Hi, everybody. Welcome to the podcast for discussion to an IBD on invasive species. My name is Amy Sullivan. I’m a visiting assistant professor here at dragonfly and an instructor for IBD. And I am joined today by Kevin Matteson, who’s the associate director for master’s programs here at Project dragonfly. And Judy Metcalf, who is an instructor with Project dragonfly for IBD. And so guys, if you would give a quick intro about yourselves and I’ve asked everybody to share a an experience they’ve had with invasive species.
this is Kevin. Um, let’s see invasive species. I guess. I live in yellow springs, Ohio. So there’s and but I’m originally from New York City. So I was kind of amazed that people’s anger And at this plant notice honeysuckle, that is in the Midwest here, because I had really not heard much about honeysuckle and the East Coast. I think it is around there somewhere. But here in Ohio, it’s just, you know, everywhere along so roadsides and understory and has all these effects that people are very concerned about. And there’s a lot of efforts to remove it and the difficulties in removing it. So yeah, now I kind of just see it everywhere. And nothing specific with it in terms of an experience, but just that it’s sort of ubiquitous and everywhere around.
yeah, uh, so I am actually a professional assistant professor down here in Texas, Corpus Christi, Texas, and my experience With invasives is actually my entire dissertation was based on an invasive species. I did work in Kentucky looking at the effect of Japanese stilt grass. It was actually mentioned in one of the papers that we read this for this discussion, very briefly. And I looked at its effect on insects and spider communities in the temperate forests there and it is, it’s an interesting little grass. For sure. It’s, it’s becoming more and more prevalent in the States, and it causes quite a few issues.
That’s really interesting. Didn’t we had
such an expert on invasive species with us today? So thank you, I think
myself as an expert.
Okay, so my experience. I grew up in the West and I worked really until I started my PhD I lived in the West. And one summer I worked actually several summers, I worked on an army base in the West desert of Utah, and so many invasive species because it’s a highly disturbed ecosystem. And it’s an arid ecosystem that just, you know, it gets torn up by the army regularly. But the invasive species I was thinking about is tumbleweed which is known as its more common name among scientists as as a common name is Russian thistle or cell sola America. It actually didn’t get to the United States until 1873. Although we all have these like, ideas from western movies of you know, tumbleweeds blowing across in the wind. But the thing about tumbleweeds that you don’t realize from those westerns is they’re actually incredibly sharp. What they that they have like spikes all over them and so They build up in like ravines and along fence rows and for some of the survey work we had to do, we had to go down through those ravines and I just remember those tumbleweeds just chewing up my skin and being really miserable to work through. But then the other fun thing about tumbleweeds is so the the rolling motion that they do is its seed dispersal mechanism. But it also causes huge problems in fire season because not only are they really flammable once they dry up and start rolling around. They also catch in the wind and they catch fire like when there’s a fire and they catch fire, the wind will catch them and carry them quite a distance so it makes makes fire season really exciting. So
it’s super cool to think about I love tumbleweed. I love it. I love the adaptations you’re talking about that it has that are just so unique, which is like definitely one of the elements of some of these invasive species like they have the capability to colonize, and and do well in a way that sometimes natives do not necessarily have. And now it seems like like an exceptional example of that.
Awesome. All right. So we wanted to kind of dive into this whole idea of invasive species starting out with both of the artists are a couple of the articles shared the definition of an invasive species from the
from a an executive order by President Clinton. Do one of you have that in front of you? Uh, yeah, I was just
looking for that. I thought I made a note of what page that was on, hang on.
I think it’s is it essentially saying it’s it’s a species that is an invasive species is one that’s also detrimental to so it’s it’s introduced and it’s it’s detrimental is that?
Yeah, that’s that’s the crux of it is that it has to invade and set up a habitat
have a detrimental effects on the system.
And so the language from the
from Meyerson and Mooney says it’s an alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.
Yeah. And that’s, that’s the clinton definition.
And I think it’s, I think that’s really the more common, commonly accepted definition as well. I know you know, from my experience, During research, it was very clear that there was a very clear delineation between non native and invasive. And that that causing harm was the difference.
