{From the BULLETIN OF THE TORREY BOTANICAL CLUB 47: 21-33. 31 Ja 1920 | 
Some applications of the quadrat method 
HENRY ALLAN GLEASON 
By the quadrat method in ecological phytogeography is meant 
the intensive study of the vegetation or environment of a limited 
and definitely circumscribed area, known as a quadrat, in order 
to gain a comprehensive knowledge of the vegetation as a whole. 
The development of the method is the direct outgrowth of a need 
which has been felt by every ecologist who has seriously attempted 
the study of vegetational units. While its use is of great value 
and leads frequently to generalizations which would otherwise be 
difficult or impossible, it is not complete in itself, and ecologists 
are unable to rely upon it alone as a means toward successful 
field work. Indeed, its use to the exclusion of all other methods 
has never been suggested. It does constitute, however, the only 
practicable means for the quantitative study of the association, 
and as such it forms an important adjunct to photography and 
verbal description, which were previously the only feasible means 
of presenting the structure of vegetation. It also plays an im- 
portant part in the study of associational dynamics, as migration 
and succession, and environometry. 
It is exceedingly difficult and in many cases impossible for a 
reader to form a clear mental picture of an association from a 
written description, as may be demonstrated by a perusal of any 
discussion of an otherwise unfamiliar type of vegetation. The 
value of a verbal description is always greatly enhanced by photog- 
raphy. There are certain physical limitations to the value of a 
general photograph, caused by the difficulties of field photography 
and the necessity of reducing the print to the usual compass of a 
Page, so that a general view of an association seldom gives a 
sufficiently clear idea of the vegetation, since the component 
species are distinguishable only in the immediate foreground, if at 
all. A detailed photograph of a small part of the association, on 
the other hand, is frequently made with difficulty and it is often 
impossible to choose for illustration an isolated portion which is 
