Sentence:  Synecology has for the objects of its study, not individual organisms but biological <WSD>communities</WSD>, which are groups of organisms living in a given space, the properties of which space select a certain assemblage of organisms of definite autecological characteristics. Such <WSD>communities</WSD> are moreover not merely collections of organisms of restricted autecology, but tend to become organized by the biotic relationships that exist beteen the various individuals comprising the <WSD>community</WSD>. 
Meaning of the word marked with <WSD> tags:  A group of interdependent organisms inhabiting the same region and interacting with each other.