Chapter 2 - When Microscopic Organisms Inform General Ecological Theory

摘要: Summary Free-living protists and very small metazoans, such as meiofauna or mesozooplankton, are extremely abundant in aquatic habitats they play a key role numerous ecosystem processes, including nutrient cycling supplying energy to higher trophic levels. Assessing their ecological roles is needed understand natural systems own right, but study can also be used inform test general theories. Organisms smaller than 2 mm size ideal candidates for laboratory field studies with theoretical focus, we illustrate this point published examples of pioneering recent work which the use protozoans, fungi metazoans has informed theories within population community ecology more synthetic that span different levels biological organisation (e.g. biodiversity–ecosystem functioning relationships metabolic theory ecology). These literature highlight how been stimulated by research vice versa. Studies species might sufficiently universal applied larger organisms extension could offer insights into ecosystems operate. In main part chapter, discuss whether these worlds represent world giving three case related concepts topics: temperature-size rule (TSR), allometric scaling abundance relationships. first two studies, if differ from metazoans; all explore patterns observed vary those detected consequences have detecting unifying principles. We combination our data predictions TSR scaling. case, found mechanisms generate phenomenon adult at low temperatures likely fundamentally protozoans multicellular animals. second study, regressed body large set against abundance. single-celled differed regard allometries both groups metazoans. cases, there evidence extrapolations need treated some caution. final what extent among (aquatic fungi) similar organisms.