Ecologists are very often opposed to a new species entering an environment. They believe that the new species will only destroy the original ecosystem and become an invasive species. A common story that many ecologists tell about the effects of an invasive species, Marris relates, is how “a species invades, and the ecosystem collapses, species go extinct, and complexity and diversity are replaced with a monotonous and weedy landscape dominated by invaders” (97). Marris argues that this is not always the case and discusses the idea of a “novel ecosystem,” one that represents “the future of our planet” (122). I agree with Marris that these ecosystems should be studied since they are dominant in the world and they are not as harmful as many ecologists believe them to be.
Though many ecologists do not believe that exotic species would ever be able to help increase diversity, often exotic species can actually end up helping the ecosystem and allowing the other species to continue to survive. Marris points out once again that humans have introducing new species to areas for many centuries. While sometimes the new species can bring about a lot of harm like diseases they can carry with them or if they become predators and eat an entire population of native species, “extinctions that are directly attributable to introduced species are quite rare” (104). Though such damage is very rare, “these emerging, exotic-dominated ecosystems still look like trash to most ecologists,” Marris writes, “but a brave few have embraced them and given them a more positive name: novel ecosystems” (109).
Marris defines a novel ecosystem as ones where there was “anthropogenic change” at one point but are currently not under management by humans (114). This applies to most ecosystems in nature because they almost all have been affected by humans in some way. In a novel ecosystem, new species may be introduced into the area, something that ecologists fear due to the risk of the new species becoming invasive and “ruining” the ecosystem. In some cases, novel ecosystems can cause “homogenization and extinction” but they can also foster “increased diversity and brand new species” (122). For example, in Puerto Rico, the exotic -dominated ecosystem actually was “functioning better than nearby native forest” (113). Novel ecosystems are often very beneficial. They can can provide a habitat for the native species if their habitat is gone and they can sometimes even help restore the native species. Rather than a decrease in diversity, as ecologists assume will happen in a novel ecosystem, diversity may instead be on the rise. One hypothesis for the increased diversity is that the exotic or introduced species may initially run rampant but will eventually calm down due a built up resistance by the surrounding species. Thus the new species may become integrated into the ecosystem and form the potentially diverse novel ecosystem. Ecologists need to stop trying to keep nature in a static position and embrace studying the many new forms of nature that evolves.
