2 Viewpoint of Modern Ecology 



minimum needs. In other situations an ample supply of food and 

 light may be found, but the temperature may be so high as to exclude 

 all life. This is true in some hot springs. Certain soils of southwestern 

 United States are completely devoid of vegetation because of the 

 excessive amounts of salts or "alkaH." Death Valley on the Dieng 

 Plateau in Java is populated with plants but no animal life can exist 

 because of high concentrations of carbon dioxide issuing from subter- 

 ranean crevices. Such influences are prohibitory to life and others 

 are harmful without being lethal. In a complex natural situation it 

 is not always easy to discover the particular role each factor plays, 

 but we can be certain that in every situation dealings with the environ- 

 ment are inescapable. 



THE MEANING OF ECOLOGY 



The study of these interrelations of plants and animals with their 

 environment constitutes the science of ecology. The environment in- 

 cludes the influences of other plants and animals present as well as 

 those of the physical features. In order to investigate the exchanges 

 and interdependencies involved, it is necessary to have a knowledge 

 both of the organisms themselves and of the environments inhabited 

 by them. The ecologist must know the material with which he works. 

 He must have a grasp of the classification and the structure of plants 

 and animals, and he must understand what makes them tick. At 

 the same time the ecologist must be thoroughly aware of the nature 

 of the environment— both living and non-living. He must be familiar 

 with the different types of terrain on land and with the different 

 qualities of water in the ocean, lakes, and rivers. He must appreciate 

 the special environmental conditions provided by the various kinds 

 of vegetation. He must have a knowledge of the circulation of water 

 and air and of the dynamic processes going on in the soil. But the 

 taxonomy, morphology, and physiology of organisms and the physi- 

 ography of land and sea, although providing a necessary background, 

 do not form the central core of ecology. The ecologist focuses his 

 attention primarily on the interrelationships between the organism 

 and it J environment: 



Ecology 



Organism •<— > Environment 



The word "ecology" comes from the Greek "oikos," meaning "home" 

 or "estate"— hence, ecology is the study of the home, or how the house- 



