Modelling microbial food webs

M~crobial processes are now perceived to be an important component of the marlne food chaln Mathematical models present a quantltatlve means of analys~ng lnterspecles lnteract~ons within food webs Although detalled models of i n d ~ v ~ d u a l components of the m~crobial food web (bacteria, phytoplankton, protozoan predators) have been denved, t hen incorporation into large-scale food web models has yet to become commonplace Current models have confirmed the general importance of m ~ c r o b ~ a l food webs and that the speclflc inclusion of protozoan predators In models is often necessary to simulate the observed dynamics Simulat~ons have lnd~cated that the effect of the microb~al food web on the food chain may vary greatly depend~ng on imposed physical or b~ological conditions The manner in w h ~ c h nutrient regeneration from protozoan predators and ~ t s subsequent reutilisation by bacteria and phytoplankton 1s simulated IS an Important cons~deratlon Models employ equa t~ons of varying sophis t~cat~on, but deta~led recent formulations use a dual model currency of C and W Models have also Increased our understanding of the Interaction between grazlng and nutrient cycl~ng and the different behav~our of food chains and webs