The Ruin And Redemption Of The American Prairie

Tallgrass prairies in the United States were cleared for industrial farms. Can the lost biodiversity be restored?

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• 0:00Speaker 00

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• 0:37Ira Flatow?

  Science Friday is supported by MathWorks, creator of MATLAB and Simulink software for technical computing and model-based design. MathWorks: Accelerating the pace of discovery in engineering and science. Learn more at MathWorks.com. Hi, I'm Ira Flatow. You're listening to Science Friday.

• 1:01Ira Flatow?

  Did you know that most of the American prairie has been replaced by farmland? Well, what exactly have we lost?

• 1:08Speaker 02

  We're destroying it about as fast as we're destroying the Amazon rainforest. It's an environmental catastrophe, but nobody's paying attention.

• 1:21Ira Flatow?

  Perhaps you remember the 1971 film The Immigrants, nominated for five Academy Awards. I bring this up because there's a scene at the end of the film that has stuck with me for over 50 years. The story is about a family of Swedish immigrants who have arrived in Minnesota with grass-filled prairies as far as the eye can see. The farmer, played by the iconic actor Max Von Sydow, is searching for the perfect plot for his family farm. He walks for miles, through woods and streams, and finally sinks a rod into the ground, only to see that the dark, rich topsoil goes down more than two feet.

• 2:04Ira Flatow?

  He carves his name into a nearby tree, falls asleep underneath with a smile on his face. Now, I'm reminded of this iconic scene because today, the fertile American prairie might just be the most underappreciated landscape in the United States. Beginning in the early 1800s, the majority of these grasslands were converted into big industrial farms. Those rich, deep, dark soils, well, they're mostly gone, along with many of the birds, the bees, the bison, and an ecosystem that has vanished and been transformed over the centuries. My next guests have detailed the loss of biodiversity in the American prairie and those

• 2:48Ira Flatow?

  working to restore what remains. Let me introduce them. David Hoggie and Josephine Marcotti are longtime environmental reporters and the authors of Sea of Grass: The Conquest, Ruin, and Redemption of Nature on the American Prairie. They're based in the Twin Cities, St. Paul and Minneapolis, Minnesota. Both of you, welcome to Science Friday.

• 3:09Speaker 02

  Hi, Ira. Thanks, Ira. Delighted to be here.

• 3:13Ira Flatow?

  Do you remember that scene in the film? Did you see that film?

• 3:16Speaker 02

  I do remember that scene, and what I remember is that Carl Oscar's wife, the great Lou Vomel, is homesick. She keeps wanting to go back to Sweden, but Carl Oscar has fallen in love with the prairie and thinks he can become a millionaire farmer out here in this fertile, fertile land.

• 3:35Ira Flatow?

  All right, let's start at the very beginning. What makes a prairie a prairie? What is the definition of a prairie?

• 3:41Speaker 02

  The word you want to remember is it's dry. You have the Rocky Mountains on the west, which, when rain, storms, clouds move in off the Pacific Ocean, they collide with the western front of the Rocky Mountains, and very little moisture gets over the mountains onto the plains and prairies beyond. It's a little more wet in the east states like Illinois, Indiana, and it gets drier and drier as you get into Montana and Wyoming, close to the mountains. And very few plants can survive or thrive on that little rain. It's a bitter, hostile climate. It's 100 degrees in the summer, it's 30 degrees below zero in the winter.

• 4:25Speaker 02

  And the one plant that is perfectly suited for this hostile climate is grasses. They have deep roots, they're used to dry weather, they survive wildfires. And so it became the sea of grass.

• 4:40Speaker 03

  So, but the other thing that makes the prairie so interesting is that in the West, where it's very dry, all the grasses are very short and they're more sparsely scattered across, across the ground. But the further east you get, the more rain you get. And so, you know, 150 years ago, the Tall Grass Prairie was so tall that people couldn't stand or see over the grasses and they had to stand on the backs of their horses to actually see where they were going. So, and that difference is really just about wetness and rainfall.

• 5:10Ira Flatow?

  I learned in reading the book that, that less than 1% of the Tall Grass Prairie is left. How did this happen? Give us a brief history here.

• 5:21Speaker 03

  The Tall Grass Prairie is where there was enough rainfall and enough rich soil for European settlers to come in and turn it into agricultural land. And if you recall, this was, you know, a time of a huge population push across the continent of the United States. But this was the genesis of the American dream, where you could take your family, like the immigrants did in the movie, and move to a place and set down your stake and start farming and become wealthy. And many people did do that.

