One major consequence of modern global change is that many plant and animal species world-wide are displacing their geographic ranges in response to climate change, rural lands abandonment and natural areas protection. Plant-animal interactions play a key role in these expansion processes, being able to favor these movements (e.g. Long-Distance Dispersal mediated by frugivorous animals) or constraining them (e.g. seed predation by antagonists). In my thesis project we explore how diverse interaction networks at the individual level are being reshaped under a plant range expansion scenario. In addition, we want to understand the role of individual plant traits in the structuring of interaction networks, and the consequences of dispersal service during plant movements in genetic terms. As a study model we have selected Juniperus phoenicea, which has notably expanded its distribution in the Reserva Biológica de Doñana since the protection of this natural area. We combine experimental field data and molecular laboratory techniques (DNA-Barcoding and Maternal Genotyping) with novel analysis tools such as individual network models and multilayer networks. With this thesis we intend to advance the current knowledge on how plant movements occur at a local scale, focusing on the role and consequences of diverse interaction partners.