Written by Elizabeth Pepper, ESLLC 2017-2018
The Growing Issue of Invasive Species
Did you ever read the book “The Lorax” by Dr. Seuss? I remember reading this book as a kid and being completely fascinated by “Those trees! Those Truffula trees!” (Dr. Seuss). But did you ever think about how Dr. Seuss was presenting environmental issues throughout this fictional narrative?
There are several different environmental issues that Dr.Seuss brings up throughout this book, but the idea of people being an invasive specie is something that many people might not consider. An invasive species is an organism that is not native to a specific area which has the tendency to spread to a point that is believed to cause damage to the environment. Think about it; the Once-ler comes in and chops all the trees down leaving a barren land and a polluted place where the entire environment around is destroyed. Well, unfortunately, this issue of invasive species is not just a fictional creation and humans are not the only invasive specie responsible for causing damage to the environment.
The issue that arises within the article “Going home again” in High Country News, is the issue of an invasive species called ravennagrass. The article describes,“The bushy plant, sometimes called elephant grass, grows up to 14 feet tall, in bunches nearly half as wide. It was introduced as a decorative landscaping plant in Ohio in the 20th century, and by 2001 had reached the Southwest. While its beauty and resilience make it a popular accent amid rock gardens and succulents, ravennagrass can push out native plants, like white sagebrush” (Paige Blankenbuehler). With the introduction of invasive species in this harsh desert climate, organisms that depend on native species are negatively impacted by the introduction of invasive species. With the increase in climate change, it become harder for native species to compete with invasive species that have a higher tolerances to changing conditions such as a dryer climate.
The way that Jackson tried to combat the issue of the invasive species was by killing or removing the ravennagrass, but when Jackson returned, the efforts failed and ravennagrass still covered areas where the invasive species had been removed. Ravennagrass is not the only invasive specie that raises issues for ecosystems. Other invasive species of plant and organisms continue to negatively impact ecosystems around the world. Invasive species pose a threat to the biodiversity of ecosystems by reducing species richness and evenness through outcompeting native species. Species richness is the amount of different species in a set area whereas species evenness is the population size of each species. As biodiversity of an area decreases, the ecosystem becomes unsustainable.
Many times invasive species are introduced to areas for their aesthetics or to fix issues of population size through the introduction of a new species. For example, in Yellowstone wolves were reintroduced into the ecosystem to control the population of elk in the area, but with no natural predators of wolves in the area, wolves began to overpopulate and cause an issue as being an invasive species. Currently, as wolf populations decrease in Yellowstone, the elk population is rising to a more stable population. Other invasive species include Zebra Mussel, Silver Carp (see below), and in Colorado, Yellow Toadflax.
In widespread areas where invasive species prevail, especially with invasive plants, eradication of the invasive species is hard to attain. Prevention is the best method in reducing the spread of invasive species. So next time you decide to garden take some time to consider if the plant you are planting is native or not.