NANFA-L-- Diversity Indicies

Todd D. Crail (tcrail at UTNet.UToledo.Edu)
Thu, 29 Sep 2005 08:34:30 -0400

Hi gang,

I'm trying to illustrate diversity using the good ol' Shannon, Simpson, etc.
While they're working out pretty well, I think I can take my data a step
further if there's an index that weights the presence of certain species.

For example:

I might sample Langenderfer Ditch where I caught 52 bluntnose minnows, 15
redfin shiners, 23 johnny darters and 10 orangethroat darters.

I might then go to the Tippecanoe River and sample 52 bigeye chub, 15
hogsucker, 23 bluebreast and 10 spotted darter.

Ignoring the fact that these would never be replicates as this is a quick,
pre-coffee illustration... :)

My current indicies would score these sites the same. I believe there is a
little more information in this data however.

Is there an index that places weight on certain species? I've caught rumor
of such things (mainly concerning plant heritage data through TNC), I
wondered if anything existed for our fishes?

It's never too late to have a happy childhood.
/ This is the discussion list of the North American Native Fishes
/ Association (NANFA). Comments made on this list do not necessarily
/ reflect the beliefs or goals of NANFA. For more information about NANFA,
/ visit Please make sure all posts to nanfa-l are
/ consistent with the guidelines as per
/ To subscribe, unsubscribe, or get
/ help, visit the NANFA email list home page and archive at