What is the significance of the slope of regression in a species-area relationship?

Significance of the slope of regression in a species-area relationship:

• It gives an estimate of species richness of area.
• As it's values can not deviate very much, it tells that the species richness vary from one place to another but cannot be zero or very high. This means that there will not be any case when no species will be present in an area.
• It is independent of taxanomical category or type of area studied.