How Detrimental Are Non-Native Species?

: Winter: One of the things which always people tend to say, an invasive species is always very abundant over growing things. But that happens also for native species. It could be just a native plant, which is just in this case, and these little habitat and ecosystem, a very abundant species that happens also in native ecosystems. We have sometimes forests, beech forests. Only the beech lives there. And how could you say that? This is not that. This is different to a bamboo forest on the Azores, which I have seen for hundreds and hundreds of metres only bamboo.

00:00:35: Hahn: Welcome to Inside Biodiversity. This podcast is hosted by iDiv, the German Centre for Integrative Biodiversity Research. My name is Volker Hahn. I am head of the communications unit at iDiv. Today's guest is my colleague Marten Winter. Marten leads our synthesis centre sDiv and he's also a highly cited researcher in the field of invasion biology. This is a discipline that investigates the impacts of species that have been introduced by humans to new ecosystems outside their native range. And this is exactly what we'll talk about now. Okay, Martin, welcome to Inside Biodiversity. Why did you become an invasion biologist? What is so fascinating about it?

00:01:24: Winter: Uh, I think it was rather by coincidence. So I was a wildlife ecologist by training when I finished my studies and already did my master thesis about the North American raccoon in Saxony-Anhalt. So I started already as the master's thesis with a non-native species. And this was rather a coincidence. My professor gave me a couple of topics, and I wanted to do something with fieldwork, and also with computer work and with a mammal, and that that was what my professor was suggesting. And and then based on that work, I coincidentally and and also happily ended in a in a group which was doing quite a lot of research on non-native species, which was the lab of Ingolf Kuhn at the Hamer Centre for Environmental Research. And so I started to grow as an invasion ecologist.

00:02:14: Hahn: Very good. So invasion ecologists deal with alien species and with invasive alien species. Those are.

00:02:22: Winter: Two.

00:02:23: Hahn: Terms that sound similar, but they don't mean the same thing necessarily. Can you define what is the difference between an alien species and what makes it invasive?

00:02:34: Winter: Yeah, first of all, alien might be also not necessarily the term many people or all people use there. There are other terms which are sometimes used in the same manner, like exotic or non-native, which I guess is the most scientific term alien species is for the majority of scientists, I would say, an organism that is not native to a certain area and once introduced and established. It can be called as an alien species, as an established non-native species as you want, and an invasive species is the next step in the different steps of this process of an invasion. Invasive means can cause environmental or and or economic negative impacts. It is a non-native and established non-native species which with negative impact.

00:03:28: Hahn: Okay. We'll later talk about different negative impacts through invasive alien species. But just to get this clear, there are also natural processes how species can arrive in a new place where they haven't been native until then, if that new species is introduced through another species because, for example, a plant seed is stuck to an animal that migrates. And if that happens nowadays, this would not be considered an alien species. Or would that also be an alien species? Is that clearly defined?

00:04:07: Winter: Um, yeah. I should have potentially said that the definition of alien species the district, as one has included, includes the term or words, depending what definition you you like most human driven introduction. So an introduction driven by humans. Um, so either as a hitchhiker or deliberately introduction, whatever. And then you can still argue, which we also have nowadays species which move through space because of climate change. And so is that a non-native species like the golden Jekyll maybe now or which moves through Europe and it's not driven by humans, it's just moved through the landscape organically. I don't know, and I think there's some terminology discussion ongoing in the, in, in the scientific realm, actually quite a lot because people also discuss if we should at all look at species and defining them by origin, and maybe not by impact or by other means. And if a species is hitchhiking on another species, and if there's no visible human impact or human support, I would say it would not be considered as a non-native species. But for these specific cases, I must confess that I'm not an expert, and I also try to stick on in the field of research, which I'm most confident with in terms of definitions, which are usually those species which are introduced and distributed across the planet via human activities.

