxon N = the total abundance of organisms

zsmith27/Benthos documentation built on May 5, 2019, 2:38 a.m.