Right? Which is, which is really interesting because I think so many times people just if they haven’t thought this through, and I’m glad you start, you know, we’re starting with definition. They just think Nani equals bad, you know, across the board. And we know plenty of non native species is that have become common and naturalized in in North America and other areas of the world that actually don’t really seem to be causing much of an impact. I mean, things like dandelion and clover, which are now completely sort of normalized naturalized part of our ecosystem where we’re originally not from here. So yeah, so that’s, that’s interesting that you you experienced that as well. The 90, you know, that you probably had to clarify like, well, this one is, you know, I it’s not native, but it’s not invasive.
Yeah. It’s funny. It’s a conversation I have with a lot of students when they do papers on invasive species, they they tend to use the terms interchangeably. And I have to constantly remind them that just because something isn’t native, doesn’t mean it’s necessarily invasive.
Right. Right. And it is that that piece of it that there has to be harm being caused either economic environmental, or, you know, health. Yeah, absolutely.
Which actually leads right into the biggest issue I had with December love paper.
Okay, let’s hear it,
which is the way that they defined invasive in their paper which is coming from elsewhere. and establishing natural or semi natural habitats, but not necessarily having an impact.
And I think that that
that basically makes it impossible to really define anything
as truly invasive.
It was, it was the one thing I agree with almost everything else they said in that paper, but that was like
you know, it’s interesting because that the paper I mean, Daniel symbol off is this incredibly well known biologist at colleges. He was eo Wilson’s doctoral student, early on at Harvard. And he was looking online, he has 350 publications now. He’s now at the end. of Tennessee. And, you know, he’s one of the few people he can just probably could just write this article you know, based on his experiences and he’s he’s a single author paper here and, and really all you need to do is see his name, Daniel symbol off there at the top of this paper know, he carries so much authority in this field. But I did struggle also to find out to kind of understand and follow his thinking because like, I wasn’t sure exactly what he was arguing in this paper.
Right like, like,
was it that they have that invasive species have more impact than most people think or less impact than most people think?
Yeah, I think because I was the same way as I was reading the paper. I’m like, okay, and I’m not sure what your point is here. When I kept looking for it. There’s got to be a point because this man knows what he’s talking about. I cited him several times myself. Um, but I think that the overall goal was we are. And it goes contrary to his definition of invasive, which I think is where it annoyed me the most. We are limiting the definition of impact by only looking at ecosystem level impacts as nutrient cycling offense.
Yeah, yeah, I picked up on that too. But I think you’re right that the definition is where that gets lost. Yeah. So yeah, I mean, he does point out that for sure, people have been specifically looking at like, nitrogen cycling and things like that. So I did appreciate that he expanded kind of some of the effects that we should be looking for in
you know, in these invasive situations.
Do you want to go into some of those as
well? Yeah, I mean, it was it was really interesting because, you know, the first thing he started off talking about in great deal detail was nutrient cycling. And so yeah. Like, okay, we already we already sort of got that point but, and he listed I mean, there were like 2467 different examples of how invasives impacted nutrient cycling. You know, everything from nitrogen fixers to earthworms, to changes in salinity to you know, water loss with salt cedars in the US Southwest, which is huge, but moved into some things that that are more they made sense to me because I spent a lot of time and a lot of people don’t really think Think about those sorts of things the fire regime changes and how, you know, the the frequency and intensity of the fires. And the changes in the plant community that results from that could be defined as an eco should be defined as an ecosystem level effect, even without the nutrient cycling changes that tend to come along with that. Yeah. The one that actually hit the closest to home for me was the structural changes, because at the end of my dissertation work, I had done this manipulative project where we made we manipulated the biomass of the invasive. And what we didn’t do was come up with a way to determine whether that change in the in the percentage of invasion was the weather that effect was a result of the actual change in the plant. community are a structural change within the plant community. And it was one of the weak points in my, in my experiment in that project. And one of the things that has made publishing it varied. We just didn’t think about the fact that the way that we had set it up we couldn’t distinguish between are there more insects here because there’s more cover? Or are there sex here because there’s more structure. And so it’s a that’s a it’s definitely something that people don’t think about in terms of the changes that happen when you have another non native plant come in and take over and eliminate a lot of the native plants in the in the system.
