THE WILDWOODS 



27 



At first it culls the forest and reduces the number of kinds 

 of trees, — tlie ehn, the ash, the basswood, etc., drop out, and 

 the forest is finally reduced to open stands of scrubby oak. 

 Where the moisture becomes scarcer still these scrub woods 

 become more dwarfed, and soon the forest ceases altogether. 

 Lack of moisture then reduces the number of species ; it 

 stunts and, if extreme, it prevents forest growth altogether. 



Fic. 14. Too IMucli W;itcr kills 

 Tinil)er killed by water backed up by state dam in Ailiroiidaeks. (After Fox) 



Thus, a lack of moisture acts like a poor, sandy soil, and 

 wherever these two combine the effect is all the greater. 

 Let us now see what too much moisture does. When 

 the lumbermen in our northern forests dam up a stream 

 to store water for driving purposes, they select some large 

 flat, where a pond of considerable extent is produced by 

 the dam. Li such a place large numbers of trees, which 