00:05:41: Hahn: Um, does it also make a difference when a species was introduced to a new area like 500 years ago, maybe thousands of thousands of years ago. Like, for example, the the house mouse or the brown rat from Asia were brought to Europe a long time ago.

00:05:59: Winter: Yes. So there are some also there are limits. Yeah. Because some areas in the world have seen ice. Ice ages. Others not. And biota always changed because of large processes. So the strictest definition, and it's also one I feel most confident with, is that we make a distinction at 1500. So the best basically was the was the exploration of the start of the exploration of the Americas, uh, due to um, the, the explorers and which was around 1500, which marks basically the starting point of a larger globalisation. So we, we say a non-native species in an area as a species which arrived after 1500. But there are many species of which we know, especially where we have stronger and more research. That species were distributed already before that, because humans travelled across the planet already before 1500, obviously, and especially in Europe, there's a strong community for for these data and for this knowledge, and we call them arco sites for plants or archosaur for, for, for animals. And this is specifically these are specifically species which we know maybe arrived in Europe before 1500. For example, with the changing human land use, open landscapes and certain for example, Central Asian plant species arrived with humans and with seed contamination, which are now known to be here in Europe since over 500, sometimes thousand years, which is in other countries not so much known because we just started to explore by authors 1500, for example, in South America. So we only have a little bit of knowledge of what species were transported in these places. Of course, like potatoes or tomatoes where transported or corn. Maze was transported across the Americas before them. But usually the Cut-Off point is 1500 after 1500.

00:08:04: Hahn: Okay, so that's what the researchers decided to to set as the the baseline. We already heard that there are alien species. Species, but not not all alien species are invasive. Not all cause problems. But to make this concrete, can you start with an example of a species that was introduced through humans within the last 500 years to a new area, and that does cause problems, so that we get a feeling for the type of problems we're talking about here.

00:08:38: Winter: Yeah, maybe I give I start rather the opposite, talking a little bit about the problems and then can can give some examples. So the typical problem often of a non-native species is a competition. So that shows that that some of these non-native species are very good competitors compared to the native species. So the new species for them. So competition which can lead to domination of certain species of the non-native species, which can lead to the local extirpation of species which would otherwise live there. That's that's one of the main, main processes how a non-native species can have an impact taking resources which otherwise native species which would have used, like also for pollination and all kinds of other resource relevant processes. Some of these non-native species are even more than just strong competitors. They are engineers, ecosystem engineers. There can be so dominant in there. Not necessarily behaviour, But just occurrence that they change more than just a local extirpation of few species or just a decrease of abundance of species. So for example, I shown you a crassipes, which is the water hyacinth which can grow massively on water surfaces and was introduced, for example, to Africa and leads to in some water water areas to so dense populations that change the whole physics and chemistry of the water bodies, because no light can enter the water and and it leads to the change of whole ecosystems. And and that's, that is one example of several other species. There's also kudzu is another plant which can grow per day a couple of metres, I think even. And that can overgrow in very short time if the resources and the climate matches in very short time. Other ecosystems. So competition resources. And there are some processes which allow these species to be so successful. But usually these are some of the of the reasons why non-native species become invasive.

00:10:55: Hahn: So you mentioned an example that is a plant. From what I heard, plants in general or on average cause less problems than animals. And in some cases the places where they become abundant might even benefit from a human perspective. For example, the island of Madeira, Portuguese island in the Atlantic, has about 400 new plant species. About one third of the flora on Madeira now is, well, basically exotic plants. Would you agree that this is an example of new alien plant species that are not invasive, or are some of these invasive in the sense that they do cause problems.

