Invader species refer to any kind of living organisms that are harmful to the ecosystem (SITE). In Washington Marlatt Memorial Park, the invasive species are usually vegetation (exotic or native) that tend to outcompete the native species (Keane, 2015). The exotic invasive species are mostly introduced in a native ecosystem by accident. In this case, the introduction of exotic species does not include the environmental resistance of the species, such as animal consumption (Keane, 2015). Thus, the exotic species are biotic potential which means they have the ability to increase productivity due to the absence of environmental resistance (Keane, 2015). In Washington Marlatt Memorial Park, the Sericea Lespedeza (Lespedeza cuneata) is an exotic