THE CLIMAX FOREST AND ITS PREDECESSOR 203 



country. The plants and animals of the forest floor are there- 

 fore shade-loving and moisture-loving forms. 



The maple-beech forest is the last in the succession because 

 in the dense shade under these trees few seedlings other than 

 beech and maple can survive; the young of the other trees 

 demand more light. This is probably only one of several factors 

 important in the "elimination of other seedlings. As the pine 

 forest grows old and dense, black oak seedlings appear, and these 

 trees gradually overtop the pines, the latter dying in the struggle 



FIGS. 245-247: Fig. 245. Leaf and flower of tulip tree, Lirodendron Tulipifera; 

 Fig. 246. Leaf and nut of white walnut, Juglans cincrea; Fig. 247. Leaf and nut. 

 of black walnut, /. nigra. 



for existence. So in the black oak forest seedlings of red and 

 white oak appear, and when mature they shut out the black oak, 

 but the beech-maple forest has only beech and maple seedlings 

 together with a few other trees that can stand the same con- 

 ditions. There will be an occasional tulip tree (Fig. 245), black 

 and white walnuts (Figs. 246, 247), black cherry (Fig. 248), 

 hackberry (Fig. 249), with some elms (Fig. 250), and sycamore 

 (Fig. 251) in the lower portions. 



The tulip tree (Fig. 245) is recognized by its large leaf, shaped 

 something like a maple leaf with the tip cut square off. The 



