Data from: Variation in flower size and shape of Impatiens capensis is correlated with urbanization in Montreal, Canada

Urbanization is changing the conditions in which many species live, forcing them to adjust to these novel environments. Floral size and shape are critical traits for the reproduction of plants pollinated by animals as they are involved in the attraction of pollinators and in efficient pollination. Variation in size and shape could be affected by urbanization via its modification of the abiotic environment (habitat fragmentation, water availability, temperature, soil properties), or via its impact on the biotic environment of plants (pollination, herbivory). Although numerous studies have assessed the impact of urbanization on pollinator communities and on many plant traits, few have investigated its impact on floral size and shape while quantifying the proportion of the total urbanization effect that is due to biotic interactions. In this study, we tested if urbanization and pollinator visitation rates affects the flower shape of the spotted jewelweed, Impatiens capensis. We quantified size and shape of flowers in frontal and profile views using geometric morphometrics for 228 individuals from six populations from the region of Montreal, Canada. Pollinator visitation rates were estimated at each site and the main pollinators were found to be bumblebees, honeybees and hummingbirds. We found that floral size and shape are significantly correlated with urbanization as measured by the amount of vegetation in the surrounding environment of the plants (mean normalized vegetation index, NDVI) and by the visitation rates of bumblebees and honey bees. Partitioning of the total flower shape variation suggests that urbanization affects flower shape through abiotic factors and via its impact on pollinator visitation rates. While further studies from other cities are necessary to confirm the role of urbanization in shaping the floral shape of I. capensis, these results support the idea that urbanization could affect flower shapes.城市化正改变诸多物种的生存环境，迫使它们适应这类全新的生境。花的大小与形状是动物传粉植物繁殖的关键性状，二者参与传粉者的吸引与高效传粉过程。花的大小与形状的变异可能受城市化影响：城市化可通过改变非生物环境（如生境破碎化、水分可获得性、温度、土壤特性），或通过调控植物的生物环境（如传粉、植食作用）来发挥作用。尽管已有大量研究评估了城市化对传粉者群落及诸多植物性状的影响，但鲜有研究在量化城市化总效应中由生物相互作用贡献的比例的同时，探究其对花大小与形状的作用。本研究旨在探究城市化与传粉者访问率是否会影响斑点宝石凤仙（Impatiens capensis）的花形。我们采用几何形态测量学（geometric morphometrics），对加拿大蒙特利尔地区6个种群的228个个体的花，分别从前视图与侧视图进行大小与形状量化。我们在每个样地估算了传粉者访问率，并确定主要传粉者为熊蜂、蜜蜂与蜂鸟。研究发现，花的大小与形状与城市化水平显著相关，该水平可通过植物周边环境的植被量（平均归一化差异植被指数（Normalized Difference Vegetation Index, NDVI））以及熊蜂与蜜蜂的访问率来衡量。对花形总变异的分解结果显示，城市化可通过非生物因子，以及通过影响传粉者访问率两条途径改变花形。尽管后续仍需在其他城市开展相关研究以验证城市化对斑凤仙花（I. capensis）花形塑造的作用，但本研究结果支持"城市化可影响花形"这一观点。