Ecologic Study of Living Organisms 643 



III. ECOLOGY OF A PORTION OF A LAKE SHORE 



As an example of an ecologic study of a limited area, let us use a 

 portion of a shore of a fresh-water lake. Four stations designated as A, 

 B, C, and D are shown in Figs. 323 and 324. A thorough study of the 

 environmental conditions and total numbers of animals found in each 

 station (Fig. 323) will illustrate the problems of ecology. Note the dif- 

 ferences in the environmental conditions and populations of Stations A, 

 B, and C. Contrast these with Station D, which is a small, shallow 

 pool located several feet from the lake but connected with it when wave 

 action in the lake is particularly strong. A square foot of the bottom 

 was studied carefully in each station. How can you account for such 

 variations in the numbers and types of organisms in these stations? 

 List as many factors as you can which you think might be responsible 

 for such distributions. 



5hrab5> 

 Qrass- 



Lake 



Fig. 324. 



-Diagram showing the location of Stations A, B, C, and D of an ecologic 

 study of a fresh-water lake (see Fig. 323.) 



A very good method of studying ecology is to select some desirable 

 area, either land or water, and make a careful and detailed study of it 

 yourself. You will also find quite a seasonal change in the animal and 

 plant population of each area when studied at different times of the 

 year. 



IV. ECOLOGIC STUDY OF A PORTION OF YOUR CAMPUS 



In order to understand the principles of ecology and the many fac- 

 tors involved in determining the distribution of living organisms, it is 

 suggested that you study a small portion of your campus , following the 