Yeah, there’s, it’s interesting how
like, I think
symbol office is thinking a lot here about, like the diff the delineations of population ecology versus community. ecology versus ecosystem ecology which I don’t know if many folks in dragonfly necessarily would think about that as much as he is. But basically, within ecology you have like population ecologists who study individual populations and abundance and sort of growth of an individual species. And then you have community colleges to look at species richness and diversity patterns generally are whole communities of species. And then the ecosystem of colleges which look at like all these things like nutrient cycling, and such that he’s talking about here. So he’s kind of saying, I think that the paradigm of many of the early labs that we’re looking at the effect of invasive species was within the ecosystem ecology paradigm and thus focus on the nutrient cycling, and that the structural stuff that you’re getting at UD was sometimes not really looked at and that’s When I guess he starts talking about like beavers and waist, muscles and things that like kind of change the physical structure of environments they don’t. And of course when they do that they also change all these nutrients and water cycles and everything. But that in itself, the structural change is an impact on that. He’s, I think arguing is kind of
an interesting point on that where he was talking about community ecology versus ecosystem or community impacts versus ecosystem impacts. And that he didn’t feel like there needed to be a differentiation between the two. Yeah, it really in reality if you’re studying when you’re studying you either
totally which makes sense but it’s it’s funny how you can we can all get in our own like little black box, you know,
wanting to kind of touch back on the idea that
the Judy was saying that
Of course, when you have changes to when you have changes to fire regime, you’re going to have changes in nutrient cycling, which is pretty clear. And I think it speaks to the idea of trying to break these into specific categories. Because as I look at like cheatgrass is out in the West is huge. This firm is checked on the dimensions under the fire regime change. But you know, when you have a small annual grass replacing shrub land and Juniper woodland, that’s pretty substantial structural changes. And part of my master’s degree, I looked at small mammal communities in areas that had been burned and areas that hadn’t been burned, so burned and taken over by cheap grass versus areas that were still shrub land and not surprisingly, there was greater diversity of small mammals where there was still the shrub land intact, and then you get into all of the control Counting factors like you did with your dissertation. Where was it? Because the resources, aren’t there anymore, you know, the variety of food sources, or is it because of cover? Or is it? You know, I don’t know. But those patterns exist. And I don’t think it’s useful to think about them categorically. But it’s important to realize that there’s a lot of crossover between these these categories that one leads to the other and vice versa.
Yeah, yeah. I
think it’s one of those situations where it’s so hard to parse out the differences and the reality is that almost every
impact that he mentioned,
fluted the statement, it also leads to nutrient cycling differences, but
and of itself, could be considered an ecosystem level impact. Right. So it’s it was it was one of those things, I think that’s where I was spending a lot of time going. Okay, but what’s your point?
everything’s connected, right?
could have done that in fewer than 12 pages
would it? You know, it’s it’s interesting. All these examples like you said he’s he lists like seven or eight examples and I think all three papers kind of that we’re going to talk about like they all give all these examples and they’re super fascinating. I mean, I love reading them. But there’s a point where I’m like, Okay, what is the overall thematic element of this paper besides giving me lots of samples? One of the things I picked up from this one was this, at the end of the symbol off he talks about a conservative, the 10th rule of Williamson and fitter which he says is 1% of all introduced species will become in vasive and for vertebrates in certain areas, Europe and North America, another study found that 25% of introduced species will become invasive. That goes back to what we were saying earlier about, just because it’s not native doesn’t become mean it becomes invasive. Hmm. And but then symbol off goes on to say, Actually, he believes I think this is part of the gist of this article that the true ecosystem, true ecosystem impacts are much more common than it’s normally assume just because they haven’t been studied. They’ve been largely studying terms of this ecosystem lens and not the other structural and community impacts that are likely happening. And then he goes into this, what does he call it the invasive.
It is a sort of invasion, invasion or meltdown.
I don’t know that’s that’s pretty pretty intense language there for sure.
Yeah, so I
I wasn’t sure where he was going and then and then invasion meltdown that certainly he’s written a number of articles on that now and it’s gotten a lot of press coverage. So I’m curious what you guys guys think about that term.
