This paper addresses the need for an internationally accepted definition of biodiversity the lack of
which creates difficulty in measuring biodiversity difference and change. The authors suggest that
well-sampled data can be used to generate a range of numerical indices reflecting species group characteristics/
functionality that can be viewed in combination to create a picture of Biodiversity Quality.
Examples of this approach demonstrate how to expand the currently accepted Convention on Biological
Diversity definition, based on the “variability” of genes, species and ecosystems, since the numerical
expression of the indices allows the probability of difference between biodiversity quality trends and values
over time, and between sites or taxonomic groups, to be assessed for statistical inference of difference
or similarity.