PiscesLogoSmallerStill Alpha diversity

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The Alpha Diversity tab at the left of the program window displays a list of methods which can be run by clicking on their icon.

Comparative reviews of relative merits of the indices described below are provided by Taylor, (1978); Kempton (1979) and Magurran (2004). The program offers a choice of 11 measures of alpha diversity.


alpha diversity indices


The index for each individual sample is tabulated. At the bottom of the table the index and jackknifed standard error for all the samples combined is also shown.


Diversity output



Descriptions of these indices are available by following the jumps below.



Simpson's D

Species Number

Margalef D

Berger-Parker Dominance

McIntosh D

Brillouin D

Fisher's alpha

Q statistic

Menhinick D




The output from all of the diversity estimators is presented in similar fashion. In the first column is the name of the sample, and in the second the calculated value for the index. Remember that if you have chosen to subset the data then only the samples selected will be represented in the output. If the Bootstrap function is used, then the results will be displayed in the third and fourth columns. The change in diversity between samples can also be shown graphically, simply click on the Graph tab to display the chart.


To export or print the data see 'Printing and exporting your results'.


To print the indices, click in the window to activate it, then choose File: Print on the top menu bar, or right-click in the results window and select Print from the pop-up menu.