I think his
overall thing is just that like I’m multiple invasive invasive species working together can cause larger in total impacts. So that’s one element of innovational meltdown and then the other is lag time that some of this stuff may be happening more through time.
Yeah, so quote, so the thing with the invasion meltdown, I agree that the language on that was a little bit Like, you know, the sky is falling Chicken Little elves, it’s sort of reminds me a little bit of a trophic cascade. Yep, not that not quite the same. Basically all he’s talking about there is the fact that the these invasive species can be additive their effects can be additive. So introduce dance will cause a problem. If you add introduced two midterms to that, that will increase the population then you have this, this larger problem. He was talking about the Was it the red crab? Yeah, if you think about it here that that coexisted perfectly well with the introduced ants until they introduced the scaling sex. Yeah, and when the insects got introduced, that all of a sudden the ant populations just boomed because there was this additive effect on top of it, and and I think it’s something that maybe doesn’t get taught About enough, from the perspective of people tend to study and invasive. And there’s the facts, as opposed to the effective invasives on this compute community. And it’s well, some of that is just a mechanism. It gets much more complicated when you do that. Yeah. But I think it’s an important thing to mention and to note to pay attention to. I did want to go back into what you were talking about in terms of the of the 10th rule. Because I think I think you’re right in your interpretation that he’s basically saying that not as many of the things that are introduced will become invasive. But the difference between the Williamson fitter rule and the jetski and Strayer was that the rule of 10s, the Williamson and fitter talks about all introduced species first The Jessica and Strayer is talking about vertebrates, between Europe, North America. And so I think that it’s it is an accurate statement to say that fewer of the things that are non native become invasive. But I also think it’s it’s a statement that says, but that also depends on what kind of species you’re talking about, and where they’re where the invaders coming from and going to.
Right. And I don’t know if you guys have read, there’s an author, scientist with the last name sax. sx, who’s written a lot on invasive species in in a number of very interesting articles. But one of them he talks about the idea of saturation, and that it’s assumed in ecology that there’s a finite number of niches, ecological niches for species and that therefore, if invasive or introduced species are taking up some of those it would reason that, like the native species are going to decline. But some of this author Sachs, his work had indicated that saturation, that they were not reaching saturation in certain environments. So you were adding more and more introduced species. And yet native species were still present, we’re still or even, you know, overall richness was increasing. And it was very controversial, because clearly it flies in the face of the notion that introduced species are one of the leading causes of species endangerment.
Well, so here’s here’s an interesting again from from my research, so Japanese stilt grass, has been studied quite a bit, in a lot of different ecosystems and habits. tabs and there is there are mixed results coming from coming from the literature, some of the some of the literature shows no effect at all some of the literature shows a decline in species richness and abundance. Some of it shows a slight increase. And my data actually showed a slight increase in comparison to the other studies that had been done in similar habitats and climates. And so, it was it was kind of It was terrifying, first of all, as a graduate student to come up with data that contradicted all the guys that have been public. You know, what did I do? Um, but it was what was interesting was when you look at the way the studies were designed, it was it was pretty clear that because of the level of our invasion, that the impact hadn’t really hit, yet. This significance of the impact hadn’t really hit because our invasion wasn’t dense enough. Right, or with the artificial invasions, where they were at artificially at 100%. And very clearly seeing declines in abundance and, and diversity of insects in those communities. Because we were actually seeing increases in a few different species.
That’s interesting. So I think, I mean, that speaks to, first the idea of lag time from when something is introduced to it becoming invasive, which you know, not all things that are introduced will become invasive, but the ones that do become invasive, there’s often a lag time between its initial introduction, and becoming invasive, and then a further lag time between like the beginning of invasion and seeing really the effects of that. I think that’s a really interesting point that a lot of the studies that we as No community colleges do.
We are looking at kind of small scale and extreme time.
Yeah. Yeah. Like, you know, what is it going to be if it’s at this point?
