The growth of Drosera intermedia in nutrient-rich habitats: the role of insectivory and interspecific competition

This study used field experiments to test whether insectivory confers any benefit on Drosera intermedia Hayne growing on lakeshores characterized by high sediment organic content and dense vegetation. Ramets were grown in pots containing organic shoreline sediment for one summer at Axe Lake, Ontario. Insect availability was controlled by nylon mesh. Biomass accumulated by D. intermedia was not affected by insect availability. In a second experiment, when D. intermedia was grown with ramets of Lysimachia terrestris (L.) BSP., the exclusion of insects significantly reduced the biomass accumulated by D. intermedia. These results suggest that insectivory may be important in reducing the effect of interspecific competition on D. intermedia growing in nutrient-rich habitats.