A common garden experiment reveals increased warming and drought tolerance in urban invasive plant populations, indicating heightened invasion risks under ongoing climate change.
Key Points
To test whether urban environments drive adaptive evolution in the invasive plant Erigeron annuus, resulting in enhanced tolerance to simulated climate warming and drought.
Sampled Erigeron annuus populations along an urbanization gradient with varying temperature, soil moisture, and impervious surface cover in Zagreb, Croatia.
Conducted a common garden experiment exposing urban and rural plant lineages to control, warming, drought, and combined warming plus drought treatments.
Under control conditions, urban populations produced significantly less biomass than rural populations, reflecting a shift toward a conservative growth strategy.
Under experimental warming, drought, and combined treatments, urban lineages experienced significantly less growth impairment than rural counterparts or remained unaffected.
Stress tolerance positively tracked the degree of source-site urbanization, indicating that urban-driven exaptations enhance resilience to climate stressors.