00:11:41: Winter: Yeah, it's a very good question. Of course. Um, if we just stop and counting species and seeing that more species are an indication for higher biodiversity, for maybe a better ecosystem, then you could say this addition to the in this case, Flora of Madeira is maybe not not at all causing problems. But some of these species and Madeira are causing problems in a way that they change networks of interactions. Not all of introduced species become a problem. And for the majority of species which are transported across the planet, we don't even know what is their effect on ecosystems. It's just too many, and sometimes also very tedious to find out. But there are. I've been on Azores, which is a group of islands, sister to Madeira and similar a set of introduced species, and some of these species are very abundant and led to a decrease of of native species, even if this is maybe not seen as an as an issue because you still see nicely flowering plants. And also we know that some of the plants there, and which are just examples of many plants on other islands, lead also to, for example, disruption of native pollination networks. They are offering different resources for native pollinators and might even lead to the disadvantages of native pollinators and maybe are more beneficial to non-native pollinators, which are often also introduced or other herbivores. So just having a lot of more species not necessarily means something good. But I'd also have to say and it's it's also known and it's not a secret. And nobody hides that, that there are also several potentially many among the many introduced species which have positive effects, offering resources without knowing to be invasive or overgrown other species. So there are examples of plant species, for example, which offer additional nectar resources or being nesting places or whatever. Um, so.

00:13:45: Hahn: To summarise that on Madeira, just as an example, there are few species that cause major problems. And whether you see the overall biodiversity change on that island as being positive or negative is maybe not a fully scientific question, but it maybe depends on on the value. Some might feel that humans have had too much of an impact on that island, and changed the pristine state too much, but others might think, well, they're more more species now than there used to be. And, uh, I like that. Would you agree with that? Or and what's your personal view on that?

00:14:25: Winter: I can imagine that people see it as a positive thing. Madeira is known as the Flower Island or the Garden Island exactly because of that. Yeah. My numbers actually tell me that we have more an established, non-native species than established native ones on Madeira. There are a couple of islands where this is the case as well. I'm as a my personal opinion as a scientist, I think this kind of reshuffling of biota is rather negative because we lost the distinct and Madeira flora as a, as a, as an interesting group of islands with an interesting history, had had a very and still has, but with much lower numbers of individuals, a very distinct flora, which is now rarely seen, and you only find a little pockets where where these plants and other animals and other species still exist. So I personally think this reshuffling of the biota is rather a negative thing because we we lost some ecosystems in its natural way. But on the other hand, I also know that this is something we can't you know, we can't go back. In most cases. Okay.

00:15:33: Hahn: Yeah. Okay. Let's talk about another example that you have looked at a lot in your research. The raccoon. The raccoon originates from the Americas and has been introduced in the 20th century in Europe and is now very abundant also in Germany, where we are sitting right now. What are the problems that the raccoons cause? And in what way are they different from the problems they cause in in America?

00:16:04: Winter: Yeah. So I start with the second. It's different there in the way that the raccoon is native in North America or in the Americas, and it has natural enemies, which we don't have here. People now argue the wolf is taking over in Germany, but it's not abundant enough to be a natural enemy. Yeah. So what is.

00:16:27: Hahn: Different takes over in the sense that it reduced it would reduce the number of raccoons.

00:16:32: Winter: Right. So we don't have a natural enemy in Europe of the raccoon. And of course, the raccoon is sometimes the victim of eagle owls or. Maybe young raccoons are hunted by foxes or something, but it's nothing. Which is like in North America, where the raccoon has, first of all, natural enemies. So other predators and also is the major rabies vector, which also reduces the amount of individuals of raccoons as a natural disease.

00:17:03: Hahn: But do we have a higher density of raccoons here than in North America?

