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

Explanation

slope of refression or refression coefficient of species area relationship indicates that species richness decreases with the decrease in area. Ecologists have found that refressic coefficient is 0.1-0.2 regardless of the taxonomic group or the region, e.g., plants in Britain, birds in California or molluscs in New York state. However, if very large areas like entire continents are analysed, the regressin coefficient is much steep with value of 0.6-1.2 it is 1.1 for frugivorous birds and mammals in tropical forests.