From controversy to consensus: the indirect interference functional response

摘要

Theoretical debate between advocates of the prey-dependent and ratio-dependent functional responses has given way to an understanding that most functional responses exhibit some form of predator dependence (ABRAMS & GINZBURO 2000). The intermediate models of BEDDINGTON-DEANGELIS (BD; DEANGELIS et al. 1975) and HASSELL-VARLEV (HvH; HASSELL-VARLEY 1969) capture some of the properties of ratio dependence without the extreme assumption of total prey sharing. When and how to use these intermediates remains a mystery; this uncertainty prevents prediction of: (1) the equilibrial response of trophic systems to enrichment; (2) the length of trophic chains; and (3) the stability of trophic systems. Whether the goal of an applied project is to keep population densities low (e.g., when managing a pest or counteracting an algal bloom) or to maintain sufficient population densities (e. g., when conservation is the goal), functional response assumptions directly impact the decision-making process. With the eventual goal of using predator-prey equations to aid in man agement and conservation efforts, some guidance in choosing an appropriate functional response needs to be provided. We delineated the strengths and weaknesses of the preyand ratio-dependent forms and suggest a novel predatordependent form that preserves the viable attributes of both extremes.