00:17:06: Winter: Partially, yes. In the in the core of the distribution in Germany. And parts in some areas, yes. Also in North America, the density is quite different. And depending where you are, although the raccoon has certain preferences in terms of habitat. And what is the effect of the raccoon in Europe or in Germany? That's a very good question. And and it's the first of all, I think it's whom you ask. Second, how much you believe in correlation versus causation? Um, and I, as a researcher, I would say we estimate that we roughly have 1.5 million individuals of raccoons in Germany only. And that, of course, as an omnivorous species, causes issues. And we know that the raccoon eats almost anything the species can find that can be ground nesting bird. That can be all the cherries in your garden, that can be all frogs in a pond. And that, of course, with 1.5 million individuals, affects a native ecosystems. It would be naive to say there's no visible effect. But from a scientific perspective, we lack evidences of the absolute effect on on native biota. We know that there are local, local issues. Uh, it can lead to the to the local loss of, of birds because it's too often preying on those birds and then they would move on. One famous example is the very rare European turtle we have in in Germany. And it's known and there are many evidences that the raccoon is preying on this turtle, which is of course, in this case can even lead to the extinction of this species in Germany. And there's management which happened, but this is at the moment potentially the only known example. I'm, I'm aware of where we directly with a causal relationship can say that the raccoon leads to the extinction or almost extinction, local extirpation of the species, but nevertheless we know it eats a lot. It's extremely smart. It can. It fills a niche which we don't have in Europe of a climber. Messel predator, which is which is can do quite a lot with its limbs. So there is an impact for sure, but we don't know. Let's say if we have decreasing bird populations, we don't know if the raccoon is the reason or is it the multitude of climate change, land use intensity, and an additional predator next to the native predator. Next to the free ranging cats. So we don't know yet, but it's very likely that there are effects.

00:19:36: Hahn: So there are alien species that most people would agree that they do not cause major problems. Then there are alien species, or we know that they do cause problems. In other cases, probably many. We just don't know. And in some cases it's debateable. The example of Madeira. Some might think it's good, others might think it's not so good. But in the cases where we agree that there are problems associated with that species, there is then the next problem. What should we do about it and what can we do about it? And maybe we'll start with the raccoon. If we would agree that the raccoon does cause problems in Europe, what could we do about it?

00:20:20: Winter: Yeah. Good question. So there are a successful management measures you can do if you want to manage the raccoon locally. And that's the only thing you can do. So you can only manage invasive species like the raccoon which is a mobile vertebrate, a mammal locally. So what we just right now doing here in Leipzig is we have a we have a few ponds. And there's one point which is relevant for a certain amphibian species here, which is close to a nature conservation area. And the local conservation authorities wanted to protect this pond and hopefully breeding amphibians in there. And there's very simple measures like electrical fence around these pond, which you can apply if you do it properly. It's known to be an effective measure to keep the raccoon out of, for example, this little local area. Of course, that doesn't work with a forest of several square kilometres and other things you can do. The raccoon, for example, is a very good hand to build. With live traps. You have to be an allowance for that, and if you want to really minimise a local population of the raccoon, you have to do this very properly for quite some time and intensity and that costs money. And then I want to say that the raccoon is then killed. Obviously it's not released ten kilometres somewhere else because that is not the management of an invasive species. So there are ways locally to manage raccoon for example. Also where the raccoon creates problem is predating on nests, on bird nests, very often on raptors which are very often conservation relevant. And you can prevent raccoon from climbing up trees with certain measures. You put things around the trunk, you cut some branches, etc. and these can be very effective. But what you can't do is managing a species like the raccoon. And this is just one example of a widespread non-native species which are highly mobile Bile on large scales that you can do that in a world of unlimited resources. But I'm not aware that we live in a world of this for conservation. It's just not the case locally or in areas which which might be like islands or specifically on islands, you can manage non-native species depending on which species. If they fly. It's also a bit more tricky, but there are many cases and many combinations of the regional setting and the non-native species that which doesn't allow much of the management.

00:22:47: Hahn: So you mentioned that managing invasive alien species is oftentimes associated with killing these animals. And in some cases humans use poison for that. Like for example, in Australia, the red fox, which is an invasive alien species, is killed with poison bats. And that is very painful for these individual foxes to die that way, and it's quite uncertain whether, you know, Australia is big. How much that actually helps, because you will probably never eradicate the fox from from this whole continent. What do you think about that? Is that a good idea or how should we weigh the well-being of these foxes with our wish for a continent with less alien species?

