The relation between species richness and area for a wide variety of taxa turns out to be a rectangular hyperbola. Give a brief explanation. 

Species richness in any area depends on various factors. Some of them are as follows: 
(a) Balance between immigration and extinction 
(b) Rate and magnitude of disturbance in small area Vs large area 
(c) Predator prey dynamics 
(d) Clustering of individuals of the same species because of dispersal limitations. 
When the area increases up to a certain extent, number of species Increases; as shown by the graph. This can happen because of reduced rate of disturbance and because of favourable predator prey dynamics. Once the area increases beyond the threshold level, there Is no growth in number of species. This can happen because of dispersal limitations.