Quadrat Method in Forestry Investigations 13 



of noting relative vegetative progression than of establishing 

 definite square units of vegetation. While the square t unit (the 

 quadrat if that cognomen is desired) is sometimes used, experi- 

 ence has taught the forester that the square unit of definite 

 dimensions is not generally adapted to conditions under which 

 he is working due to superficial obstacles as well as for other 

 reasons. The shape and size of the vegetative plot may be square, 

 rectangular or even irregular, this being almost wholly deter- 

 mined by the nature of the investigation, character of the vege- 

 tation, the surface, whether regular or irregular, and the detail 

 necessary in obtaining results. As a concrete example, a per- 

 manent woodlot sample plot may consist of several acres of land, 

 the topographic features and striking vegetative characters of 

 which may be recorded in a more or less general way. Within 

 the major plot detailed sample sub-plots of varying size, from 

 two or three feet or a meter square (quadrat) to a rectangular or 

 irregular area many times the size of the meter quadrat, may be 

 established in various places. The main plot may be blocked 

 off into convenient segments for general study and the sub-plots 

 within the former similarly segregated to suit the detailed con- 

 ditions of the investigations. 



Kinds and Use of Different Plots. 



Use is commonly made of what ecologists generally recog- 

 nize as ( 1 ) the chart plot, which, as the reader will recall, derives 

 its name from the fact that the species making up the vegetative 

 cover within the boundary of the square or rectangle are located 

 in situ; (2) the list quadrat in which the abundance and com- 

 position of the vegetative cover within the limits of the plot are 

 recorded or listed usually regardless of location and relationship ; 

 (3) the depopulated plot in which the vegetation is removed in 

 varying degrees to total denudation. "Cleared," "thinned," anu 

 other names are given to sample plots according to the method 

 of removal used, but these terms are embodied in the designation 

 of "depopulated" plots. 



The forester makes use of the three kinds of plots above 

 mentioned in varying applied ways ; but since the types of vegeta- 

 tion and scope of investigations are greatly varied, having to do 

 with herbaceous as well as with shrubby and arborescent vegeta- 

 tion, his methods are probably more specialized, intensive as well 

 as extensive, than are those of the ecologist interested primarily 

 in ascertaining the relative rank of the plants in making up his 

 species or generic list of gregariyas, sub-gregarious and other 



