Flora and Fauna of Discovery Park: Site 2: Invasive Plant Species

While many people go to urban or national parks to observe and be part of native habitat, few realize how many invasive species there are. If you are unfamiliar with a system, it is hard to pick out what is out of place. Of course, most of us grew up with invasive plants, so it doesn’t seem so odd. In fact, many of us probably grew up with parents who took pride in growing exotic plants in their backyard. Unfortunately, it is typically these plants that escape the backyard to invade native habitat. Also unfortunately, we select species that have long flowering and fruiting times, grow quickly, produce sweet fruit, and have beautiful flowers. This makes pollinators select these plants over other native plants, and the sweet fruit is enticing to animals like birds, which then disperse the seed over long distances. At this site, we have a couple examples of this. First, and most commonly, is Himalayan Blackberry, characterized by the sweet black drupes, green photosynthetic stems, many stamens in the white flower, and thorns. This was initially planted because the fruit was tasty. Almost right next to it, we have Scotchbroom, which is characterized by its brilliant yellow flag flowers which are bilaterally symmetric. A single bush can produce hundreds of seeds, which are often quite resilient. Furthermore, Scotchbroom is a nitrogen fixer, which alters the soil so that it can take advantage of the altered chemical properties. This allows it to outcomplete native vegetation and makes it very difficult to eradicate. These are but only a few of the invasive species that we’ll observe, and hopefully as we point out more, you’ll see how much of “nature” really is a slow motion invasion of alien plants.