Mistletoes are a group of flowering plants that have developed a parasitic lifeform through complex eco-evolutionary processes. Despite being considered a pest, mistletoes represent a keystone forest resource and are involved in complex plant-plant and plant-animal interactions. Their parasitic lifeform and specialized ecological interactions make mistletoes an ideal model with which to understand the effects of anthropogenic disturbances in a changing world. The accelerated growth of the human population has altered all ecosystems on Earth, leading to biodiversity loss. Land-use changes (involving habitat loss, fragmentation, degradation, and transformation processes) can alter the ecological scenario for mistletoe by altering hosts, mutualists, and nutrient cycling. Those changes may have large consequences at the community level, changing the spatial structure of mistletoes, as well as interaction effectiveness, facilitation process, interaction disruption, and novel interactions with invasive species, leading to non-analog communities in the long run. Furthermore, climate change effects operate on a global scale, enhancing the effects of land-use changes. As temperatures increase, many species would alter their distribution and phenology, potentially causing spatial and temporal mismatches. But more critical is the fact that water stress is likely to disrupt key ecological interactions. Thus, mistletoes can provide valuable insights for what we can expect in the future, as a result of human disturbances. Key words: climate change, eco-evolutionary dynamics, facilitation, land-use change, spatial mismatch, temporal mismatch. Le gui comprend un groupe de plantes a fleurs qui ont developpe une forme de vie parasitaire grace a des processus ecoevolutifs complexes. Bien qu'il soit considere comme un parasite, le gui constitue une ressource forestiere fondamentale et il est implique dans des interactions plantes-plantes et plantes-animaux complexes. Sa forme de vie parasitaire et ses interactions ecologiques specialisees font du gui un modele ideal pour comprendre les effets des perturbations anthropiques dans un monde en changement. La croissance acceleree de la population humaine a modifie tous les ecosystemes de la Terre, entrainant une perte de diversite. Les changements d'utilisation des terres (impliquant la perte, la fragmentation, la degradation et la transformation des habitats) peuvent modifier le scenario ecologique du gui en affectant ses hotes, ses mutualistes et le cycle de ses nutriments. Ces changements peuvent avoir des consequences importantes a l'echelle de la communaute, en modifiant la structure spatiale du gui, l'efficacite des interactions, le processus de facilitation, l'interruption des interactions et l'etablissement de nouvelles interactions avec des especes envahissantes, donnant lieu a long terme a des communautes non analogues. De plus, les effets des changements climatiques se repercutent a l'echelle mondiale, accroissant les effets des changements d'utilisation des terres. Avec l'augmentation des temperatures, de nombreuses especes pourraient modifier leur distribution et leur phenologie, ce qui pourrait provoquer des desequilibres spatiaux et temporels. Mais le fait que le stress hydrique puisse perturber des interactions ecologiques cles est encore plus critique. Ainsi, le gui peut donner un apercu precieux de ce que nous pouvons attendre de l'avenir, en consequence des perturbations humaines. [Traduit par la Redaction] Mots-cles : changements climatiques, dynamique ecoevolutive, facilitation, changement d'utilisation des terres, desequilibre spatial, desequilibre temporel., Introduction Among the flowering plants, mistletoes are a particularly fascinating group not only because of their parasitic lifeform, but also because of their importance in the ecosystem (Watson 2001; Mellado [...]