Right. Well, and that’s that’s sort of that was sort of my thought with with what we were seeing, which is okay. Right now it actually looks like it’s having a beneficial effects. Mm hmm. But 10 down 10 years down the road. You know, if that was the only time anybody looked at micro CGM, then 10 years down the road, you’re having this negative effect? Because it’s taken over and nobody’s done anything to stop it. Because it seems like a good thing. Yeah.
That’s a really interesting point. But right.
So with that, I was thinking Kevin, as you were talking a little bit ago about kind of the difference between population ecologist approach and ecosystem ecologist approach and all of those things. The article by mayerson and Mooney kind of speaks to that as well. Thinking about how how we look at invasions you have, you know, your ecologist looking at the local level, and maybe the regional level, that maybe we need to think about these things on a more global level.
What were your takeaways from that?
Yeah, I mean, so that article is, I guess I have a few notes here on it in general, but first of all, I just want to share, I always think about where it’s published, like, what journal and who the authors are. So, this author is by Laura Meyerson. She’s at the University of Rhode Island and Harold Mooney, who is the second author visit Stanford University. So it’s a two author paper. And it seems like from the acknowledgments they they state that the idea for this article, this sort of synthesis article originated from an ESA or the cod ecological Society of America meeting, which is, which is a great annual meeting to it’s to attend if anyone’s interested in that all that. And then they basically the ESA has these different journals, including ecology, which is like one of the most highly cited and respected journals in the field. And then they have another journal, which is this one that it’s published is called frontiers in ecology in the environment. Or just frontiers. Most people would just say, just frontiers, but it’s like, more looking like a magazine with sort of glossy images with color, color figures and so forth. And it’s really focused on cutting edge Research is the idea. So just a little bit of bear about this article and where it’s published and the people publishing it. Um, but yeah, overall, it does seem like they, they really talk at one point about the CDC, the Center for Disease Control and how well they’ve done at preventing disease spread. And they kind of by having the mandate, even though CDC is a US Government Center, that it has sort of international reach and tries to stem off disease emerging in different countries, because that’s the best way to prevent it from arriving here. And so they kind of use that as a parallel to we should be doing the same thing with invasive species and looking more at a global and interdisciplinary kind of
role in terms of preventing their spreads. Yeah,
this I love to do it. examples in this paper where they were, I think it was this
is my working.
There were there were a couple of examples in here that that I really liked the North American Plant Protection organization that was talking about the efforts between Canada and the US and Mexico and trying to sort of coordinate and limit the movement of some of these invasive species. And I thought there was another example in here.
There’s the Great Lakes and Baltic
Sea. Mm hmm. Yes, with the with the ballast water and those sorts of things that they were talking about. And, you know, I agreed with a lot of what they said in this paper that you know, this is not something that you can manage on just a local scale. That if you don’t have cooperation from from Other places that you’re not going to get very far in dealing with these issues.
Right. And they they also kind of I’m always a fan of like unique terms. So invasion beachheads you talk about as like the Great Lakes region region in this area. And if you look at there’s, there’s like a figure there where it shows the United States and and has different colors for the percentage of different watersheds that are that have invasive species at a certain level. And basically, when you look at that, it’s like New York, on the East Coast, sort of New York down to Maryland is all black, which is like greater than 25% of the, I guess the total species in those watersheds are invasive. And there is invasive orange, native non native native Okay, so you Yes, For example, getting the terminology right. And also, I think like Puget Sound area on the West Coast was higher and Miami in terms of non native species in those watersheds. But then the Great Lakes was red, which is the 20 to 25% native range. And so is this what they call sort of a beachhead of invasion that is spreading throughout the Midwest into different water areas there, I guess, to ship traffic and, and volume of people and movement and goods and such.
Yeah. Well, the the thing that’s really interesting about that beachhead thing, you think of the example of zebra mussels, in particular, excuse me, and they did come in through the Great Lakes, and then people, everyday people who like to boat would put their boat in a place that had zebra mussels and then take their boat out and then go to another lake that didn’t have zebra mussels. And so zebra mussels have been able to Spread and quagga mussels as well. From the Great Lakes through the Mississippi River watershed, beyond, they’re all the way out west simply because people like to boat in different lakes and take their boats from lakes to lakes. And so there are a whole bunch of campaigns if like you check your boat, wash your boat, all of these things, but, you know, things that you may not think about. But yeah, the beach head the place of arrival for these muscles was was the Great Lakes.
