In this Spot on Science, Dr. Emily Rauschert, Assistant Professor of Plant Ecology at Cleveland State University, explains the qualities of invasive plants and how they are harmful to other plants, ecosystems, humans, and the economy. She also shares samples of bush honeysuckle, phragmites (common reed), English ivy, and giant hogweed!
Class Discussion Questions:
1) How can you prevent the spread of invasive plant species?
2) Why are invasive plant species so detrimental to an ecosystem?
Read the Script:
You're being overtaken by green invaders. No, not aliens from outer space. I'm talking about plants from other states, and even other countries. You've probably heard of invasive species of animals that arrive here and impact the local environment, but have you ever heard of invasive plants? Well, I invited Dr. Emily Rauschert over to explain. She's an assistant professor of plant ecology at Cleveland State University. I started by asking her, what is an invasive plant?
- An invasive plant has to have two important qualities: One is that it's not from here, So, it's not from Ohio, or it's not from North America. But, there are a lot of plants like that, that we really value, like a lot of our crops are also not originally from Ohio. So, to be considered an invasive, it also has to be causing harm, in some way. So, it might impact human health in a negative way, it might lower the diversity of other plants, because it competes with plants, it could also cause economic damage, so we have to pay a lot of money to get rid of it, or to fix problems that it creates. And sometimes, they change the way ecosystems work, as well.
- [Host] So, tell me a little bit about some of the invasive species that you brought in for us to see today. What's this first one in the front, with these pretty berries?
- So, this first one in the front with the berries is bush honeysuckle, which is an invasive shrub, And, unfortunately, once you have it, it gets spread by birds, who love to come and eat the little red berries. So, it's difficult to get rid of it, once you have a lot of it, because the birds will keep spreading it. Another plant that I brought, this is the commmon reed, which is also called phragmites, and this one is of a special concern because it can grow so densely, that no native plants can grow with it. And, it can take over large, wet areas, and really just become the only plant you see there, which can be harmful for the wildlife, as well. And so, there's a lot of big projects to try and get rid of some of it, so that native plants can come back.
- [Host] And another one, this one, on the end, I recognized this when I saw it. It's your simple English ivy. I didn't realize this was an invasive species. I see this in everyone's yard!
- [Emily] This is a really common species for people to plant for ground cover. And, unfortunately, if it just stayed in your yard, it wouldn't be so bad, but it can spread into forests, a little bit, and then native plants have a hard time growing through because there's so much ivy, growing very densely. And so, English ivy is one of the plants that is also not native, and it's causing trouble for some native species.
- So, some of that harm that we've talked about with these is it makes a lot of competition for other plants--
- [Emily] That's right.
- And that it can be really hard to get rid of. And you said that there's another one that, thank you for not bringing it in, what is it called?
- Giant hogweed.
- [Host] And what does giant hogweed do? It's an invasive plant.
- So, giant hogweed is a phototoxic plant, meaning it has toxic effects in the light. So, if you get the sap on your skin, and then you're in the sun just a little bit, you can get a really bad burn from the sun. So, that's one of the ones I didn't wanna bring, because I don't want any of us to have that problem. But, it is a human health impact species, so we work very hard to get rid of it when we see it.
- [Host] Right, that's like a reverse sunscreen.
- That's exactly right. It's just like reverse sunscreen.
- And so, what can we do to, kind of, stop invasive plants from growing?
- So, the first thing is to not plant invasive plants, if you can avoid it. There's a lot of great native nurseries and the best way is to not have them here in the first place. If you already have them, maybe in your yard, and you wanna get rid of them, you could try pulling them out, or digging them out. We call that "mechanical control". That works if there's a little bit, but sometimes that's a lot of effort. You can use herbicides to get rid of some invasive plants, and that works better if it's a bigger area that has a problem. We also sometimes have biological control, where scientists have found insects, or sometimes it's a fungus, that will, hopefully, attack just the invasive plant, and nothing else, as a way to deal with a problem that's on a larger scale. But you have to be careful with biological control, that it really just impacts the invasive, and it doesn't hurt any of our native plants or our crop plants.
- [Host] So, first step is just don't plant any English ivy in my garden.
- That's right. And if you have some in your garden, you might wanna think long-term, and slowly remove some of it, and there are a lot of native alternatives that you could plant in your yard, instead of invasives.
- Great! Well, thank you so much for coming in.
- Thank you!
- It's been great.
- Thanks for inviting me!