Although species diversity is one of the cornerstones of ecosystem stability, importance and richness, some plant and animal species are undesirable in the landscape. These are alien species, some of which are even invasive species, and they gradually displace native species and reduce species diversity. In the Esplanade wetland, it is an ashleaf maple, which can displace almost all other species and the American mink, which mainly threatens water birds and fish resources. Maybe you have noticed another unwanted guest here?