According to the concept of species-area relationship

German naturalist and geographer Alexander von Humboldt, after his studies in south american jungles, observed that within a specific region species richness is increased with increasing area, but only up to a limit. Exactly the relation between species richness and area for a wide variety of taxa (angiosperm plants, birds, bats, freshwater fishes) was found to be a rectangular hyperbola. On a log scale, the relationship between species and area is a straight line described by the equation: log S = log C + Z log A.