CHAPTER III 



VEGETATIONAL ANALYSIS 

 QUANTITATIVE METHODS 



FIXING THE CONCEPT OF A COMMUNITY 

 The fallacy of doing detailed physiological studies with an un- 

 named plant is obvious. If the physiologist does not know the 

 species with which he is working, his conclusions will be limited 

 to the particular group of plants he is using in his experiments. 

 The studies of taxonomists, floristic geographers, and geneticists 

 represent an accumulation of information and data upon which 

 the physiologist can draw and which he can use to make general- 

 izations and comparisons. All this information is connoted by the 

 scientific name of the plant being studied. 



The ecologist, although working with communities, deals with 

 problems similar to those of the physiologist when he sets up the- 

 ories, attempts to find causes, to draw conclusions, or to formulate 

 laws. But the ecologist is faced with the necessity of determining 

 the make-up of the community with which he works before he 

 can proceed to an investigation of causes or to experimental con- 

 siderations. At present, most of the larger, regional, climatic vege- 

 tation types are so well known that their concepts are probably as 

 distinct to the ecologist as are those of most common species to 

 the taxonomist. For lesser communities, however, this is not true. 

 Furthermore, identification of such a community in terms of a 

 specific concept requires more than a superficial examination. Per- 

 haps an ecological classification of plant communities will never be 

 achieved with the same degree of perfection found in taxonomic 

 classification; perhaps such perfection is not necessary. It is neces- 

 sary, however, that there be means of characterizing a community 

 with sufficient accuracy to permit identification at any time, to 

 compare it with other similar communities, and to have an ade- 

 quate permanent record of its nature and occurrence. Undoubted- 

 ly, if such work is well done, it is justified on its own merits as a 

 phase of ecological investigation. 



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