ORGANIZATION OF LAND COMMUNITIES 61 



The forest margin, the edge where the aspen 

 forest meets the prairie, forms a separate com- 

 munity. There the aspens are still the most 

 important plants but their associated plants differ 

 from those of the mature woodland and the in- 

 fluential animals are also different. Along the 

 forest margin the most important animal is the 

 snowshoe rabbit. Some idea of the extent of its 

 influence may be seen from the fact that in a 

 square of 25 meters 39 per cent of the aspens had 

 been ringed and killed by rabbits and all of the 

 associated hazelnut, rose and chokeberry bushes 

 were dead as a result of rabbit attacks. Obviously 

 the rabbits are a strong influence in retarding the 

 invasion into the prairie of the aspens and their 

 associated shrubs. 



The rabbit breeds in the forest margin. Many 

 are killed, especially in winter by coyotes, owls, 

 hawks and weasels as well as by men, both red 

 and white. Coyotes and weasels and skunks are 

 more characteristic in many ways of the open 

 prairie but they breed in the forest margin. The 

 birds also include characteristic species that feed 

 in the open. The invertebrate life is less here 

 than in the prairie or in the woodland proper but 

 in the autumn there is a great migration partic- 

 ularly of insects from the open country to the 

 protection of the forest-margin bushes. The 



