508 



ECOLOGICAL CLASSIFICATION OF PLANTS 



Mesophytes, in contrast to Hydrophytes, are exposed much 

 more to the drying effect of the air and consequently are better 

 protected against transpiration. They need better root systems 

 for absorption and anchorage and also have better developed 

 conductive and mechanical tissues. There are many types of 

 mesophytic societies. 



Meadows and prairies are mesophytic societies in which trees 

 are absent, and the dominant plants are, therefore, grasses and 

 other herbaceous plants {Fig. 458). The most important of 



Fig. 458. — A prairie, a mesophytic society in which trees are absent. 



the woody mesophytic societies are the deciduous forests com- 

 posed of Maples, Beeches, Oaks, Tulips, Elms, Walnuts, and 

 other valuable trees {Fig. 4.59). In such forests grow also char- 

 acteristic societies of herbaceous planets. The thicket, composed 

 of small woody plants, such as Willows, Birches, Alders, Hazel 

 bushes, etc., is another woody mesophytic society. The most 

 remarkable of the mesophytic societies are the rainy tropical 

 forests, where, due to a heavy rainfall and great heat, vegeta- 

 tion reaches its climax, and gigantic jungles are developed, com- 

 posed of trees of various heights, shrubs of all sizes, tall and 

 low herbs, all bound together in a great tangle by vines and 

 covered by numerous epiphytes. 



