“Impact of Invasive Japanese Barberry Cascades Through Local Food Webs”
Impact of Invasive Japanese Barberry Cascades Through Local Food Webs
This article by Ed Ricciuti highlights the invasion of the Japanese Barberry in the Eastern and Midwestern United States and its impact on the food web of the local wildlife. Since the intrusion of this plant which covers forests, spiders and ants have been most affected and have seen a large decrease. This decrease could be due to multiple things, including the Japanese Barberry affecting the leaves and the soil, or even interactions between this plant and herbivores. The decrease in the number of ants and spiders causes a “bottom up” cascade in the food web. Now, birds who would usually eat these arthropods will struggle to eat, causing a decrease, and so on up the food web.
The balance of a network such as a food web is extremely important in ensuring the balance of an ecosystem. Due to this decrease in spiders and ants, the food web is out of balance and the effect will cascade throughout the network. This is known as the term: “cascading extinctions” on page 38 of the textbook: Networks, Crowds, and Markets. A food web network consists of species as the nodes and a directed edge as “who eats who.” Due to the overlap of species eating other species and so on, the network can become very complex very quickly. The impact of the Japanese Barberry causes nodes and edges to disappear, due to decrease in ants and spiders and the bigger cascade which in the end causes the network to go from very complex to very simple.
The importance of understanding the network of this food web directly relates to the biodiversity of an ecosystem. Sadly, as the networks become less complex, so does the biodiversity.