Figure 1. A conceptual model for the effects of land use intensification on the specialization of interactions in plant-herbivore networks.

First, human land use is expected to have a negative impact on the species richness of native host species, while facilitating the invasion and establishment of exotic plant species. Consequently, plant assemblages under higher levels of land use intensity are predicted to have a higher proportion of exotic plant species. Both land use intensification and the increase in the proportion of exotic host plant species would promote the loss of herbivore species at the local scale, but with greater negative impacts on the specialist herbivores than on generalists. Because of the greater reduction in the number of specialist herbivorous species, the proportion of monophagous herbivores is predicted to decrease, whereas the network connectance is predicted to increase with land use intensification and higher proportions of exotic host plant species.