Photo by Eric Higgs
Summary
What can a brand new patch of nature tell us about Europe's ancient history?
In this episode, we touch down in the Netherlands, where an unconventional experiment (the Oostvaardersplassen) has shaken up both the field of ecology and Dutch society. What started as a bird watcher’s obsession with thousands of trekking geese, led to a criticism of one of the central tenets in ecology: ecosystem succession.
Enter a counter-theory that would return the rarest of birds, butterflies, and a once-extinct mega mammal to one of the most densely populated countries on earth.
Show Notes
This episode features the voices of Koen Arts, Frans Vera, Perry Cornelissen, and Gemma Venhuizen.
And was produced by Toon Vos and Mendel Skulski, with help from Adam Huggins and Lili Li.
Music by Francesca Vincentie, Museum of No Art, César Franck, Vincent van Haaff, and Sunfish Moon Light.
Special thanks to Penny Green, Isabella Tree, Charlie Burrell, and Gina Maffey. Dutch-speaking science and nature lovers may also enjoy Gemma’s podcast: Onbehaarde Apen
✨ And as always, this episode was made possible with the support of our amazing patrons. 🌱
Photo by Erwyn van der Meer
Citations
Arts, K. (2021) Wild Jaar: 365 nachten buiten, Noordboek Natuur.
Bakker, E.S. et al. (2016) Combining paleo-data and modern exclosure experiments to assess the impact of megafauna extinctions on woody vegetation, Proceedings of the National Academy of Sciences.
Berendse, F. (2016) Wilde Apen: Natuurbescherming in Nederland, Knnv Uitgeverij.
Cornelissen, P. (2017) Large herbivores as a driving force of woodland-grassland cycles : the mutual interactions between the population dynamics of large herbivores and vegetation development in a eutrophic wetland, Wageningen University.
Green, P. (2020-present) The Knepp Wildland Podcast.
Smit, C., Putman, R. (2011) Large Herbivores as 'Environmental Engineers' in Ungulate Management in Europe: Problems and Practices, Cambridge University Press.
Tree, I. (2019) Wilding: The Return of Nature to a British Farm, Pan Macmillan.
Vera, F.W.M. (2000) Grazing Ecology and Forest History, CABI Publishing.
Vera, F.W.M. (2002) The Dynamic European Forest, Aboricultural Journal, Vol. 26.
Vera, F., Ruben, S. (2013) De Nieuwe Wildernis: Grote Natuur in een Klein Land.
Vera, Frans (2017) Freeing the Landscape: Grazing Animals as Ecosystem Engineers, Kneppflix.
Yin, Steph (2019), The Netherlands’ Grand Rewilding Experiment, Gone Haywire, the Pulse.
This episode includes audio recorded by Benboncan, felix.blume, klankbeeld (2) (3) (4) (5), 13gkopeckak, killyourpepe, RobertMThomas, Benbojangles, arnaud coutancier, d.n.audio.uk, D4XX, TheNaturalWorld accessed through the Freesound Project, and protected by Creative Commons attribution licenses.
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Future Ecologies is recorded and produced on the unceded, shared, and asserted territories of the WSÁNEĆ, Penelakut, Hwlitsum, and Lelum Sar Augh Ta Naogh, and other Hul'qumi'num speaking peoples, otherwise known as Galiano Island, British columbia, as well as the unceded, shared, and asserted territories of the Musqueam (xwməθkwəy̓əm) Squamish (Skwxwú7mesh), and Tsleil-Waututh (Səl̓ílwətaʔ/Selilwitulh) Nations - otherwise known as Vancouver, British Columbia.
Transcription
Introduction Voiceover 00:01
You are listening to Season 4 of Future Ecologies.
Adam Huggins 00:06
Are we all recording locally?
Toon Vos 00:07
Let's see. I got signal. Yes. Okay.
Mendel Skulski 00:13
Okay. I'm rolling.
Adam Huggins 00:14
Okay. I have – I have absolutely no idea of what we're going to talk about. Really. This is a first for me.
Mendel Skulski 00:23
But you know why we're up so early in the morning?
Adam Huggins 00:26
What time is it there for you, Toon?
Toon Vos 00:28
It's five past three in the afternoon.
Adam Huggins 00:32
Oh, that's nice.
Toon Vos 00:33
Yeah, it's just the middle of the day.
Mendel Skulski 00:37
I guess that should make the point clear that we are up earlier than we'd like to be to record this podcast, because we're getting a little bit outside of our own backyard today. We're going to Europe.
Mendel Skulski 00:51
Oh right! Um, we should introduce ourselves. My name is Mendel.
Adam Huggins 00:54
And I'm Adam.
Toon Vos 00:55
Nice.
Mendel Skulski 00:56
You too.
Toon Vos 00:57
Oh, sorry. My name is Toon. I'm from the Netherlands. That's a little European country people sometimes confused with Denmark. But we're the one that has Amsterdam.
Mendel Skulski 01:08
Right. Tell us a little bit about the story you've got for us today.
Toon Vos 01:11
Yeah. Today, I'd like to invite you to the bottom of the sea, because there are some interesting creatures living there, as you may know. More specifically, the animals that graze there.
Adam Huggins 01:24
Like sea urchins?
Toon Vos 01:25
I'll give you a little hint.
Soundscape 01:26
[Sound of burling Red Deer]
Mendel Skulski 01:26
[Laughs]
Adam Huggins 01:32
Wait, that does not sound like any animal I know from the bottom of the ocean.
Mendel Skulski 01:35
That sounds like a deer!
Toon Vos 01:37
Yeah, the bottom of the sea I'm talking about is a polder. Do you know what that is? A polder?
Adam Huggins 01:44
A boulder... like a big rock?
Toon Vos 01:45
No. So a polder is a tract of land that used to be underwater. So that could be a sea or a lake or a marsh. And then at some point, humans decide that they're going to drain it. They're going to pump out all the water. Usually, windmills were used to pump out the water beyond the dikes, draining the water out of the area. And basically creating land where there used to be sea.
Adam Huggins 02:11
Famously, you come from a country that is underwater. I understand.
Toon Vos 02:14
Yeah, Atlantis.
Adam Huggins 02:15
Right. Okay, so a polder is a is an area of land that has essentially been reclaimed from the ocean. Would you use a word like that: "reclaimed"?
