"The decline or extinction of native species involved in biotic interactions (i.e., the disruption of interactions) can cause significant changes in ecosystem structure and/or functioning. Since the distribution, population dynamics and evolution of many species depend on species inter-relationships, changes (or loss) of such interactions can lead to disproportionately large, irreversible, and often negative alterations of ecosystem processes. Despite short-term consequences of the disruption of interactions, the current knowledge about its medium and long-term costs are limited, not only for the species regeneration but also for the functioning of the whole ecosystem. We can observe the causes and the final consequences of a disruption in a given plant-animal interaction, but the ecological and demographic processes that underlie such patterns remain unknown. This project will take a multidisciplinary approach and use recent modelling techniques (Individual based modelling and spatial-explicit population models) to study the direct and indirect consequences of a mutualism disruption within a comprehensive way including the spatial pattern generated by seed disperser to the plant spatial pattern and demographic consequences produced by such plant pattern. The methodological innovation of this project is the integration of previously collected data into two interacting Spatial-Explicit Population Models which describe an explicit plant-animal interaction. This type of simulation model allows for taking a first principle approach in which natural history and field observations are used to deduce the causal relationships among components of the natural systems and the resulting system dynamics."