Invasive Species and the Threats They Pose to Biodiversity (by Juniper Jenkins)


treewillametteVolunteering for Metro’s Native Plant Center opened my eyes to the importance of protecting ecosystems through the reduction of invasive species and the protection of native ones. The work I did was seed collecting, so my job was to gather and store the seeds of various native plants so that they could then be distributed and planted. Many of the seeds I collected came from rare and endangered plants that we were hoping to revitalize. I learned that increasing the abundance of native species and reducing the invasive species helps promote biodiversity, which is crucial to a healthy ecosystem. Without a healthy diversity of species, an ecosystem is less capable of supporting life, and species die off. After my volunteering experience I decided I wanted to do some more research on invasive species and the dangers they pose to biodiversity. The question I developed to guide my research was, ‘how do invasive species threaten ecosystems and what actions can we take to reduce them?’ After acquiring a better understanding of how invasive species threaten eco-systems, I decided to focus on local ecosystems near the Portland area and what can be done to protect them. I discovered that the prairies in the Willamette valley are currently at risk due to invasive species and diminishing biodiversity. I hope that my public writing on this topic will raise awareness about this risk and provide some information on what can be done to support this precious ecosystem.

Research Collection:

Clout, M. N., and C. R. Veitch. “Turning the tide of biological invasion: the potential for eradicating invasive species.” Turning the tide: the eradication of invasive species. IUCN SSC Invasive Species Specialist Group, Gland, Switzerland and Cambridge, UK (2002): 1-3.

This article discusses the dangers invasive species pose to biodiversity and the importance of taking action to keep invasive species under control before it is too late. The article stresses that invasive species are one of the main causes of native species extinction, and the extinction of native species causes severe ecological damage. It also claims that our first priority should be to prevent new species from invading and our second priority should be to eradicate existing invasive species. This source gave me a better understanding of the ways in which invasive species cause harm and what the best ways to reduce them are.

Simberloff, Daniel, et al. “Impacts of biological invasions: what’s what and the way forward.” Trends in Ecology & Evolution 28.1 (2013): 58-66.

This article introduces and explains the new field of study called invasion science, which involves detecting, understanding, and mitigating the impacts of invasive species. It talks about the difference between harmful and useful invasions and how to distinguish them. The article claims that all effects including ecological, economical, and sociological must be examined in order to determine whether or not an invasive species is actually harmful. It also includes a table of specific invasive species and their affects on ecosystems.

Clark, Deborah L., and Mark V. Wilson. “Fire, mowing, and hand-removal of woody species in restoring a native wetland prairie in the Willamette Valley of Oregon.” Wetlands 21.1 (2001): 135-144.

This is a study conducted to determine the best methods for reducing invasive woody species and promoting the growth of native plants in the wetland prairie of the Willamette Valley. The methods observed include burning, mowing and hand removal. The study concluded that burning and hand removals were most affective for removing woody species and other invaders and increasing certain native herbaceous species including the Lotus purshiana and the Veronica scutellata. However, burning also reduced the flowering of the native wetland grass. According to the study, the method that did not have any positive affects was mowing with removal of cut materials. This source was very beneficial because it increased my understanding of the specific species that threaten the local Willamette valley ecosystems and what the most beneficial procedures for reducing them are. It also provided some background information about the Willamette valley and the causes and effects of the growing invasive species population.


Public Writing:

In this era of concern about pollution, habitat destruction, and growing numbers of endangered species, you would think all wild life is worth protecting, right? Wrong. Certain species of plants and animals known as invasive species are actually one of the leading causes of diminishing biodiversity and species extinction. Invasive species are species of wildlife that are not native to the ecosystem they inhabit and cause harm to it usually by overpowering the native wildlife and diminishing biodiversity. Invasive species are a growing threat to ecosystems across the globe due to several factors including climate change and purposeful or accidental transportation of wildlife by humans or animals. Unfortunately, many people undermine the severity of the problem and do not realize how detrimental invasive species are to the environment.