Mendel Skulski 02:24
Claimed for the first time, maybe...
Toon Vos 02:26
Exactly. That's the interesting part. People always say "reclaimed". But maybe claim is a good word. I don't think we were particularly entitled to the bottom of the sea, but people wanted to farm.
Toon Vos 02:38
So once you have poldered this land, you have land where there used to be water, you can do all kinds of stuff with it. So the soil becomes super fertile. Often it's used for agriculture. But the Dutch were like "We have 11 provinces... that's nice. But we want 12"!
Adam Huggins 02:56
[Laughs] Of course
Toon Vos 02:59
So they decided to create another province, which they called Flevoland, and it was created between 1918 and 1986, which is really young.
Adam Huggins 03:10
So they just up and decided that they wanted to make their country larger. And instead of doing it, I guess the normal way, you just basically make it out of the ocean.
Mendel Skulski 03:17
Preferable to invasion.
Toon Vos 03:19
Yes, they invaded the water instead. But there's a saying: "God created the world, but the Dutch created the Netherlands". It's a bit much, but you get the sense of pride that is felt.
Toon Vos 03:33
And in the polder of Flevoland, this new province, there is the great wilderness that we call the Oostvaardersplassen
Adam Huggins 03:44
Um.. one more time?
Toon Vos 03:45
The Oostvaardersplassen
Adam Huggins 03:48
The Oostvaardersplassen...
Toon Vos 03:51
Pretty good! Mendel?
Mendel Skulski 03:52
Oh, for me. Oh, jeez. Oost... vaar... ders... plassen.
Toon Vos 03:58
Oostvaardersplassen. But if that's too Dutch for you, you can just call it OVP
Adam Huggins 04:02
OVP.
Toon Vos 04:04
So you have the Oostvaardersplassen, and the train from the city of Almere to Lelystad (which is the capital of Flevoland) will take you right past.
Toon Vos 04:15
I asked Koen Arts, a nature writer and researcher at Wageningen University to describe the Oostvaardersplassen for us.
Toon Vos 04:23
For someone who has never seen the Oostvaardersplassen, what is it?
Koen Arts 04:29
Yeah, that's that's a funny one because I think for a lot of foreigners, it's... it's unlike anything they've seen. So, imagine a small piece of land: about 5500 hectares. So when you talk about nature conservation on on the global level, usually, nature reserves, national parks are much much bigger.
Koen Arts 04:50
On multiple sides, you have dikes of a few meters high. And then — also which is just so striking — a busy train line going past it, roads etc, etc around it. And then you have this kind of semi-wildness that unfolds, in between this very densely populated area. And of course, in a very densely populated country, the Netherlands: 70 million people on about 40,000 square kilometers.
Koen Arts 04:53
The Oostvaardersplassen is a reserve unlike other natural areas in the Netherlands. It's rife with bird life, and sports a wild cast of characters, including lots of big mammals — which we'll meet later. Reminiscent of the Serengeti, but smaller. At least that's what the Dutch tell themselves.
Mendel Skulski 05:43
That's funny. I know that the Netherlands is pretty famous for like miniature... all sorts of things, right?
Toon Vos 05:48
Exactly. The tiny Serengeti.
Mendel Skulski 05:52
It's kind of quaint, how Canada with all this wide open space, we have towns that are super proud of their novelty largest thing in the world. And in the Netherlands, we have you know, this compact little country where everything gets miniaturized.
Toon Vos 06:06
We have tiny everything. We have a tiny theme park. The theme is tiny. And the natural areas are pretty tiny as well. This is big for Dutch standards.
Mendel Skulski 06:18
So this polder is the bottom of the ocean transformed into the Serengeti, of a sort.
Toon Vos 06:24
Yeah. And on its way to becoming the savanna it is today, this little polder was transformed more than once.
Adam Huggins 06:31
Can I ask a question really quick? This might be a dumb question. But why would you go to all the trouble of claiming agricultural land from the ocean? And then just decide to turn it into like a tiny wilderness?
Toon Vos 06:47
That's a good question.
Adam Huggins 06:49
Sounds like a lot of work.
Toon Vos 06:50
Well, it didn't start with that intention. If anything this nature reserve started off as an accident. When they first started to poldering process, the land was originally planned to be an industrial site. But it would turn out at the western edge was particularly difficult to lay dry.
Adam Huggins 07:05
What you're saying, just from my understanding, is that it never was particularly good for agricultural land because it was too wet — didn't do a good enough job claiming it from the ocean. And you can't dig ditches because you're already below sea level.
Toon Vos 07:19
Exactly. So the only way to lay it dry is to pump. So all kinds of efforts were made to speed up this process. Airplanes were used to sow reed, which act like little biological pumps pulling the water up and evaporating it — drying up the soil it grows on.
Toon Vos 07:37
But planting all those reeds had a side effects. In the late 70s. an ecologist by the name of Frans Vera noticed that the reeds were full of geese. Thousands of greylag geese, pausing on their treks from Siberia had taken to feasting on the stuff. And that's when Frans noticed something that was supposed to be impossible.
Toon Vos 07:58
And so began an experiment which fundamentally challenged the field of ecology and continues to influence the way we perceive and manage nature.
Adam Huggins 08:10
I might be awake by the time that the theme is over.
Introduction Voiceover 08:16
Broadcasting from the Low Countries of Europe, this is Future Ecologies — exploring the shape of our world through ecology, design and sound.
Frans Vera 09:04
My name is Frans Vera. I'm a biologist. But in my heart, I'm a nature conservationist.
Toon Vos 09:11
This is Frans Vera, the ecologist at the very beginning of this grand experiment. Fransalways enjoyed birdwatching. So when the word got around about this new hotspot for greylag geese and other avian sightings, he and the entire Dutch birding community were ecstatic. Many of them would drive out to the dikes alongside the Oostvaardersplassen. They wanted to enjoy the explosion of rare bird life while it lasted. In a couple of years, they thought, the reed would grow over the open water, and many birds would go elsewhere.
Frans Vera 09:47
Even after two years, three years, the whole was covered already with reed from three meters high! So nobody had any idea of how to preserve it. And that was the reason that among nature conservationists, an area like the Oostvaardersplassen was called a "throwaway biotope". So it would be interesting for about, let's say, a decade, and then it was finished.
