Table 1.

Summary of definitions used in this article

Term	Definition
Functional group	All organisms that directly contribute to the rate of a particular functional process in an ecosystem
Functional redundancy	The ability of one microbial taxon to carry out a process at the same rate as another under the same environmental conditions
Functional similarity	The ability of two microbial communities to carry out a functional process at a similar rate, regardless of differences in composition
Microbial composition	The richness, relative abundance, and phylogenetic structure of taxa in an assemblage
Microbial taxon	A group of phylogenetically related microbes
Resilience	The rate at which microbial composition returns to its original composition after being disturbed
Resistance	The degree to which microbial composition remains unchanged in the face of a disturbance
Physiological trait	A physiological characteristic that determines the contribution of a microbial taxon to a functional process
Physiological response curve	The function describing the relationship between the process contribution of a microbial taxon and disturbance intensity