Some systems, however, show a poor fit between system size and species richness.
It is generally a much more useful value than species richness.
In these cases, therefore, the negative effects are not only at the population level but also species richness of communities.
There has been much discussion about the relationship between productivity and species richness.
This has resulted in the high species richness observed within the area.
Species richness peaks at around 40 latitude, both north and south.
The theory was developed to explain species richness of actual islands.
Species richness - the least sophisticated of the indices available.
The species richness of plants in fields decreased by eight per cent between 1978 and 2008.
Knowing species richness and abundance in a given area has been an important part of ecology since its creation.