ROSEMARY MACKAY FUND ARTICLE: Ecological stoichiometry of trophic interactions in the benthos: understanding the role of C:N:P ratios in lentic and lotic habitats

Abstract

This paper considers how the theory of ecological stoichiometry may be applied to issues of importance to benthic ecologists. Ecological stoichiometry considers both the causes of elemental (C: N:P) imbalances between trophic levels and their consequences on foodweb dynamics (e.g., predator– prey interactions) and ecosystem processes (e.g., nutrient cycling). Elemental imbalances are created between consumers and their food, in part, by the accumulation of C relative to other nutrients (N and P) in benthic organic matter as a result of the deposition of detritus and/or unbalanced growth in aquatic producers. High C:N and C:P ratios in food material can reduce growth and reproduction and alter related processes such as nutrient release in benthic consumers. By affecting consumer metabolism, elemental imbalances may affect population dynamics, trophic interactions, and gross transfer efficiencies in benthic systems. Future work is needed to quantify the frequency and magnitude of elemental imbalances, to determine why elemental ratios differ within and among trophic levels, and to examine how stoichiometric imbalances affect fundamental ecosystem processes (e.g., nutrient cycling and spiraling, consumer growth dynamics, and responses to environmental disturbance) in benthic systems.