Basic Aspects of Ecology

The interactions among organisms and the environment determine their distribution and abundance 

These blurred boundaries reflect the fact that every small ecosystem exists within larger ecosystems. Each ecosystem blends into the next through a transitional zone called ecotone, which contains many of the species and characteristics of the two adjacent systems, plus unique species adapted to the special conditions of the interphase. 

The biosphere has many parts and subparts, as deciduous forest and rain forest, grassland and dessert, seacoast and ocean floor, which provide a myriad of habitats or actual places where organisms live. The Earth s major ecosystems are called biomes, which have characteristic types of organisms. Some usefiil definitions are listed in Table 7.4. 

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