Bottom-Up Limitation of Predaceous Arthropods in a Detritus-Based Terrestrial Food Web

Abstract

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Opportunistic predator prefers habitat complexity that exposes prey while reducing cannibalism and intraguild encounters

“…That same analysis did not uncover effects of habitat structure on the density of herbivorous prey, but not all types of potential prey were incorporated into the analysis and, as aptly noted, there are cases where arthropod predators accumulate in response to high densities of detritivores (Chen and Wise 1999;McNabb et al 2001;Halaj and Wise 2002;Oelbermann et al 2008). Indeed, other studies have shown that enhancing the decomposer community plays a role in the establishment of robust populations of predators living up in the vegetation (Scheu 2001;Rypstra and Marshall 2005).…”

“…Particularly difficult to tease apart is the role of habitat complexity in interactions between predators and prey (Halaj and Wise 2002;Miyashita and Takada 2007;Birkhofer et al 2008). In most habitats, the living and dead vegetation create complexity that are also resources for herbivores and detritivores fueling the rest of the food web (Price et al 1980;Denno and McClure 1983;Wyman 1998;Chen and Wise 1999). In addition, habitat complexity can influence the hiding, escape, and attack tactics of animals on both sides of the predator-prey equation (Crowder and Cooper 1982;Uetz 1991;Finke and Denno 2002;Legrand and Barbosa 2003;Warfe and Barmuta 2004).…”

Utilization of prey from the decomposer system by generalist predators of grassland

“…The relative importance of resource control and predator control in terrestrial food webs is still disputed (Moran et al 1996;Halaj and Wise 2002;Moran and Scheidler 2002). Although soil animal communities are often considered to be bottomup controlled (Strong 1992) empirical evidence is scarce (Scheu and Schaefer 1998;Chen and Wise 1999;Salamon et al 2006). To investigate the role of resource supply the availability of resources is manipulated and changes in the density of consumer taxa are measured; if a taxon responds with an increase in density it is assumed to be bottom-up controlled.…”

“…Wolf spiders are important generalist predators in terrestrial ecosystems (Edgar 1971;Wise 1993) feeding on herbivorous, detritivorous and predaceous arthropods (Edgar 1969;Wise 1993;Chen and Wise 1999). Like most generalist predators, spiders consume prey from both the detritivore-based and the herbivore-based subsystem and therefore link both subsystems (Polis and Strong 1996;Wise et al 1999;McNabb et al 2001;Halaj and Wise 2002;Miyashita et al 2003;Wise 2004;Wise et al 2006).…”

Interactions between a detrital resource pulse and a detritivore community

“…Investigations in diverse systems have documented generally positive effects of detrital resource enrichment on detritivore immigration, activity and reproduction (McBrayer et al 1977;Seastedt 1984;Wise 1997, 1999;Reynolds et al 2003). For example, Chen and Wise (1999) demonstrated that populations of forest litter detritivores increased under experimentally pressed supplementation with mushrooms, potatoes and fruit fly medium. These observations are consistent with conceptual and theoretical models suggesting broad resource limitation of detritivore populations in most ecosystems (Hairston et al 1960;Pimm 1982;Nisbet et al 1997).…”