Adam Huggins 10:18
So I understand from that quote, they planted reed to try to dry out the wetland. Instead, it made great habitat for geese. And they thought that that was only going to last for so long because the reed would initiate a kind of process of succession that would eventually get rid of the wetland like they had intended.
Toon Vos 10:35
Yeah, exactly. During his studies, Frans was taught about the process where different kinds of vegetation would follow each other in a linear fashion. As the reed was taking over in the Oostvaardersplassen, the soil would dry out and give way to other kinds of vegetation. Eventually, the marshy circumstances so cherished by many birds and birders will disappear. This theory is called succession theory.
Frans Vera 11:00
And the dominant theory at that time, in nature conservation, but in ecology as a whole, was the so-called succession theory. It was formulated in 1919 by the American, Clements. And the theory is that every time when you have a development, which started at bare soil like the polder, then you'll get a colonization of first small plants, then large plants and shrubs. And if the hydrology and climate is that trees can grow, the end is the climax forest. So that's, for instance, the idea that the whole of Europe but also the whole of Northern America, would have been originally covered with a closed canopy forest.
Toon Vos 11:53
So the theory goes, leave a bare patch of land alone. And after a succession of saplings and seedlings, shrubs and trees, a forest with a closed canopy will grow out of it. As the landscape changes, animals adjust to their new circumstances, and go wherever there's food or shelter.
Adam Huggins 12:11
I love that we're discussing succession theory here on our fourth season of Future Ecologies, now. It's a pretty fundamental concept in ecology that I think also for many people, is still very important, although obviously, it's become more complicated over time. But I've never I've never thought of succession with respect to like, what happens when you resurrect land from the ocean, right? Like that's a kind of bare soil circumstance that is unusual for most of us.
Toon Vos 12:37
It's the ultimate bare patch of land!
Adam Huggins 12:40
Absolutely, yeah, square one.
Toon Vos 12:41
But seeing the multitudes of geese at the Oostvaardersplassen, Frans noticed something.
Frans Vera 12:46
They opened up the reedbeds, and they did something of which everybody had thought it would be impossible: they were even able to change reedbed back into open water! And it struck me as an ecologist, because suddenly, I see that grazing animals steer the succession. Instead, what I learned at university: that animals always follow the succession. And because they ought to follow the succession, you end up in a climax situation, which is, in the temperate hemisphere, a closed canopy forest.
Toon Vos 13:27
The geese that had haphazardly arrived at this new patch of land were creating an ecosystem for themselves and for all kinds of other animals. At this place that was designated to become an industrial site, they were punching holes in the manmade reedbed — slowing down, and even reversing the process of succession everyone suspected.
Frans Vera 13:47
So you had the combination of shallow water and reed, which was a bird paradise for marsh birds: Harriers, geese, ducks, just name it. A lot of bird species, which were at that time very rare in the Netherlands, became very common in that area.
Toon Vos 14:06
So suddenly, there was a huge interest in keeping these marshy wetlands for all the new bird live in the area. But ironically, the marsh was threatened by the reeds that brought the geese in the first place. Mowing the reed manually would have been incredibly difficult and expensive. That's why people called the Oostvaardersplassen a throwaway biotope — it was impossible to sustain. But what actually happened is that the geese were taking care of the maintenance of the area.
Frans Vera 14:34
And here, the geese did it. And they proved to create the habitat for all kinds of other bird species.
Toon Vos 14:42
Instead of seeing the Oostvaardersplassen as a throwaway biotope, Frans and other biologists started to see it as something special in its own right. This explosion in biodiversity led to birdwatchers successfully petitioning for the Oostvaardersplassen to be protected as a new ecological reserve.
Frans Vera 14:59
We are always complaining and being sad about everything that is becoming lost.
Toon Vos 15:06
But instead of wallowing in despair, Frans was inspired by his colleague Ernst Poorter.
Frans Vera 15:12
He said "We have now a new polder. And you see, we can have new things, which are probably as valuable, as nice as beautiful as what we've lost".
Soundscape 15:30
[Train station announcement]
Toon Vos 15:31
I think it's time for me to show you what this is all about. Let's take the train from Brussels in Belgium — where I live — to Lelystad in the Netherlands — the country where I'm from.
Toon Vos 15:46
As we wait for the train to arrive in Lelystad, I'll get Frans to help us compare the two theories at play.
Toon Vos 15:53
If it's possible for a gaggle of geese to influence the succession of an ecosystem, Frans reasoned that large herbivores would be exceptional at it. We already recognize this intuitively with cultivated animals. Pastures don't turn into forests, and much of Scotland lacks trees because of its long history of sheep herding. But somehow, in the halls of academia, wild grazers had been set apart.
Frans Vera 16:19
If a domestic cow can create and preserve grassland, why not a wild cow, or a wild horse? "Nooooo," all the scientists says.
Frans Vera 16:31
"Why not?"
Frans Vera 16:32
"No, we had wild cows all over Europe, we had wild horses, we had European bison, we had moose, we had red deer..."
Toon Vos 16:41
But despite acknowledging the historical presence of all these different grazers, ecology textbooks said that, across all of Europe, humans were the only force keeping the climax forest at bay.
Toon Vos 16:54
That's the succession theory.
Toon Vos 16:56
To which Frans said,
Frans Vera 16:58
"That's a nice theory. I have another theory. Shall we test which theory is the good one?"
Adam Huggins 17:05
Said like a true scientist.
Toon Vos 17:07
And as it happened, France recognized that the thousands of geese that visited the Oostvaardersplassen needed both open water — to graze the reeds — and open grasslands — to rest during their molting period.
Frans Vera 17:21
So I said, you'll have to add an area of grasslands to the marshy area, because those two parts are complimentary for the functioning of the ecosystem as a whole. Because if we don't get it, the whole system will collapse.
Toon Vos 17:39
Artificially maintaining this marshy ecosystem would be an impossible task. But these hungry geese were offering to do it for free. So land managers needed a way to convince them to keep returning to the Oostvaardersplassen. That is, they needed to provide grasslands.
