Microbial services : challenges for microbial ecologists in a changing world

Author Posting. © Inter-Research, 2008. This article is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Aquatic Microbial Ecology 53 (2008): 13-19, doi:10.3354/ame01220.Bacteria, archaea and other microbes have dominated most biogeochemical processes on Earth for >99% of the history of life, but within the past few decades anthropogenic activity has usurped their dominance. Human activity now impacts every ecosystem on the planet, necessitating a new socio-ecological view of ecosystem processes that incorporates human perceptions, responses, activities and ideas into ecology. The concept of ecosystem services is an important link between ecosystem processes and the social sphere. These include the provisioning, regulating, cultural and supporting benefits that ecosystems provide to enhance human well-being. Many ecosystem services are provided by microbes, initiating the concept of microbial services to society—an idea long appreciated by microbial ecologists. Experimental studies of the biodiversity–ecosystem function relationship emphasizing microbial functions are inconclusive, with increasing diversity sometimes being observed to enhance function, while at other times the opposite relationship has been found. A specific function addressing the role of bacteria in helping or hindering carbon storage in the deep ocean in response to iron fertilization is similarly uncertain. Bacteria respond positively to mesoscale iron additions in many cases, but in doing so, may retard carbon storage by decomposing sinking particles. Human exploitation of microbial services to enhance planetary sustainability must be based on focused studies of microbial processes in a human-dominated world.The work for this manuscript was supported in part by NSF OPP 0217282