PARENT SESSION
Symposium 2: Soil Biodiversity: Scaling from microbe to ecosystem
Organized by: A Fitter, C Kennan, and H Jones
Monday, August 8, 8:00 AM - 11:30 AM, Meeting Room 517 B, Level 5, Palais des congrès de Montréal
Is an understanding of microbial population and community ecology important for predicting ecosystem function?
Firestone, Mary*,1, Bohannan, Brendan2, 1 University of California and, Berkeley, CA, USA2 Stanford University, Stanford, CA, USA
ABSTRACT- While it is generally accepted that microorganisms (here referring to bacteria and fungi) are centrally important to the functioning of ecosystems (e.g. through mediating nitrogen-cycling, decomposition, sulfur-cycling, etc), it is commonly believed that, unlike plants and animals, the population and community ecology of microbes is generally irrelevant to ecosystem processes. This is assumed to be true because of the unique biology of microorganisms, particularly their very large population sizes, rapid growth rates, high rates of dispersal, low extinction rates and high levels of functional redundancy. Although these traits have been assumed to be universally characteristic of microbes, the evidence for this is scant. Recent research suggests that in fact these traits are not universal attributes of microbes, and thus that microbial processes at ecological scales below that of the ecosystem may be important to ecosystem function. We will argue that the relationship between microbial population/community processes and ecosystem functions is sensitive to how one defines microbial taxa and how one delineates an ecosystem process. We will present data indicating that microbial communities are not interchangeable, but rather are the unique product of the integrated ecosystem characteristics and as such, frame the function of the ecosystem. We suggest that debate over the relationship between ecosystem function and microbial population and community ecology be recast. Rather than ask the question is knowledge of microbial population and community ecology useful in understanding or predicting the function of ecosystems? we suggest that the debate focus instead on the question at what level of resolution and for what ecosystem processes are population and community processes likely to be important in ecosystem functions?
Key words: ecosystem function, microbial community ecology, microbial population ecology