Urbanization alters plastic responses in the common dandelion

Urban environments expose species to contrasting selection pressures relative to rural areas due to altered microclimatic conditions, habitat fragmentation and changes in species interactions. To improve our understanding on how urbanisation impacts selection through biotic interactions, we assessed differences in plant defence and tolerance, dispersal and flowering phenology of a common plant species (Taraxacum officinale) along an urbanization gradient and their reaction norms in response to a biotic stressor (i.e. herbivory). We raised plants from 45 lines collected along an urbanization gradient under common garden conditions and assessed the impact of herbivory on plant growth (i.e aboveground biomass), dispersal capacity (i.e. seed morphology) and plant phenology (i.e. early seed production) by exposing half of our plants to two events of herbivory (i.e. grazing by locusts). Independent from their genetic background, all plants, consistently increased their resistance to herbivore...