580 PLANT GROWTH AND PLANT COMMUNITIES 



TABLE V 



A Simplified Life-Form System." W = erect woody plants; L = climbing or 

 decumbent woody plants; E = epiphytes and crusts; H = herbs; M = bryoids. 



* From Dansereau, 1951, 1958b. 



Stance, general shape and texture. My 1951 and 1958b system allows 

 such a grading, which is appHed in Table VI and VII and which shows 

 very sharp differences between the communities. For instance, the 

 graminoids are most prominent in the Lythretum, the Spiraeetum, the 

 Solidaginetum, the Poaetum; the broadleaved are overwhelmingly 

 more important in the Aceretum saccharophori laurentianum and in the 

 Aceretum saccharophori tsugosum than elsewhere; very small leaves, 

 needle or subulate, are quite absent from five communities, whereas 

 they are 10 per cent or more in four others. These differences are much 

 more pronounced if a coverage coefficient is used (column B in Table 

 VI). For instance, the spatial importance of the needle type in the 

 Thujetmn association rises from 7.15 per cent to 55.5 per cent. 



Leaf texture likewise shows a very uneven distribution. The 

 meadow ( Poaetum pratensis ) has an almost all-membranous leaf type, 

 whereas six communities have 10 per cent or more hard-leaf type. The 

 filmy-leaf type is very poorly represented— in only three communities. 

 And here again the use of a coverage coefficient strongly emphasizes 

 the differences: the succulent or fungoid type, although represented 

 by many species, has little spatial value; the sclerophyll type is ex- 

 tremely important in the cedar wood and the hardwood-hemlock forest. 



