CHAPTER X 

 METHODS OF STUDYING VEGETATION 



215. The study of vegetation. It is desirable to study the 

 effect of physical factors upon vegetation with the same care 

 and thoroughness that are used in the case of the plant. As is 

 shown more clearly later, vegetation responds to the habitat 

 by means of changes and structures, which correspond in a general 

 way to the functions and structures of the ifidividual plant. It 

 accordingly exhibits both adjustment and adaptation. In other 

 words, it is possible to trace the development of vegetation and 

 to study and record its structures. In order that these primary 

 tasks may be carried out wdth accuracy and thoroughness, it has 

 been necessary to invent methods which yield definite and detailed 

 results. The latter are just as necessary for vegetation as for the 

 plant. In fact the careful study of the habitat and plant loses 

 much of its value if it is not also extended to the vegetation. 



Methods suited to the study of vegetation must make it possible 

 to discover and follow the smallest changes and to recognize the 

 innumerable details of structure. In addition they must be of 

 such a nature that they furnish a complete and detailed record 

 of all the changes and structures found. The quadrat method, 

 with its modifications, meets all these requirements, and in con- 

 nection with . maps, photographs, and formation herbaria forms 

 a complete system for the exact study of vegetation.^ 



216. The quadrat. As the name indicates, the quadrat is a 

 square area of varying size marked off in the formation, i.e., one 

 of the many units that make up vegetation. In its simplest form, 

 it is used to count the individuals of each species, and to determine 

 the relative abundance and imoortance of the species of a forma- 



' Research Methods, pp. 160-198. 



202 



