Application of the CNOP Method in the Shallow Lake Ecosystem

It is serious on the degradation of the shallow lake ecosystem at present, while the recovery of the macrophytes vegetations and the increase in water transparency have been the main contents of the ecological restoration. Using a two-variable model, we discuss the instability and sensitivity of the ecosystem to the finite-amplitude perturbations related to the initial condition with CNOP-I method. Results show that the linearly stable clear (turbid) water states can be nonlinearly unstable with the finite-amplitude perturbations. The results also demonstrate that the facilitation interactions between the submerged macrophytes and the water transparency are the main trigger for a shift from the turbid to the clear state.