Frans Vera 17:57
My theory is if a cow can create grass, and then wild living oxen can do the same. So if you have wild oxen, you will have open grassland, which is very well for the geese.
Toon Vos 18:11
So Frans proposed an unusual way of creating grassland for the migratory geese of the Oostvaardersplassen: Could wild herbivores be used to create new habitats for other species in an existing nature reserve? This was the trial by fire — the start of the experiments that will put the Oostvaardersplassen on the map.
Frans Vera 18:31
And I got permission then from the ministry and also from a National Forestry Service to buy wild oxen and wild horses. So we had two breeds —
Toon Vos 18:41
These two breeds are called Heck cattle and Konik horses,
Frans Vera 18:45
Which were not common known as dairy cattle or as riding horses. So then they were brought into the area and it worked. It worked!
Frans Vera 19:02
A large area of grassland developed. So, what the animals did is they created their own biotope.
Soundscape 19:10
[Train intercom: Lelystad station]
Frans Vera 19:14
The classical theory: animals follow the succession. While my theory was animals drive the succession. Not all the animals, but the large herbivores. And they are essential in the functioning of ecosystems, and we just shut them out of the system.
Toon Vos 19:31
Frans realize that if large herbivores can steer the succession, what we imagined as natural — a dense, tree-laden forest — may have been the result of our removing the large grazers. Their absence allowed succession to proceed in a way that we now assume is inevitable. Meaning that the European forests of history may have looked fundamentally different than those that we know today.
Toon Vos 19:58
Here, Frans points to clues in the etymology of the modern word "forest", in a lecture from 2017.
Frans Vera 20:06
The word "foras" — Latin "foras": outside, without — as the origin of the word forestis, which we find in charters. We have charters going back to the sixth and seventh century, which were talking about a forestis, the origin of the word forest. And it had to do with Roman law. Roman law says what is outside the cultivated, and doesn't belong to anybody, belongs to the Emperor.
Toon Vos 20:33
In other words, the word forest doesn't refer to a place with many trees. It refers to a place that is uncultivated by people. And it wasn't the only word for a place without people
Frans Vera 20:45
And the wilderness and wild animals, they lived in what was deserted. That means uninhabited by people, and it was called the Desertum Regis — the Royal Desertum.
Toon Vos 21:00
What at one point was called "the Royal Desert" was also called the forest, both words referring to the same wild places. Over time, their meanings diverged. Until eventually, deserts were known to be hot and full of sand, and forests were places where trees blotted out sky. But Frans contended that so long as large herbivores roamed the forestis, their hooves and their teeth would have kept the wooded lands bright, open, and heterogenous and the Oostvaardersplassen will be the perfect case in points.
Toon Vos 21:02
Hallo hallo, goedemiddag [conversation continues in Dutch].
Toon Vos 21:48
This is ecologist Perry Cornelissen, who met me for a tour of the Oostvaardersplassen. After a coffee, we ventured into the natural reserve in a 4x4 from the Dutch Forestry Service.
Perry Cornelissen 22:06
We are now in front of the fence, the gate, where the area starts where the large herbivores graze and where people cannot go into. Alright, I will open the gate.
Toon Vos 22:26
This won't be the last time I have to cross a formal boundary to get into "the wild" for this episode. As we were driving into the Oostvaardersplassen, I noticed how many birds of prey were on the hunt. Normally, if you're lucky, while driving through the countryside, you might spot just one. But here, every couple of hundred meters, watchful eyes in the sky were scouring the ground for small rodents.
Perry Cornelissen 22:54
So now we are in the area where the large herbivores are. We have three different species: cattle, horses and red deer. And they were introduced in 1983. And we started with a population of 18 Heck cattle and 20 horses, Konik horses. And in 1992 also red deer were introduced and there were 40 of them.
Toon Vos 23:21
These populations weren't managed directly. They were kept in check by the food supply, especially in winter. Nonetheless, after 20 years, the number of these large grazers went from dozens to over 5000.
Perry Cornelissen 23:36
So now we're entering a large group of Heck cattle. What you also can see is that the great white egret is between the large herbivores because when the large herbivores graze, they disturb the fauna on the surface, so these great white egrets are waiting for maybe amphibians or voles to jump out of their holes and then they grab them.
Toon Vos 24:01
So they're hunting?
Perry Cornelissen 24:02
Yes.
Toon Vos 24:02
Amidst of the Heck cattle.
Perry Cornelissen 24:03
Yes.
Toon Vos 24:04
We can see how many would you say? About 100 cows?
Perry Cornelissen 24:08
Oh, this is a group of about, I think 60 or 70.
Toon Vos 24:12
And then about three, no, four, five, white great egrets are standing there.
Perry Cornelissen 24:20
There are more, some of them you can't see, because the vegetation is too high. But you can see some white spots everywhere. I think maybe 30 or 40 great white egrets in the in the vegetation we can't see.
Toon Vos 24:33
Before the Oostvaardersplassen became a natural reserve, the great white egret was practically non-existent in the Netherlands. And here we are, driving around the former bottom of the sea, looking at dozens of them.
Toon Vos 24:46
Right now, we are looking at a big bull and he's, what is he doing?
Perry Cornelissen 24:51
These bulls, they live in small bull groups in the area and we have about six of these bull groups. And in their territory, they have the sandpits they make. And right now one of these bulls is in his in sandpit and showing how strong he is by scraping soil with his hooves and throwing it in the air. And sometimes, they go with their horns into the sandpit and scraping with their horns in the soil. And just to show, look, I'm here the boss, I'm the biggest and strongest, don't mess with me.
Toon Vos 25:27
This was the first time I'd ever seen cows in the wild. Sure, they were put there by people for a specific purpose, but they didn't wear ear tags, pregnant cows weren't being milked by humans, and bulls apparently liked to dig sandpits. These weren't the farm cows I was used to. After we visited the Heck cattle, we took a left which led us to the other side of the train tracks, which go through the Oostvaardersplassen. Originally, the train line was planned to make its way straight through the natural reserve. But a compromise was reached after protests from the climate movement, sparked by a report written by Frans Vera. Incidentally, the Dutch political mode that relies so heavily on compromising is affectionately called "the polder model". It was decided that the train line would take a slight detour, dubbed "the bathtub route", because of its shape, to avoid the heart of the natural reserve. The other side of the tracks, Perry told me, was a piece of the reserve where grazers hadn't been allowed for decades. Effectively, it served as a control plot for Frans' theories about large herbivores. The landscape we entered was the opposite of the wide open plains we drove through moments earlier. Instead, it was a mini jungle named the Kotterbos.
