Science would first like indicators OF biodiversity.
Biodiversity is life.
All the definitions used are simply subdivisions along the virtually endless gradients of space, time and taxa. However, some points on these gradients appear both necessary and pragmatic to biodiversity evaluation for sustainable management. The pragmatic and necessary point on the spatial gradient. However these have been found to be unhelpful for discriminating, characterizing or managing the attributes of system biodiversity. However, as some correspondants have shown, we can use a frame of reference as the indicators.