A SUMMARY OF BOG THEORIES^ 



GEORGE B. RIGG 

 University of Washington, Seattle, Washington 



Various theories have been offered in explanation of the fact 

 that plants other than bog xerophytes are largely inhibited 

 from sphagnum bogs. In this paper the writer has arranged 

 systematically the various theories on this question that have 

 come to his attention and has cited the literature bearing on 

 each so far as he has had access to it. 



DEFINITION 



By the term "sphagnum bog" the writer means that stage in 

 the physiographic succession of an area during which its surface 

 is entirely devoid of ordinary "hard" soil, and is composed 

 completely of Uving sphagnum moss under which is fibrous 

 brown peat composed mainly or entirely of partially decayed 

 sphagnum. 



This is the sense in which the writer has used the terms "bog" 

 (41, p. 314) and "sphagnum bog" (42, p. 167) with reference 

 to the Puget Sound region and the coastal region of Alaska. It 

 corresponds closely to the following terms of other writers, 

 "sphagnum moor," Sitenskj^ (51) and Warming (60); "sphagne- 

 tum" ("raised bog association," "hochmoor"), Ganong (25, p. 

 442); "hochmoor," Friih und Schroter (23, p. 129); "Cassan- 

 dra zone," Weld (62, p. 43); "sphagnum-heath zone," Tran- 

 seau (56, p. 370); "zone of bog shrubs," Burns (1, p. 106); 

 "Bog-meadow association" and "bog heath association," Dach- 

 nowski (22, pp. 31-34 and 20, pp. 238 and 244). 



A tabulation of the distinguishing characters of the ''flach- 

 moor"and of the "hochmoor" has been made by Friih und Schroe- 



^ Paper read at a meeting of the Ecological Society of America at San Diego, 

 California, August 10, 1916. 



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