An endangered species is a type of species in which this type of organism has decreasing numbers and are dangerously close to going extinct. Invasive species are species in which an organism invades an environment where it is not native to, and take over the ecosystem. Local species are species in which the organism is native to that environment and plays a key role in that ecosystem. A keystone species is a species in which the organism is a key part of that ecosystem to thrive; without it, the ecosystem would collapse