In chapters six and seven of Rambunctious Garden, Marris expresses her thoughts on invasive species. Many environmentalists perceive invasive species as harmful and dangerous to the environment such as, “In 1999 Bill Clinton signed an executive order declaring war against invasive species, defined as “alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.”” And as written in the book, the current conception of invasive species is, “they out compete and eat up complex native systems, replacing them with few dull weeds.”Through these two chapters, Marris aims to reject those beliefs and prove that invasive species can beneficial to nature.
Marris included, “In 1998 a scientific paper declared alien species to be the second gravest threat to vulnerable U.S. flora and fauna, after habitat destruction.” This just shows how highly people held the threat level of invasive species. However, this is only taking into account the negative aspects of invasive species. A research named Dov Sax reported the advantages of invasive species in 2002. He reported that Easter Island, which once had 50 native species, now has a greater diversity of species present on the island. Although seven species have gone extinct after the arrival of alien species, the total number of species has increased to 111. The advantages clearly outweigh the disadvantages. Another scientist named Mark Davis also disagreed with the fact that alien species will immediately compete with native species. They will sometimes help the native species flourish better than before. He uses the example of the Pyura praeputialis, which is “a squidgy brown sea-squirt-like creature from Australia.” This creature increased biodiversity on Chilean rocky tidal shores, creating a landscape for invertebrates and algae. Invasive species are also known to save the native species inhabiting the area. In Rodrigues Island, the songbirds and the fruit bats were almost close to extinction until the invasive species overtook the area, and “almost by accident” saved the species from extinction. Marris uses chapter six to convince the readers that invasive species are not completely harmful, and that they can be beneficial.
In chapter seven, Marris talks about her idea of a novel ecosystem. A novel ecosystem should not be compared with an ecosystem similar to that of a baseline. A novel ecosystem has been touched and altered by humans, but is left alone afterwards to thrive and change on its own. Contrary to what scientists believe, the novel ecosystem can be an area of greater diversity than those environments which have not been touched. With the prospective hybrids in place, as well as the native and invasive species, there is no limit for growth.
Through these two chapters, I can say that I was convinced in believing that invasive species are indeed helpful to our ecosystem, to an extent. Such as the example given before, if the benefits outweigh the harms, I feel that invasive species should not be exterminated or completely be unwanted. Invasive species offer more than just biodiversity, as they can help the environment grow and advance, as well as save our endangered species. I believe the scientists and environmentalists should gain a stronger interest in these invasive species and provide methods of supporting them.
