Abstract

Pollinators decisions on which flowers to visit are based on the advertisements and rewards offered by individual flowers. To test the importance of flower morphology in attracting pollinators I manipulated both overall corolla size and corolla symmetry of the British wildflower Epilobium angustifolium. Two hypothesis were investigated, the ‘symmetry’ hypothesis, in which symmetrical flowers are expected attract more frequent pollinator visits, and the ‘size of floral display hypothesis’, where visitation rates would increase with an increase in floral size. The manipulation thus allowed investigation of the effect of corolla size and symmetry on pollinator visitation, pollen arrival and seed production, and the relationships between these variables.

Main findings of the investigation; both flower symmetry and petal area were found to have significant positive direct effects on visitation, pollen and seed production. Pollen had a significant direct effect on seed production. Symmetry and petal area have significant positive indirect effects via pollen. Notably, visitation had a positive, but statistically weak, direct effect on pollen.

Course: Master of Philosophy - MPhil

Date Deposited: 2017-05-10

URI/permalink: https://library.port.ac.uk/dissert/dis12880.html