Effect Of Random Noise On Grassland Ecosystem

In real life,vegetation ecosystem is affected by human activities and serious degradation,led to the destruction of ecological balance,the deterioration of climate and a series of problems,which directly threatens human life and property security.In order to describe the stability of the grassland ecosystem truly and intuitively,this paper uses stochastic dynamics theory,based on the ecological system possessing typical significance Shnerb vegetation dynamic model and proposed by Ceng Qing cun et al in grassland ecosystem dynamics model,establishing the corresponding stochastic dynamic model,the main work is as follows:(1)We take advantages of FPK method and add some disturbances to study the impact of noise for the model of grassland ecological system.The result shows that after the introduction of random noise,the stability of the grassland ecosystem changes,and in a certain intensity of noise will make the system steady state transformation,so that the bifurcation point of the model changes.(2)For the simplified grassland ecosystem,we firstly set up a stochastic model and use stochastic Runge-Kutta scheme to simulate the grassland ecological dynamics.The result of our study demonstrated in the bifurcation interval,the random noise of the noise intensity is large enough to make the system stable,and the bifurcation value of the system is changed.Through the research analysis,control system parameters and noise intensity can make the ecological system steady changed.