DECIDUOUS FOREST COMMUNITIES 239 



americana, are also important dominants in this association. The 

 hemlock, Tsuga canadensis, the environmental requirements of 

 which are much the same as those of beech and maple, is often present 

 and appears like a dominant but is usually considered a relict of a 

 former time when the pine-hemlock coniferous forest is believed to 

 have extended farther south. Several other species of trees, includ- 

 ing several oaks, which are more important in other associations also 

 occur in the beech-maple forest. 



The beech-maple forest is a magnificent and extremely interesting 

 vegetation type and contains a very large number of species, not 

 only of trees but also of shrubs and herbs. No other forest can boast 

 of a more attractive succession of seasonal societies. The spring 

 flower societies are especially attractive but the autumnal societies, 

 composed mostly of composites, are fully as striking. 



The oak-chestnut-yellow poplar forest occupies a strip through the 

 middle of the deciduous forest formation extending from Connecticut 

 and eastern New York through southern Pennsylvania and eastern 

 Ohio to northern Alabama and Mississippi (Fig. 106). It occupies 

 the greater part of Kentucky and Tennessee and much of West 

 Virginia. Formerly the characteristic dominants w^re the- chestnut 

 oak {Quercns montana), the chestnut {Castanea dentata), the yellow 

 poplar {Liriodendron tidipifera), and, in some parts, the scarlet oak 

 (Q. coccinea) . In the early part of the present century nearly all of 

 the chestnut w^as killed by the chestnut bark disease so that this 

 species is no longer an important constituent of the forest. The 

 number of species of trees associated with the dominants in this 

 forest is greater than in any other in the United States and formerly 

 some of the most luxuriant deciduous forests in the world were found 

 in the Ohio Valley. 



The oak-hickory forest is found between the oak-chestnut-yellow 

 poplar forest and the prairie. It extends from south central Texas 

 through Oklahoma, INIissouri, southern Illinois, Indiana, western 

 Ohio, southern IMichigan and Wisconsin, and a rather narrow band 

 through south central Minnesota. This is also the type of forest 

 that extends into the prairie along streams. The principal dominants 

 are the red oak {Quercns rubra), black oak (Q. velidina), white oak 

 (Q. alba), bur oak (Q. macrocarya), shellbark hickory {Carya ovata), 

 mockernut (C alba), and, in the southern part, pecan (C. yecan). 

 However, there are several other species of oaks and hickories that 

 are nearly as important as those named. In the forested parts of 

 Oklahoma and Texas there are considerable areas that are occupied 