Yeah, actually had a student two summers ago from Baja, who for her IP while we were in Baja, had planned on going home and doing a comparison of she was gonna interview boat owners or something I don’t remember either she was looking at fish stock. I can’t remember exactly what she was looking at. But she was her plan was to do a comparison between the lakes that she knew had zebra mussels. Ones that she knew did not yet have zebra mussels. And by the time she got home, it was like
and so she had to reevaluate her whole project because there were no more. There were no more lakes that didn’t have zebra mussels in them. That’s crazy.
Yeah, the spread the spread has been quick.
That’s, you know, they, they also talked about like the profit fuel pressure, which I think is an interesting term. So like, towards this example, with the muscles like zebra mussels and quagga mussels, you know, if you have more and more people transfer, you know, moving boats between the chance and the proper fuel pressure of like, some of those, I guess they’re transported is there in their larval stage? I don’t, I would assume,
I would assume.
So, like at some point, um, you know, some property duels or just individuals may reach a lake and they may die because they couldn’t survive in the boat that long as it transported there, they get a new lake and it’s temperatures different or something. But if you have more and more properties hitting that lake and more and more chances and rolls of the dice, so to speak, you know, at some point you’re gonna have invasion. So it’s just an interesting term harm. I mean, it really just means more and more chances for
so. So it’s kind of interesting, because this is, to me, this is sort of, again, a language issue. because really what you just described, sort of goes back to the rule of 10, which basically says that 10% of what’s introduced is going to stick 10% of what sticks is going to actually set up a population, and 10% of those is likely to reproduce, and then 10% of those is likely to have some sort of an effect. And so the higher the introduction rate, the higher The probability you get an invasion. Right? Right. There are actually examples and I can’t think of one off the top of my head, but I know that they exist of, of it tensional introductions. Mm hmm. That they add to do multiple times, they had to attempt it multiple times in order to get the introduction to last and there’s one
remember, I feel like it’s something in Australia, where they introduced a species multiple times, because of the benefit they thought they were going to get from it. And when it finally took, it became a problem.
Yes, I yeah. I
think starlings in the United States fall in that either starlings or how sparrows yes into that category.
Yeah, yeah. Well, and I think the there’s also this nice figure in this article figure to where it shows a map of the globe and it has the metal Attorneys basin as a primary source of potential property rules, I guess they can therefore be colonizing California and central Chile because they both have sort of a Mediterranean climate as well. But then California and central Chile can become what they call secondary sources of spread to each other. So even though they’re not the origin of those plants or whatever taxa, they once they’ve set up a secondary, or that first population of invasives in their area, they can be spreading more. And it kind of reminds me there’s this game I play with my family. It’s a board game called pandemic, it’s
it’s all about spreading disease, and you’re like CDC officers. It’s really really fun and awesome. Was that, you know, that was awesome.
I need that game in my life.
No, you would not think you would want to play a game about spreading disease but um, yeah, but it’s but it totally works this way that like you have the origin of the infection. And then like, you know, once it starts to happen from that primary source, secondary and tertiary spread, all of a sudden you’re you’re very quick to get to a pandemic and lose the game.
So I think something interesting that that figure highlights is the idea that it depends where a trade global trade is. Part of the reason that we’re, the invasive species have become such a problem, things are transported faster than ever farther than ever, in our history. But you can, you can guess where things that are going to become invasive are going to come from right, Mediterranean climates. Like in the Mediterranean basin, those species there are much more likely to be able to get a foothold in places like the Mediterranean climate of California, central Chile, Cape Town, Southwest Australia, as opposed to like the Amazon Basin, or things that I’m so thinking about, like, Where, where things are being traded between can certainly help. Think about, you know, predictions of whether things are likely to be dangerous, dangerous, you know, invasive, potentially.
Yeah. The other interesting thing I got to talk about these cookie frogs.
They actually show up in two papers.
Mm hmm. They showed over where
they weren’t both in two different papers that we read.
