Who observed that within a region, species richness with increasing explored area but only up to a limit? a. Paul Ehrlich b. David Tilman c. Alexander von Humboldt d. Edward Wilson
Option C. During his pioneering and extensive explorations in the wilderness of South American jungles, the great German naturalist and geographer Alexander von Humboldt observed that within a regional species richness increased with the increasing explored area, but only up to a limit. In fact, the relationship between species richness and area for a wide variety of taxa (angiosperm plants, birds, bats, freshwater fishes) turns out to be a 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.