Pollinators and Global Warming

Pollinators, global warming, and plant mating systems

 

Earlier studies with A. coerulea indicated significant variation in selfing rate among plants within populations and identified some of the plant and floral traits that affected selfing rate (Brunet and Eckert 1998, Functional Ecology). Geitonogamous selfing contributed the majority of the selfing in this plant species while autogamous selfing was negligible (Brunet and Sweet 2006, IJPS). Both floral display size and pollinator type affected outcrossing, with an increase in outcrossing rate with increased hawkmoth abundance and larger floral displays, and both factors affected the levels of geitonogamous selfing (Brunet and Sweet 2006, Evolution). We concluded that selfing in this plant species was most likely a non-adaptive consequence of having more than one flower open at the same time on a plant (Brunet and Sweet 2006, Evolution; Brunet and Sweet 2006, IJPS).

We later quantified the variation in pollination biology and floral traits among populations over part of the range of A. coerulea and looked for correlations between floral traits and pollinator species among populations (Brunet 2009, Annals of Botany). We then examined the impact of pollination and mating system on the geographical variation in genetic structure of A. coerulea populations (Brunet et al. 2012, IJPS). 

Finally, we examined the impact of water availability and temperature on floral traits that affected the selfing rate (Van Etten and Brunet 2013, IJPS) and water availability on floral traits that affected pollinator attraction (Brunet and Van Etten 2019, IJPS, Special Issue on Floral Evolution). We also determined the impact of global warming in high altitude habitats on flowering phenology (Brunet and Larson-Rabin 2012).

More recently (Keefover-Ring et al. 2021) we described the floral bouquet of the Rocky Mountain columbine and examined the impact of reduced water at different temperatures on floral scent composition. We detected genetic differentiation in floral scent among the three populations examined, suggesting adaptation to the three environments that differ both abiotically and biotically (abundance of distinct pollinators). We observed phenotypic response to water for many of the volatile organic compounds (VOCs) making up the floral bouquet and genetic differentiation in the phenotypic response of the VOCs to water availability, the latter limiting general prediction of the response of VOCs to climate change in this plant species.