Most flowering plants depend on biotic pollination and seed dispersal for successful reproduction. Pollination and seed dispersal are diffuse mutualistic interactions, in which many species with different effectiveness levels participate. However, anthropogenic habitat disturbance may hamper the impact of mutualists, jeopardizing plant recruitment. Important as it is, the effect of habitat transformation on the simultaneous contribution of pollinators and seed dispersers to plant reproduction remains little explored. Aiming to assess the effects of habitat transformation on the effectiveness of pollination and seed dispersal mutualisms, we studied a highly specialized system (a mistletoe interacting with one pollinator and one seed disperser), in native and transformed (abandoned Eucalyptus globulus plantations with native understory) habitats. Pollination and seed dispersal effectiveness landscapes were highly variable and did not differ between native and transformed habitats. Pollinator visitation and fruit removal, however, were higher at the transformed habitat probably favoured by a thick understory vegetation of shrubs and bamboo that provided additional resources to consumers. The resulting plant fitness was higher at the transformed habitat. Contrary to expectations, mistletoe reproduction was higher in the transformed habitat, suggesting that persistence of a highly specialized mutualistic is benefitted from the presence of a native understory vegetation that attracts mutualists and compensates for the often detrimental effects of habitat transformation.

This work was supported by the American Society of Mammalogists, the Scott Neotropical Fund program of the Cleveland Metroparks Zoo & Cleveland Zoological Society, the People’s Trust for Endangered Species, the Rufford Small Grants Foundation (10621-1), Idea Wild, and the Chilean Commission for Scientific and Technological Research (CONICYT; AT-24121082). Final writing of this article was supported by FONDECYT projects 3140528 and 11160152 (FEF).