PERIODIC OSCILLATIONS IN A SPATIALLY EXPLICIT MODEL WITH DELAY EFFECT FOR VEGETATION DYNAMICS IN FRESHWATER MARSHES

Abstract

Time delay is incorporated into a spatially explicit model for vegetation dynamics in freshwater marshes and the effect of the delay is investigated by using qualitative analysis and numerical simulation. If the specific rate of plant senescence is sufficient small then spatial homogeneity will be induced eventually for any delay, while if it is large, then a switches may occurs as time delay increases and there is a periodic oscillations if it exceed a critical value. Thus, delay time in ecosystem may be one of the important factors to induce temporal fluctuation in nature.