  Food webs with intraguild predation (IGP) are widespread in natural habitats.
Their adaptation and resilience behaviour is principal for understanding
restructuring of ecological communities. In spite of the importance of IGP food
webs their behaviour even for the simplest 3-species systems has not been fully
explored. One fundamental question is how an increase of diversity of the
lowest trophic level impacts the persistence of higher trophic levels in IGP
relationships. We analyze a 3-species food web model with a heterogeneous
resources and IGP. The model consists of two predators directly coupled via IGP
relation and indirectly via competition for resource. The resource is
subdivided into distinct subpopulations. Individuals in the subpopulations are
grazed at different rates by the predators. We consider two models: an IGP
module with immobilization by the top predator and an IGP module with species
turnover. We examine the effect of increasing enrichment and varying
immobilization (resource transfer) rate on a stable coexistence of predators
and resources. We explore how the predictions from the basic 3-species model
are altered when the IGP module is extended to multiple resource
subpopulations. We investigate which parameters support a robust coexistence in
the IGP system. For the case of multiple subpopulations of the resource we
present a numerical comparison of the percentage of food webs with stable
coexistence for different dimensionalities of the resource community. At low
immobilization (transfer) rates our model predicts a stable 3-species
coexistence only for intermediate enrichment meanwhile at high rates a large
set of stable equilibrium configurations is found for high enrichment as well.
