ECOLOGY is the study of organisms in their environment. Ecology is one of the most complex scientific disciplines because of the myriad of organisms’ interactions. Using microbes to study ecology may provide clues to how complex ecosystems operate because bacteria are small so large populations can be studied and quick to reproduce compared to larger organisms. A better understanding of ecology may help us better manage Earth and its dwindling renewable resources and to protect global ecological systems.

GLOBAL ECOLOGY – Microbes play important global roles:

•  Global Geochemical Cycles
             o  Carbon
             o  Nitrogen
             o  Iron,
             o  Sulfur
•  El Niño – what role do microbes play in El Niño?
•  Global Warming – The average temperature of the Earth has been steadily increasing over the past one hundred years. What role do microbes play in this global warming trend?
•  Gaia – the Earth’s biosystem is known to some as Gaia. Because microbes are responsible for most of the cycling of elements, they are the foundation of this system.

HUMAN ECOLOGY – The study of simple microbial communities may shed light on one of the most complex (and for most of us most fascinating) communities – the microbial community within a human being. We are hosts to billions of microbes which colonize our intestinal tracts, our skin, hair, teeth. Sometimes microbial colonization causes us problems when disease results. Some scientists have joked that humans are microbes’ invention to move around.

POPULATION INTERACTIONS – Microbes interact with plants and animals and each other in myriad ways with large plants and animals having hundreds of associations with different microbial species.

•  Plant-microbe Interactions
       o symbiosis – e. g. Rhizobium which converts nitrogen to a form that can be used by plants.
       o disease
•  Animal-microbe Interactions
       o symbiosis – e.g. probiotics = beneficial gut microflora
       o disease
•  Microbe-microbe Interactions – e.g. lichens