112 



INTRODUCTION TO BOTANY 



was to devise ready means of getting rid of the trees which 

 covered the land (fig. 94). A large part of the territory ex- 

 tending east and southeast from the Great Plains region to 

 the Atlantic and the Gulf of Mexico was forest-covered. 



Now that these im- 

 mense primeval forests 

 have been destroyed, 

 never to be renewed 

 in their original luxu- 

 riance, we are coming 

 to realize that in re- 

 moving them the early 

 settlers put an end to 

 an almost unlimited 

 source of income, and 

 greatly injured the soil 

 and climate of large 

 areas. Some of the land 

 had to be cleared in 

 order to make tillable 

 fields to grow bread- 

 stuffs for the earliest 

 settlers, but it is unfor- 

 tunate that the clear- 

 ing process was so 

 well-nigh universal. 



105. Pure and mixed 

 forests. Some forests 

 are composed almost 

 entirely of a single kind of tree, like the long-leaf pine 

 growth of figure 229. A few of the hard-wood trees, as the 

 birches, oaks, and maples, are not infrequently found growing 

 nearly unmixed with other trees. More frequently, however, 

 two or more kinds of conifers grow intermixed in the same 

 forest, and the hard-wood trees are still more likely to occur 

 with several kinds associated. Thus we find in the same 



FIG. 94. A "deadening" ; trees killed by gir- 

 dling near the base to clear the land for corn 



Photograph by United States Forest Service 