Adam Huggins 26:52
Everything is tiny, as you said, in the Netherlands, you have a mini jungle. What does a mini jungle look like?
Toon Vos 26:57
So now we're driving into an area, much more vegetation, there's shrubs, there's trees of different kinds, we are driving along a narrow path in the middle of it all. And this is the Kotterbos, a really big difference from what we were just seeing. All of a sudden, we are in between trees and shrubs, and we can't see all that far. So compared to what we were just seeing, the open plains, this landscape is the complete opposite. You wouldn't be able to walk through here: there's nettles, there's reed, it probably wet too. So you'll you'll get wet feet. I feel like, yeah, like you'd need a machete to to make your way through.
Perry Cornelissen 27:44
In this landscape, you don't know what will happen within ten meters [adds something in Dutch].
Toon Vos 27:56
Here, perry adds in Dutch that it was always exciting to go into the Kotterbos, but it was also a relief to make it out in one piece.
Adam Huggins 28:03
It is a jungle. Oh my god.
Toon Vos 28:05
The dense and chaotic Kotterbos and the grassy plains of the Oostvaardersplassen are two alternate realities of the same place. Their stark differences show just how much impact large grazers can have on a landscape.
Mendel Skulski 28:21
When we come back, the views from the train prompt this experiment to take a turn.
Mendel Skulski 28:49
Welcome back, my name is Mendel. This is Adam.
Adam Huggins 28:52
Hey, still waking up.
Mendel Skulski 28:53
This is Toon.
Toon Vos 28:54
Hey.
Mendel Skulski 28:54
And you are listening to Future Ecologies, where Toon is taking us on a tour of the Oostvaardersplassen. The site of an experiment that uprooted the science of ecosystem succession.
Toon Vos 29:06
And the person behind that experiment is Dutch ecologist Frans Vera. He told me that the geese hadn't been the only indicators of a different natural history in Europe. Oak trees also have a story to tell.
Frans Vera 29:20
And a forester will say an oak needs to be, as a seedling, with its head in full daylight
Toon Vos 29:27
For an oak to grow into an adult tree, it needs space and light. Pollen records show that oaks have been around in Europe since around 10,000 BCE. But there's one problem here: oaks are not able to grow up in a closed canopy forest. It's too dark. They do much better in an open landscape, or something Frans called a "wood pasture", which consists of a mosaic of grasslands, shrubs and trees.
Frans Vera 29:53
The moment you remove the large herbivores from wood pastures, it becomes a closed canopy forest. So there are a lot of former wood pastures in Europe, which were declared as nature reserves, or as a national park. And as a consequence, all the large herbivores were kicked out because they damage the nature.
Toon Vos 30:19
And then what happened?
Frans Vera 30:21
All the oaks disappeared. No regeneration of oak. They need light! So they all became forests dominated, totally dominated, by shade tolerant species.
Toon Vos 30:37
Those open wood pastures are loved by many famous 19th century painters. Their paintings of these park-like landscapes remain as a record of a kind of nature that is hard to recognize today. Majestic oak trees amidst a patchwork of grasses, shrubs, rocks and copses of trees. They don't look like the forests I know at all. More than anything, these artists wanted to protect the places that they found so beautiful. If only they could keep painting them forever.
Frans Vera 31:10
However, the tragedy is: they didn't know what were the conditions of the wood pasture, the conditions for those beautiful oak trees they painted. They said: "No! Keep away from it!" And that's also an idea all over in the world. If you withdraw as men, nature rebounds back to her original state, which she doesn't. Because you have taken her limbs, you have taken her arms, you make them cripple, because you killed all the larger herbivores, and then you say, "walk again". Of course not.
Toon Vos 31:52
Ironically, by removing the large grazers from the landscape, the so-called "reserves artistiques", or artistic natural reserves, lost the trees that made them famous. According to Frans, the home of the oak was a landscape that we barely know anymore. The forests of the past were not endless collections of trees, but endless collections of biotopes alternating each other. Homes to mosses, that prefer to cool and humid shade under the tree canopy, but also to insects, scouring for flowers in the broad daylight. Large grazers for putting the brakes on succession. And similarly, their grazing was subject to a system of checks and balances too. For an oak to make it to adulthood, a lot needs to go according to plan. Its acorns need to be picked up by a jay, who will hide them, amongst other places, in thorny shrubs for later. Like in the brambles of species like blackthorn or hawthorn. There, the oak saplings are protected from large herbivores, while still receiving ample daylight. Thorny shrubs made sure that the grazers couldn't fully prevent regeneration.
Frans Vera 33:02
And in fact, those thorny species are natural barbed wire. So what every forester does now — getting barbed wire around the tree to protect — it was already in nature. But nobody sees it anymore!
Toon Vos 33:22
The experiment at the Oostvaardersplassen was all about seeing what would happen if large herbivores were introduced back into the mix, not to recreate the pictureque paintings of the past, but to find out how the landscape would change. But how it would play out in reality, that's a different story. Once again, here's Koen, the nature writer and researcher from the top of the episode,
Koen Arts 33:48
It started off as an ecological experiment. And it became a bit of a social experiment. So ecologically, there are super interesting things that have happened here, all kinds of interesting species that thrive on the kind of management that was there. So that part of the ecology, you could say has been a success. So we're talking about rewilding, maybe if you want to use that term, or a new wilderness with minimal human intervention. But the problems came slowly as non intervention also meant no population control. And what has happened over the years is that large grazers have proliferated. And this leads to a very difficult scene, sometimes in harsh winters, when there's a lack of food, and we see a lot of animals die. Now, of course, dying of animals is something that belongs, that's part and parcel of nature and of nature conservation. But usually in the Netherlands, when large amounts of animals die, we don't see that.
Toon Vos 34:53
Here, Koen refers to wild animals in the other bigger natural areas in the Netherlands, but his words are just as true for the agricultural industry. The Netherlands, a country of 17 million people, is a home to 3.8 million cows, 12 million pigs, and more than 100 million chickens, whose deaths are simply accepted as a part of our identity as an agricultural export country.
