I'he Ohio 'Naturalist, 



PUBLISHED BY 



The Biological Club of the Ohio State Uni'versity. 

 Volume XI. NOVEMBER, 1910. No. 1. 



TABLE OF CONTENTS. 



Dachnowski— A Cedar Bog in Centnil Ohio 193 



Detmers— A Klori.stic Survey of Orchard Ishind 200 



Nichols — An Open Valley near Harrisburg, Ohio 210 



Hood— Some Economic Monocotyls of Ohio 214 



Dickey— Meetiiiii- of the Biological Club v 216 



A CEDAR BOG IN CENTRAL OHIO.* 



Alfred Dachnowski. 



Ohio is one of the states of a central region in which the 

 dominant vegetation is the deciduous forest. Our forests are a 

 type of plant formation, with a distinct physiognomy and growth- 

 form, both of which are an expression of certain definite conditions 

 of life. Deciduous forests characterize all regions in which there 

 is an abundant rainfall well distributed through the growing 

 season, a relatively high percentage of atmospheric humidity, and 

 a relatively high annual sum total of temperature exposure. 

 Before settlement by immigrants from Europe, Ohio was almost 

 completely covered by dense forests. Here and there, in ravines, 

 in depressions between morainal hills, on the highlands of water- 

 sheds, were restricted areas of bog and marshland, sometimes 

 many thousands of acres in extent, "filled in" ponds and lakes, 

 another type of plant fonnations, of which the component species 

 now tenanting such areas, and their relative proportion seemed 

 more like an allusion to the distant north. Indeed they are 

 relicts of a boreal vegetation which skirted the border of a great 

 ice sheet covering almost all of Ohio. For reasons which will be 

 stated in another paper these isolated areas of northern plant 

 societies maintained themselves, and remained behind during the 

 great migration of plants, while most of the plant societies adjusted 

 to a northern climate, retreated northward with the glaciers as the 

 winter conditions of the glacial period slowly changed to the 

 present climate. 



*By permission of the State Geologist. Contribution from the Botanical 

 Laboratories of Ohio State University, No. 57. 



193 



