Nutritional Resources for Pollinators from Mass-Flowering Crop Cultivars

The scarcity of flowers to provide dietary nectar and pollen is a key driver of recent declines in pollinators in agricultural areas, but the planting of mass flowering crops enhances resources available to pollinators during parts of the year. This thesis investigates the nutritional resources provided for insect pollinators from various cultivars of two mass-flowering crops: short rotation coppice willow (Salix species) and oilseed rape (Brassica napus L.). Willow cultivars vary in the numbers of flowers produced per plant, as well as in the quantity of nectar sugar secreted by those flowers. There were neither qualitative nor quantitative differences in pollen production between the cultivars. Foraging insect pollinators showed preferences for cultivars with more rewarding flowers.