COS 4-6
Climate change induced shifts in abiotic resources may alter pollination success: A test with Mertensia ciliata (Boraginaceae)
Rising temperatures and earlier snowpack melting due to climate change have been linked to alterations in the distribution, phenology, growth, and reproduction of many plants and animals. As individual species respond differently to climate change, critical ecological relationships, such as those between plants and pollinators, may be disrupted. Warmer springs and earlier snowpack melting are likely to alter the timing of plant reproduction (i.e. phenology) and also influence water availability in the soil during the growing season. I am investigating the potential effects of climate change on plant-pollinator mutualisms, as mediated by plant responses to water availability and phenological responses to temperature.
My initial research is focused on examining the impact water availability has on the pollination and subsequent reproductive success of the tall-fringed bluebell, Mertensia ciliata (Boraginaceae). In 2012, I began a multi-year water manipulation experiment with a natural M. ciliata population (2,992 m. a.s.l.) using a randomized block design with water addition, water reduction, and control treatments. In 2013, I added a second, higher elevation population (3,143 m. a.s.l.), in order to determine whether results at the lower elevation explain observed M. ciliata range shifts.
Results/Conclusions
Initial results indicate that reducing soil water availability negatively impacts M. ciliata flower size (corolla width and length) and seed set. Pollinators also visited a higher proportion of flowers available in the control and water addition treatments than in the water reduction treatments. While results from 2012 indicated that flowering was contingent on water availability, with more flowering plants in the water-added plots than in the other treatments, in 2013 the opposite trend was observed in the high elevation site. There was no treatment difference in flowering at the low elevation site. Continuation of this experiment for multiple years is allowing assessment of how water-mediated changes in flowering influences the rate of pollinator visitation.