PubMed · 2026-05-13
Urban wastelands where city sprawl meets invasive plants are a double blow for native wildflowers: together, urbanization and alien species drive native plant diversity down, with soil nitrogen overload as the key culprit pushing survivors toward fast-and-fragile growth strategies.
Native plant diversity was highest only when both urbanization levels and invasive plant diversity were simultaneously low — suggesting either pressure alone can undermine natives, but together the effect compounds.
Soil nitrogen emerged as the key mediating factor: elevated nitrogen driven by urban inputs and invasive species disrupted native plant communities more than any other soil variable measured.
Surviving native plants shifted toward 'acquisitive' leaf traits — longer leaves, higher leaf nitrogen, lower dry matter and carbon-to-nitrogen ratio — indicating a stress response that trades long-term resilience for short-term resource capture.