472 



Dynamics of the Ecosystem 



TABLE 20 



Abundance of Breeding Animals on 1 Square Mile (3 sq km), Santa Rita 

 Range Reserve, Arizona (After Leopold, 1933) 



in abundance of the carnivores, such as the coyotes, hawks, or owls, 

 and of the herbivores, such as the quail or the mice, are striking; an 

 even greater contrast in numbers would have appeared if the census 

 had included the insects and other invertebrates. An example of the 

 pyramid of numbers on a small scale is furnished by a census of the 

 metazoans inhabiting the floor of a deciduous forest ( Fig. 13.3 ) . 

 In addition to the foregoing relations of biomass, size, and num- 



Number per kilogram 

 Fig. 13.3. Pyramid of numbers among the metazoans of the forest floor in a 

 deciduous forest near Evanston, Ilhnois. (Park, Allee, & Shelford, 1939, Copy- 

 right, Univ. of Chicago Press.) 