Yeah, I know. I know the code. Yeah, that’s it’s interesting seeing the same sort of stories in different papers. For sure that the cookie frogs were one of my favorites as well as the
the Caribbean and plains that we kind of have here.
But yeah, the cookie frogs, it’s it’s just interesting to me how in their native environment in Puerto Rico, they’re actually, you know, like a national animal. You know, there’s a lot of pride about the cookie frogs, and they’re considered to be, I think, overall a positive thing. They’re introduced to fly there, their abundance is so high, that it’s, it’s like, somewhere in here, I think it sounds like 10 times as high as in their native range. And so they’re so loud, they say they can cause hearing loss
Which is crazy.
Yeah, it’s just it’s just that point about like, you know, one species, you know, in one region, it may be a native and beloved and in another region. And baby invasive and a complete nuisance.
Yeah. A female. Okay, Judy,
and while I’m googling of them trying because they’re tiny.
there’s a tiny little guys. And so it’s, it’s amazing to me that something that’s small, can make that big of a sound. Mm hmm.
that part of the
that part of the papers
you know, these other two papers was Mooney is the co author have a distinct human element to it, like, you know, the symbol off paper is very much ecosystem oriented. But these other two, look at both humans as vectors for invasive species and creating, you know, opportunities for them, but also the effects that they have on people and, you know, that’s when you don’t really think about I mean, like, you know, we’re aware of economic losses like, yeah, the losses of property value and things. Yes.
surprised me, I never I never thought about property value in relation to invasives. Mm hmm. So yeah, the 64% drop in property value that would be a
Yeah. Yeah. And the paper that were the first author is, I don’t know how to say the last name but pet char. They talk about things like losses of tourism and recreation. And then that’s where it that’s one of the places that it’s mentioned is the cookie frog in loss of aesthetic beauty. Anyway, like, you know, thinking back to the leaks, again, there are a lot of invasive plants that can make they make lakes much less appealing for boating and other recreational things. So you know, that’s a direct recreation lost to the communities where those lakes are, that people might not come to anymore because they’re not a pleasant place to vote anymore and spend vacation, though some of those maybe not as obvious effects of invasive species.
Yeah, they they call it an invisible tax on ecosystem services. From these the impacts of these invasive species that is rarely included in decision making,
which I thought was just an interesting
was the paper that talked about the intentional introduction of zebra mussels. They deliberately introduced them to clear up the water to improve the clarity. Right not realizing the negative effect that was going to come with that.
unintended consequences. Yep. So many of the
well and I think it’s, it’s interesting because like invasive species are, are often, you know, completely vilified. Right? And one of the points they also make in this article is that it’s never that simple like in a species like the zebra mussel, it has all this, these negative impacts, but it also, so has potentially a few, maybe maybe outweighed by the negative, but they have a few, you know, positives and I think that’s their table. They have like this Fox one and T born.
Yeah, it was just Yes. So they’re the three different examples that they use. They really liked the tables that they set up in here, because it allows you to sort of see that, that cost benefit analysis that they did, right you can care like if you look at Box one table one with the South African eco system, there’s kind of a balance there, there’s more positive
or at least sort of neutral effects.
Or we’re equal to the negative. So it’s it’s, it’s a harder decision to make about whether or not this is a good thing or a bad thing, as compared to looking at the zebra mussel example where there’s much more negative than there is positive and feral pigs as well. If you look at the feral pigs, the positive negative values, the negative is is, at least based on this data, somewhat negative. Now, you’ll also see in there that there’s a lot of insufficient data. Right? So we don’t really know for sure, but the assumption is, it’s probably a problem.
Yeah. Well, it would depend on you know, what your
what your personal spective as to whether you would see it as a net positive or net negative. So for like the pigs, you know, if you’re saying, well, this is my culture, we’ve hunted pigs, you know, for a long, long time. And so this is important to me culturally, then that might be more important to you then, you know, stuff like the fact that they have negative influence on erosion and water quality, like, you know, whereas if you’re someone who really, who values, that ecosystem service, the water, the clean water and stuff, and then you might see it as a net negative, right.
Yeah, is this is the paper where they talked about cost benefit analysis done, isn’t it?
Yes. And they also mentioned it in the mayerson and Mooney.
