Modelling the dynamics of wetland macrophytes: Keoladeo National Park wetland, India

Mathematical model studies have been conducted to investigate the effect of excessive growth of wild grasses such as Paspalum distichum on the growth of other macrophytes in the wetland of the Keoladeo National Park, Bharatpur, India. The model parameters are determined by the regression analysis of the observed biomass data for the Paspalum distichum and other aquatic macrophytes. A good agreement of numerical solutions with the observed data shows the applicability of the model. The model results show fast growth or the Paspalum distichum to its carrying capacity and decay of other macrophytes to a low equilibrium density thus demanding proper management of the wetland. A non-linear stability analysis of the control model incorporating the effort of removal of the grasses establishes the unconditional stability of the model solutions. Applying the model to the Parkʹs wetland, it is found that an increasing effort is required to control the wild grasses. It is also seen that an increased rate of depletion of the grasses not only reduces their equilibrium and peak densities but also helps in restoring other macrophytes to the initial state.