00:23:42: Winter: Yeah, very good question. I think also, this is a huge debate in Australia among scientists and animal welfare. Welfare, for example. Um, I don't know. First, first of all, I think, um, the reasoning behind that is that Australians or those in charge of these decisions for large scale baiting, decided that the very distinct and endemic biota on Australia is worth to accept. Having some of these animals there, which maybe are competitors to the red fox, which will would die if they also take up these baits versus the effect the red fox has on average, on the whole biota. It doesn't lead to the eradication. Although Ausra is an island. It's just huge as a continent. It leads significantly to the reduction of numbers of red fox, and with that to the reduction of its impact. So in this case, I would say it's something I think it's okay. You can do this. You you you can. It's further, let's say if you say it for the greater good of the biota of the native biota in Australia. Even if you lose individuals also of native biota in the end, I think and that's what I where I would trust my colleagues that they made an assessment and saying we lose native biota, but with less red fox we gain actually more of the native biota or we reduce the losses even more, right?

00:25:11: Hahn: Um, it has to do with how much you value individual of a species, or maybe independent of the species and, uh, the species itself.

00:25:21: Winter: Right. It's all about which species do you value more? Right.

00:25:24: Hahn: Well, not only about the species, but also how do you view the individual's right and the pain that you cause to the individual folks?

00:25:32: Winter: Right. Right. Um, and, um. That's it. And if you. But if you know the numbers, how many other vertebrates the red fox prey on per year, millions of birds and lizards and other vertebrates. The the foxes kill then. And if you would say you could reduce that by half, maybe 500,000 less killed individuals of native biota versus maybe I'm just making these numbers up several thousand kills, red foxes and several, maybe a few hundred or even less. I don't know of native other animals who take up the baits then. Then this is this is a calculation people have to make and people made obviously in Australia. And yes, I'm pretty sure I'm not an expert and I'm pretty sure this is. These are hard decisions. And the same goes for the cat, which is also the similar story in Australia and many other places in the world. Even more because cats are, you know, our friends live with us compared to the red fox. I think these decisions are heavily debated and it won't stop. And there might be less debated because baiting happens also with invertebrates. Ants, for example, which are create a huge issue as invasive species everywhere in the world. There are less debates about that because, you know, less strong animal welfare discussions around invertebrates. But yes, it's a it's a it's a matter of value. And also some, some discussions we as scientists have to have very often with people who have, you know, who have other values in these cases. Yeah. Yeah. It's I just want to say it's very tricky. I'm sure we could debate this for, for ages.

00:27:08: Hahn: I'm sure it is, because, as you mentioned, also in nature, there's a lot of killing and pain ongoing because that's how nature works. Yeah. Um, but this example of the red fox in Australia points to the fact that a lot of killing of alien species by humans is happening on islands and island continents, and the reason for that is that the problem of biological invasion is more pronounced on islands, and most of the extinctions caused through biological invasions actually happened, almost all of them probably on islands and island continents. Why is it that biological invasions are much more a problem on islands than, for example, in Europe and Asia?

00:28:02: Winter: Yeah, also a good question. And that's obviously also a field of science, which I was also partially part of one of the reasons, or one of the evidences we see in our data is naivety. So the native biota on islands are very often, um, have not evolved with predators. So New Zealand is a very good example. Also Australia and in some other islands have not co-evolved with certain types of predation or even with predators.

00:28:32: Hahn: Like birds that cannot fly.

00:28:33: Winter: Birds that cannot fly right. Regions which don't have any, uh, walking on the terrestrial walking predators. So then a rat, or in this case a rat or a fox or a marten. In this case, my name is a is also an invasive animal in many places of the world, can create very easily and very enormous effect on on other species because they are not used to those kind of behaviours, and also very often these ecological niches of species on islands are very small, very specific due to isolated evolution, etc. and then a very general or species invasive species very often have general traits, are opportunistic in their behaviours, for example what they eat and how they live, where they grow, what resources they need can then over overcome these niche specialist species, which more often happening on islands. And on the other hand, there's no way to escape that place. Also a role if the climate matching, which is the most important filter for the establishment of non-native species, is this is overcome, then very often these species, which are good competitors because of certain traits they have, they can just, you know, grow and live on an island where the the native biota has no chance to escape. And, and, and um, like in Europe, as I said, the raccoon leads to two birds which just take, you know, fly ten kilometres further away and then nest there. And on islands, that's often not possible.

