The variety and variability among living organisms from all sources including, inter alia , terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems. Diversity indices are measures of richness (the number of species in a system); and to some extent, evenness (variances of species' local abundance). They are therefore indifferent to species substitutions which may, however, reflect ecosystem stresses (such as those due to high fishing intensity). (FAO, 1997) .
ncludes genetic diversity (within species), species diversity (within ecosystems) and ecosystem diversity . Diversity indices measure the richness (the number and relative numeric abundance) of species in a system, and the connections between them but are indifferent to species substitution, which may, however, reflect ecosystem stress (such as those due to high fishing intensity). See: Biodiversity