Global stability in chemostat-type plankton models with delayed nutrient recycling


Xue-zhong He and Shigui Ruan


Research Report 96-8
Date: February 1996


In this paper, we consider chemostat-type plankton models in which plankton feeds on a limiting nutrient and the nutrient is supplied at a constant rate and is partially recycled after the death of plankton by bacterial decomposition. We use a distributed delay to describe nutrient recycling and a discrete delay to model the planktonic growth response to nutrient uptake. When one or both delays occur, by constructing Liapunov functionals, we obtain some sufficient conditions for the global stability of the positive equilibrium, which can be regarded as estimates of the delays for persistence of global stability.

Key phrases

plankton models. nutrient recycling. time delay. Liapunov functionals. global stability.

AMS Subject Classification (1991)

Primary: 34D05, 34C25, 34K20, 92A1


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