What are ecologists supposed to do about invasive species? In Chapter 6 of Rambunctious Garden, Emma Marris discusses the possibilities. In Chapter 7, the concept of a Novel Ecosystem is discussed and there have been some arguments as to what that is. We will see the problems and potential solutions of both invasive species and novel ecosystems.
Invasive species are just what they sound like, an unwanted plant or animal that is accidentally introduced to an ecosystem, and thrives. The species overtakes the native population and many times destroys a beloved species. An example of this would be feral cats in New Zealand. Marris points out that the cats wiped out the native wren. Another example would be the brown tree snake in Guam. The snakes also killed birds. These birds were pollinators that distributed fruit tree seeds. What solutions do scientists have in mind?
One solution is physically removing invasive species by using strike teams. Unfortunately, strike teams are very ineffective. Within a few years the “exterminated” species becomes invasive again. Top ecologists like Shahid Naeem of Columbia University, “would love to get rid of every invasive species on the planet and put all native species back in their place.” This agrees with the idea of a novel ecosystem. An ecologist like Naeem would think that a novel ecosystem is one dominated by native species.
Ecologist Mascaro holds an alternative view of novel ecosystems. He believes that an ecosystem shared in dominance by native and exotic species is what makes it thrive. He looks at the services being provided by the exotics such as filtering water, controlling erosion, and building soil. A native ecosystem does not necessarily have these things. Mascaro describes his favorite ecosystem, the mango forest. The forest is filled with life in every crevice. There is strawberry guava (considered invasive), rose apples, the Queensland maple, and candlenut. All of these invasive species are living together in harmony. Many traditional ecologists will disregard this area because it is filled with invasive species. They are living in a quite healthy ecosystem, though.
It is things like this that make me question an ecologist’s agenda. In politics, there are liberals and conservatives. I did not know that was the case in ecology. There are a new class of liberals, like Mascaro, who are trying to stick up for these invasive species by saying that ultimately they are good for the ecosystem. Other ecologists like Naeem are saying that the old baseline method that ecologists have relied on for decades is the way to go. It is just a political debate within science in my opinion.
What is an invasive species? Is it merely something that was not there when the Europeans arrived? But what if that species is actually good for the environment, like the strawberry guava for the Hawaiians. Marris states that invasive species are only really overpopulated for the initial few years, the environment controls them eventually, like the zebra mussel, which became food for the ducks on Lake Erie. Maybe a novel ecosystem could have invasive species, but it remains to be seen if ecologists can live with that.
-Chandrapaul
