THE QUADRAT METHOD IN TEACHING ECOLOGY 



275 



in only the moister portion of the quadrat in 1918 is quite 

 evident. The summer was once of severe drought. Fropi May 

 I to September 1 the precipitation was only 52% of the normal. 

 Indeed the area yielded only 26% of its fonner quota of plants 

 and these were less than half their normal size. 



Quadrats 1 and 2, which were adjacent, were located in such 

 a manner that the adjoining portions extended over a small 

 ridge and the other ends into the Dondia and Atriplex zones. 



Fig. 5. Quadrat 5 charted in October, 1917 (left) and 1918. A^Atriplex 

 hastata, D = Dondia depressa, 'Di = Distichlis spicata. 



These are shown in figure 6. In 1916 the presence of Distichlis 

 on the ridge indicated that it was an old eroding area. In 1917 

 numerous rhizomes were exposed and by 1918 living plants had 

 entirely disappeared. The invasion of Dondia further into both 

 quadrats in 1917 is quite apparent as is also the much greater 

 abundance and extent of Atriplex. The small amount of Dondia, 

 the reduced number of Atriplex and its withdrawal to the more 

 stable portions of the area in 1918 are readily apparent. This 

 agrees with quadrat 5 and is verified by several others. 



Such an analysis by students teaches them to think in terms 

 of vegetation and environment. The time employed in charting 

 the quadrats is seldom over half of a day, for two students are 



