Nov., 1910.] A Cedar Bog in Central Ohio. 195 



of arborescent plants, bog relicts, weeds, and invading plants has 

 established itself. But even under such conditions an order of 

 invasion and succession is to a certain extent characteristic in the 

 movement of plants, and depends largely upon the extent to which 

 the plants are especially enabled to cope functionally with the 

 changing conditions and hold their ground. The time and chance 

 factors, i. e., the opportunity for occupancy of the area, the 

 relative amount of filling, and the degree of decomposition of peat 

 which has occurred in the basin, are of equal importance in com- 

 petition and maintenance. In all cases and at all times during 

 the phases of the development of a plant formation the invasion, 

 zonation, and succession of plant societies is intimately bound up 

 with differences in available soil water content, and available food 

 constituents which go concomitant with the degree of the 

 decomposition of peat soils. 



The most interesting of the many different kinds of bogs in 

 Ohio is a Cedar bog near Urbana in Champaign County about 

 forty miles west of Columbus. In a few places the character of 

 the county is hilly, and in the depressions occur peat deposits. As 

 a whole, however, the surface of the county is level and made up 

 of plains. The general fomi is that of a broad shallow trough, 

 lying north and south. Mad-River runs through the middle of 

 it, and drains the main body of the territory. 



On the east side of Mad River, in the southeastern part of 

 Mad River Township, and extending largely over into Urbana 

 Township (T5R11) in sections 31 and 32 is a tract of land known 

 as the Dallas Cedar swamp. It is about six miles south of Urbana, 

 and easily reached by means of the Ohio Electric Railway. The 

 Cedar Swamp is a part of an area of cleared bog which comprises to- 

 day about GOO acres. There was once an extensive deposit covering 

 approximately 7,000 acres. On a small portion of land owned by M. 

 and G. L. Dallas occur as described below groves of arbor vitae 

 (Thuja occidentalis) in a good state of preservation. The groves 

 occupy a habitat near which the soil water is derived from cold 

 springs along the poorly drained river valley. A considerable 

 number of soundings were made which disclosed for the first two 

 feet a blackish brown compact, well decomposed, non-fibrous 

 peat. iVt the third foot level the peat appeared dark brown, some- 

 what fibrous, with a considerable admixture of marl below. A 

 number of well preserved logs and branches were encountered. 

 At four feet the peat appeared brown and compact but fibrous in 

 texture with fragments of rhizomes and roots. At the five feet 

 level the sounding instrument encountered a coarse gravel with 

 stones showing glacial striations. This rested on beds of quicksand 

 and morainal till. The bog harbors a unique dependent flora which 

 long throve here unmolested and was once a favorable resort for 

 botanists. Now the cedars and the accompanying undergrowth 