In fact, it wasn’t until a few weeks ago volunteering for Metro’s Native Plant Center that I began to develop a thorough appreciation of the damage they cause. As a seed collector, it was my job to gather and store the seeds of various native plants, many of which are rare and endangered. These seeds were then to be distributed and planted in various locations in an effort to improve their chances of survival. The volunteer coordinator on site explained to us that it was very important to support the native plants so that the invasive ones wouldn’t completely take over. She pointed out several invasive weeds that seemed to be growing everywhere and instructed us to pull as many as we could. This sparked my curiosity about what constitutes an invasive species and how they manage to cause so much damage. I decided to conduct some more in depth research on the topic and then share my discoveries to raise awareness of this global concern and hopefully inspire some people to take action.

I would first like to mention the startling fact that second only to land conversion, invasive species are the biggest threat to biodiversity in ecosystems. Not only can they alter the food web and the chemical makeup of their environment, they compete with native species and usually win because they reproduce quickly and have few or no predators. As native species die off and invasive ones persist, biodiversity decreases and many species go extinct. Extinctions are dangerous because they throw off the very delicate balance of an ecosystem and have a domino affect leading to more and more extinctions and less and less biodiversity. Every species on Earth including humans depend on the natural resources biodiversity provides; so in short, invasive species are a very serious threat. Every ecosystem in danger of being taken over by an invasive species is also a danger to the planet as a whole.

To use a local example, the Willamette valley is a collection of ecosystem currently at risk due to a growing number of invasive species. Originally, the Willamette valley was mostly made up of prairies that were home to many native herbaceous plants and animals. Prairies are ecosystems made up of flat and open grasslands with little to no woody plants (trees and shrubs.) These prairies were maintained by the Native Americans who lived in the Willamette Valley and periodically burned the land to promote the growth of food plants. Unfortunately, with agricultural and urban development, most of the prairies are gone, and those that remain are being invaded by woody plants. As these invaders take over, many species become endangered or extinct. Species at risk include the Lotus purshiana and the Veronica scutellata both of which are native herbaceous species or grasses that are native to the prairie. Examples of invasive species include English ivy or Hedera helix and Scot’s broom or Cytisus scoparius. Research has shown that generally the best way to reduce invasive species in the Willamette prairie is by burning or manually pulling. Unfortunately this is a time consuming and laborious process. That’s why we need all the helping hands we can get!

 Supporting global biodiversity begins with supporting the biodiversity of local ecosystems in your community. We need to start taking more action against this growing problem whether through volunteering, speaking up in our communities, or donating to influential organizations. The Nature Conservancy is a great organization to donate to or volunteer for, and they do a lot of work for the ecosystems of the Willamette valley. Portland Metro is also a great organization to volunteer for. I can say from experience that volunteering can actually feel more like play than work. You get to meet new people, spend time in beautiful natural areas, and most importantly feel good that you are benefitting the world. Getting out in the world and volunteering not only gives you a better understanding of how ecosystems work, it also makes you appreciate the beauty of them and motivates you to want to do everything you can to support them. Every eco-system we save from the devastation of invasive species is one step toward a healthier Earth. So get out there and lend a helping hand.



One comment

  1. Itay Lerner

    Juniper, I really enjoyed reading about your volunteer experience! I never would have thought that invasive species are such a big threat to our ecosystem, and it is really interesting to get to know how we are being affected by that in our own community. Also, thanks for leaving down different names of organizations that are really making an effort to make a change, that’s great!
    Your writing was very smooth and informative! I feel like I learned a lot about why it is important to preserve native plants and how we should go about doing so. The introduction had helpful background information that made the public writing much easier to understand as well. If I had any advice I would say try to be a little more concise. You seemed to be repeating yourself every once in a while so look for things to cut out of your writing that way every sentence is necessary and helpful. All around you did a really great job, thanks for sharing and I wish you the best of luck if you continue to help this cause!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: