An analysis of the interactions between pelagic food web processes and element cycling in lakes. While some findings are examined in terms of classical concepts from the ecological theory of predator-prey systems, special emphasis is placed on exploring how stoichiometric relationships between primary producers and herbivores influence the stability and persistence of planktonic food webs. The author develops simple dynamic models of the cycling of mineral nutrients through plankton algae and grazers, and then goes on to explore them both analytically and numerically. The results thus obtained are of great interest to both theoretical and experimental ecologists. Moreover, the models themselves are of immense practical use in the area of lake management.

1 The Eutrophication Problem in Temperate Lakes: Practical Aspects and Theoretical Ramifications.- 2 The Biogeochemical Theatre - Phosphorus Cycling and Phosphorus Household in Lakes.- 3 Algae and Nutrients: Uptake and Utilization of Limiting Nutrients in Generalized Phytoplankton Species.- 4 Herbivores and Algae: Food Utilization, Growth and Reproduction in Generalist Filter Feeders.- 5 Nutrients, Algae and Herbivores - the Paradox of Enrichment Revisited.- 6 Approaching Planktonic Food Webs: Competition, Coexistence, and Chaos.- 7 Grazers as Sources and Sinks for Nutrients: Conclusions, Limitations, and Speculations.- 8 References.- A Appendices.