Adam Huggins 35:20
Can I go back and we maybe we just glossed over it, but like, you've created this small wilderness, right? First, it was just bare soil, you added plants, and then some of the animals invited themselves. And then you add grazers. And you're missing the large predators. Why were the large predators never added?
Toon Vos 35:41
Well, first of all, we didn't have them at the time. Now, the wolf came in from Germany, and has been around in the Netherlands and Belgium for for a while now, which is exciting. But at the time, they figured that large herbivores are controlled by food supply,
Adam Huggins 36:00
Which we would call bottom up control. But not top down control, which would be the predators.
Toon Vos 36:05
But Frans added to that, that those predators wouldn't have gone after the large cattle anyways. Now, of course, you can kind of look at the ecology of fear and what that will do to populations. But that's where they were at, at the time. Now, land managers say, it's only a matter of time before wolves make their way into the Oostvaardersplassen.
Adam Huggins 36:27
So what you're saying is that they both didn't have the predators at the time to include, and they also didn't think that they were necessary. Is that right?
Toon Vos 36:35
Yeah, that sounds about right. But what made the Oostvaardersplassen stand out, is that the animals that died there are simply visible, no longer concealed from the public eye.
Adam Huggins 36:47
Oh, people could see them from the trains going by?
Mendel Skulski 36:49
From the rim of the bathtub!
Koen Arts 36:52
So what happened is, we saw looking out over the area, we saw animals dying. And this was very painful in many different ways, not only just for the animals, but also for people who felt they had a connection with the animals. And it is very strange to think that there is a Konik horse on this side of the dike, which can't find any food. And you can see it's getting slimmer and slimmer to the point where it just can't really live anymore in a way it should, and it will die in winter. And then, 200 meters on the other side of dike, there's maybe a pony in a meadow, and it's being fed by its owner. And that is what we assume a fairly happy pony.
Toon Vos 37:33
Koen says that people in Western societies struggle when discussing death. Because of its taboo status, we tend to ignore it, until it's staring us in the face. For example, on social media,
Koen Arts 37:46
Where, for instance, an image of a dying horse could go viral very quickly, and would invite lots of people to comment on that.
Toon Vos 37:58
By 2017, it got to the point where activists began throwing bales of hay over the fences of the Oostvaardersplassen for the animals to eat. Dutch society couldn't make up its mind what to think about our so called wilderness and its management style of "less is more". The experiment that was all about our non-intervention for an indefinite amount of time, was cut short in 2018, starting with the culling of the large grazers down to about one-fifth of their original population.
Mendel Skulski 38:31
Down to one-fifth. Like culling 80%.
Adam Huggins 38:35
Wow, that's an incredibly dramatic intervention.
Toon Vos 38:38
Yeah, they're still working on it actually, they're not done.
Mendel Skulski 38:41
Oh my God.
Toon Vos 38:43
Leading up to the policy change, the Oostvaardersplassen was often in the news, and even being thought of is pretty controversial. Precisely because of its policy of non-intervention and the animals that were dying because of it. For Frans, and many others involved in the natural park, the growing unrest was frightening. They received threats, and were portrayed as sadistic animal killers.
Frans Vera 39:11
I got threats. I got death threats. They even threatened to kill my grandchildren, because, they said, you have to change your opinion about the Oostvaardersplassen publicly.
Toon Vos 39:23
Some people compared Frans to Nazi leaders like Hitler or Mengele. It was a dark time, and I could feel the impact it had on him during our conversation.
Toon Vos 39:33
But despite the mudslinging France work on large grazers was being applied more and more throughout the Netherlands, herbivores were being introduced or reintroduced in many places to become an integrated part of the ecosystem. But there would be a major difference with the Oostvaardersplassen. In other places, the grazing population would be tightly controlled by humans rather than food supply. Frans' grazers were in high demand throughout the Netherlands, but the most integral part of his theory — letting nature run its course — would be permanently sidelined in the favor of culling.
Toon Vos 40:11
I wanted to see how Frans' ideas were being applied elsewhere in the Netherlands. So I met up with science and biology journalist Gemma Venhuizen, who is the co-host of one of my favorite Dutch science podcasts "Onbehaarde Apen".
Toon Vos 40:26
Hello.
Gemma Venhuizen 40:26
Hi! [introductions in Dutch]
Toon Vos 40:29
In one episode, she mentioned that she used to be a volunteer as an assistant ranger at another Dutch nature reserve called Kraansvlak. We met up in the dunes of the North Sea on a very windy day. We were about to embark on a search for an animal I had never seen before. An animal that almost disappeared off the face of the earth in the early 20th century. But first, we needed to climb the electric wire that is supposed to keep the wilderness inside of this nature reserve. This is the Netherlands after all.
Adam Huggins 41:03
Can't let the wilderness out, God forbid!
Toon Vos 41:06
Well, we have to climb to get in?
Gemma Venhuizen 41:09
Yes, you have to get over the fence because of course, the European bison stay still live in an enclosure. Well, shall I?
Toon Vos 41:19
Yeah.
Gemma Venhuizen 41:19
Shall I go in first?
Toon Vos 41:20
Yeah you can go in first, we'll see if it's safe!
Toon Vos 41:25
European bison, or wisenten, as we say in Dutch, are the largest land-dwelling animals on the European continent. They are related to North American bison, but have a smaller hump on their back and they stand a bit higher on their feet. Sadly, they went extinct in the wild in 1919. After the ancient oxen and horses of Europe, known as aurochs and tarpans, another large herbivore bit the dust. Or did it?
Mendel Skulski 41:55
Or did it?!
Gemma Venhuizen 41:56
In 1929, they started with the reproduction program.
Toon Vos 42:02
breeding bison in captivity,
Gemma Venhuizen 42:03
and in 1952, in Białowieża, I hope I pronounced it correctly,
Toon Vos 42:09
a town in Poland known for its old growth forest,
Gemma Venhuizen 42:12
the first bison out of that program was reintroduced into nature. And then in 2007, so then the first bisons came here to the Netherlands.
Adam Huggins 42:24
I guess I'm just trying to picture this. So you snuck in past some electric wire to like a dune area, to see bison.
