An Ecological Study of Buckeye Lake. 7 



Other authors extend the term formation to cover a much larger 

 concept, whose Hmitation is based on the water available to 

 plants and therefore recognize Xerophytic, Mesophytic and Hy- 

 drophytic formations. 



The term association is also variously interpreted ; but be- 

 ing employed in a more restricted sense than formation there is. 

 greater unanimity of opinion. - ^v, ,<i»8i;. 



In this paper an association stands for a unit of vegetation 

 exhibiting a definite growth form, which is characteristic of a 

 certain habitat. For example : — the upland meadows in the 

 vicinity of Buckeye Lake are occupied by grass associations, 

 the bog-meadow of Cranberry Island is occupied by a Cranberry- 

 Sphagnum association. The dominant species in each case giving 

 character to the association. 



The various associations include ecologically related com- 

 munities of species having definite floristic composition. These 

 are grouped in societies to which the principal ones give name 

 and character. In certain areas in the bog-meadow Dulichium 

 arundinaceum occurs with the Oxycoccus and Sphagnum in 

 such abundance as to give a definite character to those areas 

 and forming an Oxycoccus-Sphagnum-Dulichium society. Again 

 altho Sphagnum cymbifolium is the most abundant and widely 

 distributed species of Sphagnum in the bog, there are areas in 

 which Sphagnum acuti folium var versicolor occurs to the almost 

 complete exclusion of S. cymbifolium. As these two species 

 differ greatly in appearance the contrast between the two 

 Sphagnum societies is striking. 



A marsh offers another illustration of well defined associa- 

 tions, distinguished by plants of most characteristic growth- 

 form e. g. : — erect plants with slender culm-like stems and long 

 relatively narrow leaves, with the roots, rhizomes and lower 

 portion of the erect stem only, submerged in relatively quiet, 

 shallow water along the margins of lakes, bays and gulfs and 

 sluggish streams. The dominant plant may be a Tyi)ha, a grass 

 or a sedge. The particular marsh is then a Typha, grass or a 

 sedge association according to the plant which lends it character. 



