l64 . THE FORMATION 



Kinds of Quadrats and Their Use 



201. Size and kinds. The unit size of quadrat is the meter, and when 

 the term is used without quaHficatien, it refers to the meter quadrat. To 

 make them strictly comparable, and exactly divisible, unit quadrats are 

 always grouped in squares ; thus a major quadrat is a square of four units, 

 and a perquadrat one of sixteen units, or four meters square. Quadrats of 

 greater size are necessary in woodland and forest, where the rule, however, 

 is that the woody plants alone are recorded for the whole quadrat, the her- 

 baceous growth being listed or mapped for but one or two representative 

 units. For special purposes, quadrats of 3, 5, 6, etc., meters may be used, 

 but they are much less convenient. Quadrats are further distinguished with 

 respect to their use. A list quadrat is one in which the plants are merely 

 listed and the number of individuals of each species indicated. Chart 

 quadrats are those in which the area concerned is accurately mapped on 

 plotting paper. Both list and chart quadrats are rendered permanent by 

 careful labeling, so that their changes can be followed from year to year. 

 The greater value of the chart causes practically all permanent quadrats 

 to be of this type, and for the same reason only permanent chart quadrats 

 are converted into denuded ones. 



202. Tapes and stakes. The lines for marking out quadrats are made 

 of strong white tape, 5/8 inches wide. This is doubled and sewed firmly 

 at both edges. Under moderate stretching, the tape is carefully marked 

 off into decimeters, and eyelets 5 mm. in diameter are set in at each end 

 and at the marks. This can readily be done by any shoemaker at slight ex- 

 pense. The usual lengths are one and two meters, as these are most 

 frequently used, and they can also be easily combined to make larger 

 quadrats. The tapes are slightly longer than one meter in order that the 

 distance between the end eyelets may be exact. The tapes of the larger 

 forest quadrats should be divided into lengths of one meter, as these permit 

 ready plotting and also make it possible to interpolate a meter quadrat for 

 the study of the undergrowth at any point. The intervals of the tape are 

 numbered from left to right, as conspicuously and clearly as possible. For 

 this a waterproof ink or paint is very desirable. For holding the tapes in 

 position, hatpins, nails, and meat-skewers have been used with more or less 

 satisfaction. The ideal stake, however, is one which holds the tape close 

 to the ground, and can be readily moved. It is merely a stout wire, 3 mm. 

 in diameter and 8 inches long, looped at the top, sharpened at the tip, and 

 with a small ring of solder 3 inches from the tip. 



