Search for: All records

Abstract Understanding how urbanization affects plant interactions with pathogens and herbivores is important for clarifying how changes in land use, climate and biodiversity affect ecological and evolutionary processes, and for managing urban plants to maximize ecosystem services. We performed a systematic literature review of relationships between urbanization and pathogens or pests of wild and cultivated plants. We identified k = 171 relationships from n = 54 studies in which pathogen or pest abundance was quantified in both urban and non-urban areas and summarized their distribution across taxa, geographic regions and directions and mechanisms of effects proposed by the authors. Most studies featured tree hosts and their arthropod pests or fungal pathogens. Grasses and forbs were the next most commonly studied hosts, followed by crops and shrubs. We then performed a meta-analysis limited to trees, which had the most studies with sufficient statistical information (k = 55 relationships, n = 14 studies). In that meta-analysis, we found no overall effect of urbanization on tree pest or pathogen abundance. However, there was a significant effect of pest/pathogen, with arthropod pests trending towards lower abundance in urban areas and fungal pathogens trending towards higher abundance. Drawing on literature from the broader fields of urban ecology, disease ecology and plant pathology, we synthesize our findings and offer insights into mechanisms by which urbanization influences disease and herbivory in wild and cultivated plants. We conclude by identifying research gaps, with the goal of informing management strategies that prioritize food security, environmental health and global biodiversity. This article is part of the theme issue ‘Wild plant pathosystems’. 

Abstract Behavioural plasticity is a major driver in the early stages of adaptation, but its effects in mediating evolution remain elusive because behavioural plasticity itself can evolve.In this study, we investigated how male Trinidadian guppies (Poecilia reticulata) adapted to different predation regimes diverged in behavioural plasticity of their mating tactic. We reared F2 juveniles of high‐ or low‐predation population origins with different combinations of social and predator cues and assayed their mating behaviour upon sexual maturity.High‐predation males learned their mating tactic from conspecific adults as juveniles, while low‐predation males did not. High‐predation males increased courtship when exposed to chemical predator cues during development; low‐predation males decreased courtship in response to immediate chemical predator cues, but only when they were not exposed to such cues during development.Behavioural changes induced by predator cues were associated with developmental plasticity in brain morphology, but changes acquired through social learning were not.We thus show that guppy populations diverged in their response to social and ecological cues during development, and correlational evidence suggests that different cues can shape the same behaviour via different neural mechanisms. Our study demonstrates that behavioural plasticity, both environmentally induced and socially learnt, evolves rapidly and shapes adaptation when organisms colonize ecologically divergent habitats.