NEET Botany Biodiversity and Conservation Questions Solved


The given graph shows the species-area relationship. Answer the following questions as directed.

(a) Name the naturalist who studied the kind of relationship shown in the graph. Write the observations made by him. 

(b) Write the situations as discovered by the ecologists when the value of 'Z' (slope of the line) lies between (i) 0.1 and 0.2 (ii) 0.6 and 1.2. What does 'Z' stand for?

(c) When would the slope of the line 'b' become steeper?                                               


(a)   (i) Alexander Von Humboldt has observed that within a region, speices richness increased with increased explored area, but only upto a limit. 

     (ii) The relationship between species richness and area for a number of taxa like angiospermic plants, freshwater fishes and birds is found to be a rectangular hyperbola.

   (iii) On a logarithmic scale, the relationship is a straight line described by the equation.     

[ Where 

 S= Species Richness 

Z= Slope of the line (regression coefficient)

A= Area and C= Y-intercept.

  log S=log C + Z logA

(b) Ecologists have discovered that the  value of Z lies in the range between 0.1 and 0.2 regardless of the taxonomic group or the region whether it is the plants in Britain, birds in California or molluses in New York State, the slopes of the regression line are amazingly similar. 

Z= Slope of the line (regression coefficient)

(c) If species area relationship is very large like the entire continents then the slope of the line is much steeper (Z values in the range of 0. - 1.2). E.g., for frugivores (fruit-eating) birds and mammals in the trophical forests of different continents, the slope is found to be 1.15.


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