324 Proceedings Portland Society Natural History 



the Adirondacks and scattered areas along the higher Ap- 

 palachians. Much of this territory has sterile acid soils, a 

 distinct glacial topography and usually poor drainage. 

 The climax forest consists of sugar maple, beech, hemlock, 

 yellow birch, white pine, balsam fir and spruces and consti- 

 tutes the "spruce-northern hardwood" region of the lum- 

 bermen. The climatic climax is attained on the better sites, 

 but on much of the area coniferous forests occur, which rep- 

 resent physiographic climaces due to local edaphic or topo- 

 graphic factors. 



2. THE ALLEGHANIAN-TRANSITION ZONE. this ZOne OC~ 



cupies the western and southern portions of the Transition 

 region, an area with the lower rainfall-evaporation ratios. 

 The climax forest consists of sugar maple, beech, yellow 

 birch, hemlock, and white pine and constitutes the "northern 

 hardwood" region of the lumbermen. Physiographic cli- 

 maces are also frequent in this zone and are often wide- 

 spread, as seen for example in the white pine region of New 

 England and the jack pine region of Michigan and Wiscon- 

 sin. 



Due to the effect of local factors the vegetation in 

 many localities may not coincide with any of the above 

 groups. Coniferous species, for example, may be present 

 in bogs in an otherwise purely deciduous region ; and sim- 

 ilarly southern forms may occur locally in a northern re- 

 gion. These exceptions to the usual order of things are 

 interesting, however, only from the standpoint of the dis- 

 tribution of the individual species concerned, and they may 

 be neglected in a consideration of the vegetation of the re- 

 gion under observation. 



There are also instances where, within the limits of one 

 climatic formation, there occur typical areas of a more 

 northern climatic formation. Such a condition exists on 

 the upper slopes of the higher mountains, such as Katahdin, 

 the White Mountains, Adirondacks and some of the peaks 

 of the southern Appalachians, where a deciduous or transi- 



