An urban evolved invasive plant tolerates experimental climate change
S. Luke Flory, Drew Hiatt, Jesse Borden, Damjana Levačić, Sven JelaskaSocietal Impact Statement
Urbanization may drive invasive species evolution, resulting in greater invasion risks as global conditions change. We compared urban populations of the invasive
Summary
Novel urban conditions are hypothesized to drive evolution of invasive species, and urban evolved invaders are predicted to be more tolerant of climate change. We tested these hypotheses with the invasive plant
Urban study sites had lower soil moisture, were hotter, and had more impervious surface than rural sites. In a common garden experiment under control conditions, plants from urban populations produced significantly less biomass than populations from rural sites, suggesting urban population evolution towards a conservative growth strategy. Under experimental warming, drought, and warming + drought treatments, urban populations were unaffected or were less negatively affected by the simulated climate change treatments than rural populations. These differences tracked the urban–rural gradient, where invasive plant population tolerance to climate change treatments increased with the degree of urbanization at source sites. Our results indicate that an invasive plant evolved in response to urbanization, resulting in exaptations that enhanced tolerance to experimental climate change. Consequently, urbanized invaders may present greater invasion risks as surrounding regions become hotter and drier.