What is an invasive plant?
An invasive plant is one which not indigenous to the region. These plants are transplanted from a location where they are often harmless to new locations. In these new locations the other plants, insects, climate, and animal life that kept them from propagating too quickly are not present. This makes it easy for the plant to grow unchecked and to damage the local environment.
How do invasive plants affect the local ecosystem?
The invasive plants usually have the advantage of not having anything in the new ecosystem that can slow its growth. Because of that the introduced species grows rapidly and uses the resources that had previously been used by native species. With limited access to resources such as sun, water, or soil the native plants may begin to die. With the death of these native plants the ecosystem is altered. Animals, birds, and insects that once relied on these native plants now have to look elsewhere for their food source if the invasive species is not suitable.
One of the most prominent examples of an invasive plant drastically altering an ecosystem is kudzu. This plant is native to regions in Japan and Asia and was introduced to the United States in the 1870s. It was intended to be used for foraging and as an ornamental climbing vine. In the mid 1900s it was planted widely in the south east to prevent soil erosion as it was found to be an extremely fast growing ground covering. As with many invasive species the introduction of the plant seemed not only harmless but beneficial. Kudzu can be used to make foods, medicines, and in agricultural pursuits when it is properly maintained.
Unfortunately the environment in the south east allows the plant to reproduce almost unceasingly. The warm wet weather with few hard freezes allows the plant to grow almost year round. It has made farm land and grazing land useless and the weed, as it is now classified, itself is very difficult to remove. As it grows it has destroyed millions of dollars of crops, invaded farmland, and damaged numerous buildings.
By looking at kudzu as an example, it is easy to see why it is so important to restrict the introduction of invasive species into new environments.