00:30:11: Hahn: I have a question that's probably challenging. Let's see if you would go to a place that you didn't know at all. You wouldn't know any of this species, but you could measure everything. Could you identify those species that are native versus those that are alien because they cause problems?

00:30:34: Winter: That's a that's a good question. And I've been at places like this, but then I knew also parts of the parts of the species. For example, I can take the example of my kids. We were on the Azores, which is the heaven and hell for invasion biologists. It's a among, I would say, among the hundred top invaders on this planet. I would guess, at least on the from the plants, 80% occur on that island and my kids don't know them, don't know these plants. They were there and they enjoyed the green lush plants and an ecosystems. They're a lot, and we're not aware that the majority of these plants were just a combination of South American, Japanese and African plants whatsoever. I think I would not be able 111 of the things which always people tend to say, an invasive species is always very abundant over growing things, but that happens also for native species. It could be just a native plant, which is just in this case, and these little habitat and ecosystem, a very abundant species that happens also in native ecosystems. I would say maybe I should know, not so often, but I know cases we all know species. Also, we have sometimes forests, beech forests. Only the beech lives there. And how could you say that this is not a that this is different to a bamboo forest on the Azores, which I have seen for hundreds and hundreds of metres. Only bamboo.

00:31:56: Hahn: If you wouldn't know that the beach is native to Europe, right?

00:32:00: Winter: It could be.

00:32:01: Hahn: It could be invasive.

00:32:02: Winter: It could be invasive. I'm. Maybe there are hints which I'm not aware of. From other, you know, scientific fields, which could give a hint, but it's a good question. I think I would not be able. There are some, some maybe behaviours of, of of species if you see them very abundant, let's say animals very abundant and you don't see many other species. And you may maybe see also predation happening on across all taxa. So one species predates on a lot of things and it's very abundant. Maybe that would be a hint. But there are also abundant animals on islands which are native, like the, you know, partially the legal iguanas on the Galapagos. Yeah. And they are iconic species there.

00:32:44: Hahn: So we've already heard that invasive species play a bigger role or more problematic role on on islands. Also animals seem to be have a bigger impact then plans. Let's zoom out a little bit. How many of all alien species globally are. Invasive?

00:33:08: Winter: Yeah, it's a it's a good question. So I, as a scientist, as an invasion ecologist. Grew up with the 10th rule, which says that every step in the process of an invasion, every barrier is only done by 10% of the species. So 10% of all introduced species establish the other species. Just don't make it because of an environmental filter. For example, 10% of those species which are established non-native spread and become invasive. The latest report and which is great, and I can only recommend to read at least a summary for policymakers of IPS of the IPS report on invasive alien species showed exactly this number. They counted all non-native species we know across the taxa, which is an absolutely subset of what is actually going on. And and found out that I think it was roughly 37,000 species they had in their numbers, and roughly 3500 of them were meant to be invasive somewhere in the world. So that is 10%. But if you if you if you look deeper into the different taxa, animals are different than plants and vertebrates different than invertebrates. The numbers appear to be a bit different then, for example, that it's double the size for invertebrate, so roughly 22%, I think, of alien invertebrates. Established alien invertebrates become invasive. Uh, it seems to be 14% of vertebrates. All the numbers even suggested higher numbers, but now it seems to be 14%. And for example, only 6% of plants of those established non-natives become invasive. So roughly, I think the 10% rule seem to be still valid, but different across the taxa.

