Functional diversity index (FDvar)
FDvar measures the variance in the log-transformed attribute values of the species present at a site, weighted by relative abundances.
Mason Norman W.H., MacGillivray Kit, Steel John B., and Wilson J. Bastow1
Journal of Vegetation Science 14, 2003, pp 571-578.
From 0 to 1
It is designed to work with one character at a time.
Unaffected by whether two sibling (and functionally equivalent) species in a genus are combined or kept separate, so long as an additive measure of abundance is used. It is not affected by the number of species .
This index is analogous to the evenness index Evar of Smith & Wilson (1996)
R Package description
Studies that used this index
Smith, B. & Wilson, J.B. 1996. A consumer’s guide to evenness indices. Oikos 76: 70-82.