Yeah, that’s it. I think that’s one of the things that doesn’t happen. It kind It goes back to what we were talking about earlier that there’s very rarely a multi faceted approach to studying invasives it’s always very direct. And because of that, we tend to miss a lot of the
Oh, what’s the word? I’m looking for? The sort of
like it really wants it, sir.
Yes, the nuances associated with it
that are important, and they’re important to consider,
right? Anytime you’re thinking about, you know, people, anytime people get involved
in that component, it gets complicated, right, if people people are complicated, we have diverse perspectives diverse, you know, needs and wants and things. And importance on you know, we place depending on who you are different importance on different aspects of you know, The world. And so you factor that in and it becomes Yeah. complicated.
Yep. Right. Yeah, we all want a simple narrative or not we all I guess, I guess sometimes the media sometimes, you know, people want to have simple actions that they feel like are good, quote unquote good. So I’m going to go out and remove honeysuckle from my native forest and that is 100% good for all species in the area, or I want to believe that many of us saying well, actually honeysuckle might be really good for certain pollinators or certain bird birds because it does produce, you know, whatever. And you start to complicate the issue. People don’t necessarily want to hear that either. Oh,
Yeah, speaking directly to the honeysuckle thing. There is evidence that shows that with how high our deer populations are, if you feel the honeysuckle and leave it in place, it’s actually better for spring of emeralds because otherwise the deer can get to them when the honey circles there, it’s harder for them to get to all of the all of the spring ephemeral. So interesting. Yeah, so honeysuckle, again, bad good.
Yeah, I guess I would encourage people anyone listening to this or others like, like, I’ve always felt like, you know, to look closer at what is, quote unquote good and bad, like we’ve already said, also to use more precise terminology in terms of whether you’re saying non native, whether you really mean non native or invasive or what ways you’re used to seeing that. Those are some of the major takeaways for me from these articles, and also, all the indirect effects that some of these things can have that might not be easily measurable or quantifiable.
Yeah, I would agree with that. I would say you know, black and white is just not a thing that exists in the world. There are there there are 100 Shades of Grey, but it’s almost impossible to Find something that is 100% good or 100% bad. Usually those things end up being wiped out in one way or the other anyway. Yeah.
For, for me, I really appreciate it. The idea that, you know, as ecologist is conservationists, we need to kind of step back from, from just the invasive impact on ecosystems and kind of think more about what does this mean for people? And how do we translate what we’re talking about into economic terms, which is easy for people to understand, across the board, you know, businessmen care about economics, they don’t necessarily care about, you know, the fact that cheatgrass is changing the sagebrush steppe in the western United States into grassland instead of shrubs, you know, but if you can show them that this affects them in some way, economically, then they might care. The other thing that I found interesting and this is going back to the Mason and Mooney article is is an all of them really is for the things that we don’t know. You know, we don’t necessarily know what makes species invasive, we can’t predict that with, you know, great accuracy yet. We have some things that that tend to be indicators of that but you know, and then the tax that we have studied, we haven’t studied all tax, that there are a lot of taxes that we haven’t really thought about in terms of invasiveness and how to predict that not. So those things again, you know, thinking about, yeah, the broader human impacts and the kinds of information that would be really useful for us to to be able to gather and understand as we’re thinking about these problems,
Totally agree. You know, The the need to work across. It’s actually something I tried to make happen at the University of Louisville. I tried to encourage a cross listing course, between the biology department and the economics department because it was working with the economics faculty at the time. And it never actually happened. But it’s something that I would think in research, we would want to be working more better getting out of those silos, and absolutely, our little science bubbles, if we really want to have any sort of policy effects, because you know, the way things are going now science is not is not enough.
Any other last thoughts as we wrap up this, the second podcast?
I think we’ve covered it pretty well. And yeah, no, I mean, there’s always more to talk about so many things. Sacred samples, but I think some of the bigger themes and yeah, no, it’s super fascinating, important things to be thinking about.
Yeah, I agree. I think this is gonna be a fun discussion.
Yeah, definitely. All right then. We’ll chat again later and catch everybody in the discussions. Thanks for listening.
Take care. Thanks. Bye bye