THE SUCCESSIONS OF VEGETATION IN OHIO LAKES 



AND PEAT DEPOSITS 1 



A Preliminary Report 



ALFRED DACHNOWSKl 



Ohio Stale University, Columbus, Ohio 



The report here outlined was presented at the Minneapolis 

 meeting of the American Association for the Advancement of 

 Science (1910). The survey of the vegetation was undertaken 

 for the Geological Survey of Ohio during the past two years. As 

 a result of investigations carried on in the laboratory certain 

 correlations have been determined between the different types 

 of vegetation and the available water content of the soil occupied 

 by each type. Other factors enter into the correlation but the 

 data in hand permit the tentative generalization that the relation 

 between the available water content and the respective quantity 

 required by plants is the chief limiting factor. 



The present distribution of the types of vegetation frequenting 

 lakes and peat areas renders necessary the recognition of the 

 geologic and physiographic features which originally determined 

 the sources of the Ohio flora. A detailed account of the geology, 

 soil, and topography of the state is given in a bulletin soon to be 

 issued dealing with the peat deposits of Ohio. No attempt will be 

 made to meet that want in this short paper. Ohio may be divided 

 into four physiographic regions, which in their climatic conditions 

 follow closely the divisions given by the U. S. Weather Service. 

 They have been named as follows: (1) The Lake region; (2) the 

 Western Morainic Plain or Calcareous region; (3) the Scioto 

 Valley region; (4) the Appalachian region. These physio- 

 graphic regions have a special interest and significance both as 



Contribution from the Botanical Laboratory, No. 65. 



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