Common camas (Camassia quamash) response across an urban–rural gradient in coastal oak meadows in Greater Victoria, Canada

Abstract

Coastal oak meadows are fragmented across an increasingly urbanized landscape in Greater Victoria with implications for common camas (qʷɫəɫ/KȽO,EL/Camassia quamash) fitness. Common camas, frequently present in coastal oak meadows, is an ecologically important cultural keystone species that forms the foundation of one of the most important Indigenous food systems in the region. Previous research has examined how the pressures associated with urbanization shape plant community composition and structure, but how these pressures influence individual plant fitness remains unclear. To improve our understanding, we assessed environmental conditions and common camas growth and reproductive traits across an urban-rural gradient in Greater Victoria. We found that urbanization on this landscape alters several key environmental variables (namely increased trampling and soil compaction, and decreased soil depth, canopy cover, and soil phosphorus) and that common camas appears to be responding to these altered conditions with a reduction in growth and reproductive trait values. By targeting the identified pressures, management can work towards supporting more successful urban camas populations into the future.