METHODS OF STUDYING VEGETATION 



203 



tion. In doing this, one discovers many points commonly over- 

 looked, and gains a fair idea of the minute structure of a bit of 

 vegetation. The quadrat is also used to follow the changing 

 aspects of a formation during the growing period and to show the 

 exact differences between diverse areas of it. In the chart quadrat 

 the position of each plant is noted and recorded upon the chart, 

 which thus becomes an indispensable record of structure, and a 

 starting-point for making out future changes. Permanent and 



Fig. 72. A quadrat with charting tape. 



denuded quadrats are modifications by which the exact study of 

 an area is extended over a term of years. 



While a quadrat is but a small bit of a formation, it shows 

 the exact structure of this bit. It is impossible to study the entire 

 area with the same thoroughness, but a number of cjuadrats 

 located with care in those places which appear different at a glance 

 will reveal the entire range of structure. The quadrat, like 

 any other method, must be tised with (liscriniiiiation, aiul not 

 located at random. 



217. Kinds of quadrats. The unit size of the quadrat is a 

 meter and this is the size of the quadrat commonly used. For 