Toon Vos 42:35
Yeah.
Adam Huggins 42:35
Is that Is that right? What are we looking at here?
Toon Vos 42:37
That's right. I mean, it's funny, you should talk about pictures, because they actually have a beautiful website with very carefully curated pictures. The Dutch are very proud of their bison. Also, we didn't sneak past the electric wire. No, no, no, there was a neat plaque that explained us the ground rules.
Adam Huggins 42:55
I see. Oh, my God. Okay, I'm looking at pictures of them right now.
Toon Vos 42:59
Did you find it, the Dutch website?
Adam Huggins 43:01
Yes. This is a bunch of bison out on on like, a bunch of sand. You know, you were talking about the desert earlier. Looks a little bit like that.
Toon Vos 43:09
What you can't see on the picture is that the Formula One track is right next to it.
Adam Huggins 43:15
Everything is tiny.
Toon Vos 43:16
Everything is tiny. And one thing I think is really interesting about the Kraansvlak in comparison to the Oostvaardersplassen, is that it's here that Frans' theories about large herbivores get applied to an epic narrative about a species brought back from the brink of extinction. And this story of resurrection would prove to resonate deeply with the Dutch public.
Adam Huggins 43:39
It's certainly a lot sexier than watching horses die from the train.
Toon Vos 43:44
Following a similar logic as the large grazers in the Oostvaardersplassen, the European bison were introduced to help maintain the coastal landscape and put the brakes on succession. Gemma and I looked long and hard to see if we could spot them.
Toon Vos 43:59
Haha! [excited murmuring]
Gemma Venhuizen 44:01
Oh, wait.
Toon Vos 44:03
Are we seeing bison or cows?
Gemma Venhuizen 44:04
Yeah, well, first I thought it was. Oh, this is kind of a deception. And I'm also kind of ashamed because I was like, having this exclamation like, Oh, we're seeing them! But now I have a closer look, these are just the Scottish Highlanders.
Toon Vos 44:22
No luck finding European bison in the dunes this time. Quite a disappointment after scrolling through all those photos on the Kraansvlak website in anticipation. These animals have become icons of untamed nature in the Dutch consciousness. It is striking how these large herbivores are loved and celebrated, delicately managed, so we only see their best side. Their population is controlled —
Adam Huggins 44:47
Right, so you're not gonna accidentally come across one starving to death on the side of the train tracks or anything like that.
Toon Vos 44:54
No, you're not. In the Netherlands, every patch of nature comes with a list somewhere, telling managers how big the population should be. No herbivore lives in our country without our permission. And when you enter the Kraansvlak reserve, there is a sign that lays down the ground rules: "Keep your distance from the animals and stay on the path!" Are these the ground rules to all of nature in the Netherlands?
Toon Vos 45:22
As the poet JC Bloem once said: "Wat is natuur nog in dit land?" What is nature in his country, anyway?
Toon Vos 45:32
Koen says that although only small chunks of the Netherlands are reserved for nature, the Dutch public have generally been enthusiastic about this so-called rewilding. This has resulted in large symbolic accomplishments, like reintroducing European bison as a steward of the dunes. But for Koen, the future of nature conservation starts much smaller.
Adam Huggins 45:55
Smaller. Of course, it does. This is the Netherlands!
Toon Vos 45:58
Yeah, exactly. Not only do we put physical fences between humans and nature, but we fence ourselves off conceptually as well. After all, the forestis was defined as wherever humans aren't. Koen wrote a book about his own experiment that he did with his wife, Gina, in an attempt to begin to tear down these fences in their own lives. At the time, they were both working in the field of nature conservation, but were mostly stuck behind their desks, inside. So, they decided to have a Wild Jaar — a "wild year".
Koen Arts 46:38
A Wild Year for us was trying to reconnect with nature, but not by going abroad going to the woods of Canada or Alaska or, you know, going on Expedition for a year. No, a Wild Year was for us, trying to find wildness in a land without wilderness. So we set one simple rule: we said "Okay, can we spend more time outside and inside on a daily basis?" Which, you know, clearly means at least 12 hours on average. And we also said "We should do this in every season of the year"
Toon Vos 47:11
Koen and Gina didn't want to disengage from their everyday lives, or turn their back on society. They wanted to spend lots of time outside while living their life as they would have otherwise. And so they started camping in Koen's parents' backyard in autumn, and managed to spend more time outside than inside for more than a year — as a way to reconnect with nature.
Koen Arts 47:35
So if you think of nature conservation as a thing that you do from a managerial point of view, and this is in essence, what we see in the Netherlands and many other countries — it's... it's a technical thing. But for me, it starts with a fascination for nature, human fascination, and a sense... an ethical sense that we need to protect biodiversity; we need to protect species; we need to have areas still, that are essentially non human, you know, where our natural autonomy, or the self will of land, of animals, of plants is present
Toon Vos 48:14
Koen and Gina's wild year affirms that you can find wildness in a country without wilderness. Their experience reminded them of why they got into the field of nature conservation in the first place, and drove home the point that experiencing nature in any way you can, makes you feel more passionate about caring for it.
Adam Huggins 48:36
You know, Toon, you brought up the term "rewilding" earlier, which I think is commonly used in Europe, you know, instead of the term "restoration" or something like that, right? Rewilding.
Adam Huggins 48:49
And it strikes me from the experience of this couple that we've been talking about rewilding as something that we do to the land right? We, like, rewild this polder, we rewild the section of land, and then you know, we fence it off to keep keep the wilderness inside, right? And it strikes me that this couple, it's like they're... they're experimenting with rewilding themselves. Maybe rewilding is not something that we do to the land right, but something that we participate in?
Toon Vos 49:16
Yeah, I think Koen would agree in the sense that he says that it's mindset first.
Koen Arts 49:20
By and large, nature for us is something that is away from us. And those demarcations are super strong in the Netherlands.
Toon Vos 49:30
After meeting Koen I downloaded a time tracker on my phone to find out just how much time I spent outside. Turns out that it's not really close to 50% per day. Even though we have never met in person, Adam and Mendel, what percentage of my time would you guess I spent outside of the past three months?
Adam Huggins 49:49
You look outgoing and outdoorsy... um what about 20%?
