Part 4 - Community Dynamics 



CHAPTER IX 



PLANT SUCCESSION 



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HISTORICAL BACKGROUND 



When a cultivated field is permitted to lie fallow, it produces 

 a crop of annual weeds the first year, numerous perennials the sec- 

 ond year, and a community of perennials thereafter. In forest 

 areas, the perennial herbs are soon superseded by woody plants, 

 which become dominant. After any disturbance of natural vege- 

 tation—such as cultivation, lumbering, or fire— a similar sequence 

 of communities occurs with several changes in the dominant vege- 

 tation through the years. 



Such relatively rapid vegetational changes are familiar to most 

 people today and must have been observed hundreds of years ago. 

 It was not until the seventeenth century, however, that any syste- 

 matic study of such changes was made, and those studies dealt 

 primarily with the development of peat bogs. Bog studies were 

 continued in the eighteenth century, and, in addition, some at- 

 tempt was made to apply the principles to burned and disturbed 

 upland areas. It was then that the term, succession, was first ap- 

 plied to the vegetational changes involved. During the nineteenth 

 century, succession was considered rather frequently but invari- 

 ably as incidental to other problems. Several writers hinted at the 

 importance of succession in all habitats, but it was not until 1885 

 that a regional study of vegetation in Finland was made in which 

 succession was recognized as fundamental to all community de- 

 velopment. 



Between 1890 and 1905, the modern concepts of succession 

 were clarified through the efforts of several writers. Two, whose 

 influence has been as great as any, were Americans. In the first 

 comprehensive application of successional principles in the United 



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