major functional attributes are: • continuity of nutrient cycles or biogeochemical cycles (N , C, H O, P, S cycles) • soil formation, conditioning or maintenance of soil health (fertility) by certain limit. The relationship between species richness and area for a wide variety of taxa (angiosperm plants, birds, bats, freshwater fishes) turned out to be the rectangular hyperbola. On a logarithmic scale, the relationship is a straight line described by the equation. log S = log C + Z log A where S = Species richness A = Area Z = Slope of the line (regression coefficient) C = Y-intercept S=CA z Species richness log-log scale log S = log C + Z log A (A) Area (S) (S) Fig.
. Species - Area relationship on log scale Regression coefficient Z generally has a value of . - . regardless of taxonomic group or region.
However, in case of the species – area relationship in very large areas like entire continents, the slope of the line appears to be much steeper (Z-value in the range of . - . ). For example, in case of the fruit eating (frugivorous) birds and mammals in the tropical forests of different continents, the slope is found to be a steeper line of .