A robustness analysis of biological population models with protection zone

Establishing protection zone has been widely used to preserve endangered species. We study the effect of protection zone in random environment by a stochastic model. Our results show that the establishment of nature reserves can protect endangered species effectively in good conditions. Under very bad conditions, though protection zone cannot protect species from extinction, it also can slow down the speed of extinction. Based on our results, we give some methods to strengthen the effect of protection zone and provide a method of dividing the protection zone. In addition, we introduce some examples and use several numerical simulations to enhance our main results.