The effect of urbanization on reproduction and selection on floral traits in the wildflower, Linaria vulgaris
Urbanization-induced changes to the environment may affect reproduction and evolution within plant populations. These changes include habitat fragmentation, which may reduce genetic diversity within urban populations, and decreased pollinator activity, which may increase competition for pollinators between plants. To test if these changes could influence reproduction and selection on reproductive traits within urban plant populations, I performed hand-pollinations and measured phenotypic selection on floral traits in the self-incompatible plant, Linaria vulgaris, along urban to rural gradients. I found that compatible mate availability hindered reproductive success within urban populations and evidence of the breakdown of self-incompatibility in urban and rural populations. I found no difference in selection on floral traits between urban and rural populations, but floral traits were larger in urban areas. My study suggests that floral traits will not continue to diverge between urban and rural populations, however mate availability maybe an underappreciated limit on reproduction in urban populations.