QUADRATS 



165 



203. Locating quadrats. In staking a quadrat, the end tapes are in- 

 variably placed so that the numbers read from left to right, and the side 

 tapes so that they read down. In mapping, a fifth tape is stretched parallel 

 to the top, and as each decimeter strip is marked, the outer tape is shifted 

 to delimit the new strip. Indeed, the side tapes can be placed alone, and the 

 plotting tapes moved down one at a time as the mapping proceeds, but it 

 is usually more satisfactory to locate the quadrat exactly and to square it 

 first, a task most easily done by enclosing the whole quadrat, and then using 

 a fifth tape. In the case of list quadrats in open vegetation, the measuring 

 strip is unnecessary, but as a rule it facilitates counting, as well as mapping. 



Fig. ."50. Mapping a major quadrat on Mount Garfield at 3,600 m. 



The List Quadrat 



204. Description. This, as the simplest form of quadrat, is employed 

 primarily to ascertain the abundance of species in a formation or during 

 a particular aspect of it. Since this can be obtained readily from the 

 chart, the list quadrat has fallen more and more into disuse, except where it 

 is desired to determine abundance alone, or to aid in deciding whether a 

 chart is really representative. The size depends almost wholly upon the 

 nature of the vegetation. When the number of trees is to be determined, a 

 quadrat of 10 or 50 meters is necessary. In ordinary herbaceous forma- 

 tions, the usual size is 2 meters, while the meter quadrat is used when the 