Adam Huggins 49:55
20%. Mendel?
Mendel Skulski 49:57
I think you might be a little bit more like me that you spend a lot of time I'm thinking about nature, but in reality, you're inside working. I'm going to go with 12%.
Toon Vos 50:10
Fair. More like 7%
Mendel Skulski 50:13
Oh, wow. I'm afraid to try to figure this out for myself.
Toon Vos 50:19
And I too consider myself a fairly outdoorsy person who goes for walks a lot and goes to places in the weekends that are outside.
Mendel Skulski 50:28
Oh my god, I think it'd be sobering if I actually tried to clock all my outdoor hours. Embarrassing even.
Adam Huggins 50:35
We could try it for the next couple of weeks, Mendel.
Toon Vos 50:37
It's a pretty fun experience, because once you become aware of it, you will take the outdoorsy option more often. And this was also something that happened when I interviewed Koen. He's like "you want to do the interview outside?"
Mendel Skulski 50:53
{Laughs]
Toon Vos 50:54
And I just hadn't... I hadn't prepared for it. But I should have known — this guy wrote a book about it, you know?
Toon Vos 51:03
Letting nature go its own way in the Oostvaardersplassen sounds very not Dutch to me. The nature that I encountered while I was growing up was always tidy and organized. My family and I used to visit the same camping site every year. Between the different fields, where visitors would pitch a tent or set up their camper van, were little patches of woodlands. In the middle of them, the owner of the campsite installed what he called "animal highways": long snaking heaps of tree branches and trimmings for rodents and other animals to seek refuge in. His animal highways were an imitation of the inherent chaos in nature. But using whatever was left of the woodland maintenance done to keep things organized and neat.
Toon Vos 51:57
With this, in the back of my mind, it seems like the Oostvaardersplassen was ahead of its time. It seemed like a small miracle that the Dutch government was willing to give it a shot in the first place. But there was a lot of pressure for things to go well. The Oostvaardersplassen needed to do everything just right. It needed to please every side of the debate.
Toon Vos 52:20
Many had hoped that putting large grazers on the landscape would create a mosaic — a patchwork of biotopes: the park-like landscapes of Europe's past. But, perhaps because of the lack of predators, or the lack of political will to create green corridors with other nature reserves, we instead got a savannah.
Toon Vos 52:43
Yet, the ripples of the Oostvaardersplassen have been felt outside of the Netherlands. In the UK, Isabella Tree and Charlie Burrell had inherited Knepp estate: a castle, a large piece of agricultural land, and the farming business that went along with it. No matter what they tried, traditional farming at Knepp was losing money year after year. They wanted a way out. And so they got in touch with Frans in the early 2000s.
Frans Vera 53:14
And then they decided we are going to rewild Knepp castle. So they stopped agriculture. And they had a tremendous development. It's now the hotspot for nightingales. It's the hotspot for the Emperor butterfly. It's the hotspot for all kinds of bird species, which are everywhere in United Kingdom, though going down.
Toon Vos 53:38
It's important to mention here that the population of grazers at Knepp is being managed. Excess animals are culled and sold as wild range meat. The meat selling endeavors are an integral part of their business model. Still, the project is seen as controversial: a subversion of their neighbors' well-maintained farmlands. Some see unpredictable chaos. Others see a kind of magic in its dynamism.
Toon Vos 54:11
Isabella Tree wrote a book, Wilding, about their journey rewilding Knepp. She quotes Frans saying "Open up the box, allow natural processes to develop, give species a wider scope to express themselves and you get a very different picture. This is what the Oostvaardersplassen is all about — minimal intervention, letting nature reveal herself. And the result is an environment we know nothing about."
Toon Vos 54:46
So where does this leave us? How can we protect an environment we know nothing about? As those dreamy 19th century painters showed, loving something is not the same as taking good care of it. Their static utopia was doomed by their refusal to accept it as a dynamic system. There's truth in the saying that if you love something, let it go. Only when you dare to release your hold, when you truly accept other beings as being their own selves, will a relationship begin to flourish.
Toon Vos 55:27
As contentious as the Oostvaardersplassen is, I feel like the experiment has been successful in many different ways. Looking at the large grazers now populating natural reserves in the Netherlands, messy nature becoming more widely accepted, and Knepp estate, whose business is thriving around their rewilding projects, it's clear to me that this bold experiment has shaken up the field of nature conservation. It showed the potential of spaces dismissed as throwaway biotopes — that even the former bottom of the sea can develop itself into a sprawling haven for wildlife. That amidst all of the destruction, new things can and do emerge.
Mendel Skulski 56:29
Next time on Future Ecologies, we're jumping back across the pond: exploring the very different lineage of wildlife and wilderness in North America, where space is plentiful, and colonization is in the not so distant past.
Toon Vos 56:47
This episode was produced by me, Toon Vos.
Mendel Skulski 56:51
And me Mendel Skulski.
Toon Vos 56:53
With help from Adam Huggins and Lili Li.
Mendel Skulski 56:57
Future Ecologies is an independent production made possible by our supporters on Patreon. You can help us tell more stories from more places by supporting the show at patreon.com/future ecologies.
Toon Vos 57:13
If financial support isn't for you, then you can still help the show in a very important way. Share it with your community and leave a rating or review wherever you listen. It makes a huge difference.
Mendel Skulski 57:26
For photos from Toon's adventures, citations, transcripts, and more, visit us at futureecologies.net
Mendel Skulski 57:36
Toon and I also wrote a different version of this story for Are We Europe magazine. You can catch that in Issue #15: The Lie of the Land.
Toon Vos 57:46
This episode featured the voices of Koen Arts, Frans Vera, Perry Cornelissen, and Gemma Venhuizen.
Mendel Skulski 57:55
And with music by Francesca Vincentie, Museum of No Art, César Franck, Vincent van Haaff, and Sunfish Moon Light
Toon Vos 58:06
Special thanks to Penny Green, Isabella Tree, Charlie Burrell, and Gina Maffey.
Mendel Skulski 58:13
You can reach us on twitter, facebook, and instagram, @futureecologies, or get in touch through our website — futureecologies.net
Toon Vos 58:25
Okay, is that it?
Mendel Skulski 58:27
That's it. Have fun outside.