HISTORICAL DEVELOPMENT OF THE CONCEPT 7 



Dahl (1903-1908). In three successive editions of his guide for 

 collecting and preserving animals (1903, 1904, 1908), Dahl adopted 

 Mobius's term, but clearly not in the sense of a biotic community, at 

 least in most instances. This is further -shown by the fact that he 

 speaks only of zootopes or animal habitats, and in addition states 

 that the biocenose is for the zoologist what the plant conununity is 

 for the botanist. Three types of biocenose were recognized, namely, 

 phytobiocenose, zoobiocenose, and allobiocenose, composed respectively 

 of the animals to be found on a particular plant or its parts, on an 

 animal, or on inorganic or decaying organic bodies. The subdivisions 

 of the first two and especially the phytobiocenose correspond to all 

 the organs and parts of the host and obviously represent only the most 

 minute animal assemblages. Among the allobiocenoscs were included 

 autonomous communities, but usually without indication of their biotic 

 nature. 



Clements (1905-1918). In "Research Methods in Ecology" 

 (1905:16), it was stated that plant and animal communities fre- 

 quently coincide. Since animals were regarded as typically motile, 

 their dependence upon the habitat was considered to be less evident. 

 Vegetation as the source of protection and food plays a more obvious 

 if not a more important part. It was stated that the animal ecology 

 of a terrestrial region could be properly investigated only after the 

 habitats and the plant communities have been organized as the basis 

 for studying development and structure. 



In a study of the life history of the lodgepole pine burn forest 

 (1910), animals were found to play a controlling part in succession. 

 The frequent regeneration in burns, by contrast with the absence of 

 seedlings elsewhere, led to the conclusion that a major effect of fire 

 was to destroy or drive out the seed-eating animals, and permit the 

 establishment of the pure stand of pine (consocies) as a characteristic 

 subclimax. 



In a monographic discussion of succession (1916), the biotic forma- 

 tion was regarded as an organic unit comprising all the species of 

 plants and animals at home in a particular habitat. Plants w^re con- 

 sidered to exert the dominant influence, although it was recognized 

 that this role might sometimes be taken by the animals. The biotic 

 community is fundamentally controlled by the habitat and exhibits 

 both development and structure. In its development the biome reacts 

 upon the habitat and thus produces a succession. In discussing the 

 scope and significance of paleo-ecology (1918), it was stated that 

 recognition of animals as a part of the community promised to open 

 a new outlook in svnthetic ecology. 



Adams (1906-1915), Ruthven \l911). In sketching the plan for 

 a survey of Porcupine Mountains and Isle Roj^ale, Michigan (1906), 

 Adams based this upon the relations of the biota to environment, 

 adopting Stcjneger's definition of the biota as "the total of animal 

 or plant life of a region." While there was no definite recognition 

 of the biotic community, the cmjihasis upon the habitat and upon 

 processes in terms of succession, and the use of plant communities 

 as a groundwork, mark the treatment as distinctly synthetic. The 