00:34:45: Hahn: Does this uncertainty or maybe disagreement among scientists, does that also have to do with this definition of what is invasive or not? maybe is a bit blurry, depending on what you consider a problem and what you do not consider a problem.

00:34:59: Winter: Definitely, yeah. The definition of invasiveness is there is a scientific definition, but then defining what of this is a problem which is already a very anthropocentric view. Is is a hard to mate scientifically comparable across systems? Yes. That is one issue of that. Very often a list of invasive species per region is also a political issue, because then it might point to priorities in conservation and spending of money. And also it's a lack of knowledge for many regions. We don't even know what is native and non-native. Specifically, in biodiverse, highly biodiverse regions in the tropics, we still count biota without knowing if this is a tree. We see here that a native and non-native tree, we just see it for the first time here. I think it's a mixture of different things, and that's why I, for example, work very rarely with number of invasive species.

00:35:52: Hahn: Do you consider humans part of nature? And I'm asking that because the whole concept of invasion biology seems to separate humans from rest of nature. What's your view on that?

00:36:06: Winter: Yeah, no, I think, uh, we as humans are the most invasive species on this planet. Um, in the way of if you think about impact, um, and also, there are regions. Now, I'm also walking on, on, on thin ice, at least from my own, uh, from my own experiences, there are regions where humans maybe haven't lived. There are islands which were not inhabited for longer times. Um, on the other hand, you could always argue that there are many regions where humans have lived for as long as humans maybe have lived there, like in the Amazon, uh, indigenous people. And they have lived in a kind of equilibrium with the, with nature. And they haven't transported species so much, that whole ecosystem change. So I think if you want to say humans can be very invasive in terms of impact, we change ecosystems. We are the biggest engineers here. Um, maybe next to ants. Yeah we are. Well.

00:37:05: Hahn: But but an alien invasive species is also part of nature. And I think that's that is not contested. Right. My question was are we part of nature and not are we invasive?

00:37:17: Winter: Yeah. Okay. Yeah. Then, uh, are we part of nature? Good question. Uh, I don't know. I think so, in a way, yes. But we are also relatively young. If you say if you see it, uh, we are we we could say we are different because we are. We have skills and traits which makes us different. Although we are animals. Where, um, are we part of nature? Maybe. Yes, we are an evolved species as part of nature, coming out of species, coming out of nature. But we are not the best part of it. Let's let's maybe. Stop. Stop it. Here. Okay.

00:37:50: Hahn: Yeah. Okay. Yes. Uh, we also have been talking for quite a while, so let's come to an end. What would you like the audience to remember from this conversation? In a nutshell, what's your what's your takeaway?

00:38:04: Winter: My takeaway would be, first of all, that. That everyone realises that aliens are everywhere and we haven't touched but haven't touched the topic. But microbes is a big issue and an growing issue with ongoing globalisation and they are invisible, but they are everywhere in the air, in the soil. So non-native species are everywhere on the planet. There's basically no place on Earth which we humans haven't touched. And with that also isn't isn't invaded by a certain organism. And, and I think every one of us who is listening to that great podcast series here can take, can make a little bit. Yeah. One when we travel, look at down at your shoes, at your luggage. Try to avoid transport proper ghouls, seeds or whatnot living species across the planet. Try to minimise the introduction of species. And because many of us potentially have a garden or something. Just think about what belongs in your garden. And there's no need to plant species which is known to be invasive somewhere because they make maybe next year the jump across your fence and and are an additional new species to an already quite stressed ecosystem.

00:39:15: Hahn: Cool. Yes, we want this podcast to have an impact and maybe this statement can make an impact. Thank you very much, Martin for this great conversation.

00:39:24: Winter: Thanks for the invitation.

00:39:26: Hahn: I hope you enjoyed this episode of Inside Biodiversity. We would like to learn more about how you like the show, so if you have any thoughts on that, please write us an email at podcast@idiv.de. Also, make sure to follow us on social media–on Bluesky, LinkedIn and X.