Chapter 9 Microbial Ecology Microbial ecology = ? Environmental microbiology The term microbial ecology is now used in a general way to describe the presence and distributions of microorganisms. Microbial ecology is the the study of the behavior and activities of microorganisms in their natural environments.Chapter 9 Microbial Ecology Microbial ecology = ? Environmental microbiology The term microbial ecology is now used in a general way to describe the presence and distributions of microorganisms. Microbial ecology is the the study of the behavior and activities of microorganisms in their natural environments