32 BOTANICAL GAZETTE Ijanuary 



Oak forest 



* 



Quercus rubra L. furnishes an unimportant and rare type. 

 Stands are seen near Walloon Lake, and on the Algonquin bluff 

 north of Harbor Springs, which extend inland in places for some 

 distance. This tree occupies the same sort of habitat as the pine, 

 and probably succeeds the latter in certain areas. Oak also covers 

 Harbor Point, a low Post-Nipissing area. The discontinuous dis- 

 tribution shown suggests relatively recent seeding at Walloon Lake. 

 Along the bluff north of Harbor Springs oak succeeds pine, when 

 trees of the former are near and the pines are far enough apart 

 (or have been cut or burned off) . This occurs especially where the 

 slope is not steep. Invasion of the adjacent upland by oak has 

 occurred in one place (5). Quercus velutina is absent from this 

 region (13). 



Hemlock forest 



The few stands of Tsuga canadensis Carr. left are confined to 

 areas similar to those bearing pine, but of less xerophytic nature. 

 It appears that any area bearing hemlock in this region is eco- 

 logically prepared for the climax forest, for, aside from the fact that 

 hemlock is more or less common in the climax forest itself, and that 

 hemlock stands normally bear some deciduous trees, the under- 

 growth and seedlings of an open hemlock forest are usually decidu- 

 ous, and where the trees are cut off the young growth is largely 

 maple and beech. The periodic reproduction of conifers may have 

 a disadvantageous influence on their persistence. On the low 

 hills bordering Walloon Lake a nearly pure stand is common, run- 

 ning from an average of 20 cm. diameter to a maximum of 80 cm. 

 In such a primary society few herbs or seedlings are scattered over 

 the brown needle layer. The characteristic plants are Taxus 

 canadensis Marsh, Lycopodium hicidulum Michx., L. clavatum L., 

 Clintonia borealis Raf., and Mitchella repens L. Where cut off, 

 the sapling flora is almost exclusively deciduous, being about 60 per 

 cent Acer saccharum Marsh, mixed with Fagiis grandifolia Ehr., 

 Acer pennsylvanicum L., and A. spicatum Lam. 



Beyond Menonaqua the pines adjoin a hemlock beech society, 

 which very likely will succeed them. This represents the richest 



