An Ecological Study of Buckeye Lake. 37 



tending is being invaded by oaks changing the bog to a meso- 

 phytic forest. ^^ 



The general character of the vegetation of the island is 

 that of a bog meadow surrounded by a border of trees, shrubs 

 and taller herbs, and this by a more or less complete marginal 

 marsh zone. (Fig. 13) The surface of the meadow is inter- 

 rupted by the presence of thickets of trees and shrubs, by Typha 

 clumps and by open pools. The shrub border is also much in- 

 terrupted by enclosed pools, marginal lagoons and coves. 



A critical study of the flora disclosed the presence of the 

 following associations. 



I. Floating aquatics association. 

 IL Fixed aquatics with submerged leaves. 



III. Semi-aquatic plants growing characteristically in 



shallow water from 5^ feet to emergence on mud 

 flats at low water. 



IV. Marsh association. 



V. Bog-meadow association. 



VI. Heath or low shrub association. 



VII. Bog-thicket or high shrub association. 



VIII. Bog-forest association. 



I. Free floating macroscopic plants. 



Spermatophyta wdiolly on the surface as the Lemnaceae, 

 floating forms as Utricularia minor, Pteriodphyta as the Salvin- 

 iaceae; Bryophyta as Riccia and Ricciacarpus together with Al- 

 gae, the filamentous forms as Cladophora sp. and Spirogyra com- 

 prise the formation. 



The association occupies the shallow water at the margin 

 of the island and comprises the principal, often the entire vegeta- 

 tion of the pools both marginal and enclosed, whether these pools 

 are in the shrub zone or in the bog-meadow. 



These plants are associated in various societies whose dif- 

 ferences expressed by the dominant species seem to be due to 

 dififerences in the depth of the water and the light exposure. 