• 5:51Speaker 02

  The result is that frontier colonial farmers plowed up 300 million acres in less than a century. That's one-sixth of the continent was converted from this wild, unkempt prairie of grass and flowers into a tidy gridwork of a highly productive farm.

• 6:16Ira Flatow?

  And now the remaining prairie further west? That's getting uprooted too?

• 6:21Speaker 02

  When we talk about the short grass prairie, this would be states like Montana, Wyoming, western South Dakota. And what happens is that the plows sort of stopped around 1900, 1920, stopped at about the 98th Meridian, which is eastern Kansas, western Minnesota. And most of the colonial sort of settlers on the frontier decided that it was just too dry to grow the crops that they wanted to, corn and wheat. And so it became cattle country. You think about Montana, Kansas, because the only thing that would grow there was short grass. And so for better and for worse, by that quirk of history, the western prairie remained in grass after the tall grass prairie was plowed up. And what happened

• 7:06Speaker 02

  about 20, 30 years ago is that the seed companies and chemical companies started introducing seed hybrids and fertilizers and pesticides that enabled farmers to plant those crops, soybeans, corn, wheat, farther west.

• 7:23Ira Flatow?

  Wow. And of course, they then mix that in with all the fertilizer they throw on. That gets washed away too, right?

• 7:30Speaker 03

  Yes. So fertilizer is what they call a slippery element. It's very difficult to apply the right amount of fertilizer that a plant needs. And so what happens is that the excess fertilizer becomes dissolved in water, either groundwater or surface water. And then you have nutrients in the lakes and streams, and that can change the ecosystem entirely, and it also pollutes the water for, for drinking. And that is also the reason why we have a dead zone in the Gulf of Mexico is because all the fertilizer throughout the Mississippi Basin, all the excess fertilizer gets washed out of the soils and into the streams. It all ends up in the Mississippi River, where it flows down and out into the

• 8:12Speaker 03

  Gulf near New Orleans, where it can create a dead zone where nothing can live because of the excess nutrients.

• 8:19Speaker 02

  A lot of people are surprised when we talk about this, but the EPA, U.S. Environmental Protection Agency, has said that agriculture is now the number one source of pollution in the nation's rivers and a leading source of pollution in the nation's lakes. Even here in Minnesota, the land of 10,000 lakes, there are counties where there's not one lake that's safe for children to go swimming because they're polluted with nutrients and algae and so on.

• 8:48Ira Flatow?

  That's amazing. Let's move from lakes, which are some of my favorite subjects, to insects. I mean, the Midwest is known for staple crops like corn and wheat and soybeans, as you mentioned. But you visited Josephine Watermelon Farms in southwestern Indiana to understand the decline of the insect population. Tell us about what you learned there.

• 9:10Speaker 03

  So the food that we eat comes from crops that has to be pollinated by insects. Field corn is wind pollinated, and soybeans, they self-pollinate. So it's really the food that we eat, like watermelon or cantaloupe or vegetables and fruit, that need insects for pollination. And decades ago, people who grew those crops could just rely on the natural processes that insects and flowers have been doing for millions of years to create food. But over time, as corn and soybeans became the dominant crop across the Midwest, the pesticides and the lack of diversity in plants has greatly reduced the wild insects that we have.

• 9:54Speaker 03

  So the monarchs, the wild bees, flies, all the insects that you can think of that pollinate sort of gradually declined. So now we have places like southwest Indiana, where they grow watermelons and cantaloupe and squash, where they need insects to pollinate the crops. But they're what they call a sea of corn and soybeans, where there are very few places for insects to live. So as a result, over the last two decades or so, they began hiring beekeepers to come in with their domesticated honeybees to pollinate crops. And that has become an industry in and of itself.

• 10:32Ira Flatow?

  After the break, is it too late to save the American prairie?

• 10:36Speaker 03

  Only a few things could make a big difference in protecting the grasslands that we have.

• 10:47Speaker 04

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• 12:17Speaker 04

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• 12:30Ira Flatow?

  Dave, we're all aware of the iconic bison of the American West, once vastly covering, but also on the verge of extinction a century ago. Tell us what their role, what's their niche in the prairie ecosystem?

• 12:49Speaker 02

  Well, as your listeners will know, bison became almost extinct. Teddy Roosevelt commissioned naturalists to go west about 1900, and they could count only 20 or 30 bison left on the Great Plains after there had been a population of 20 or 30 million. The reason why bison are important today is that bison and grasslands evolved together over thousands of years. And grass needs ungulates like bison to grow well. Bison move around the land, they crop the grass short, which stimulates further growth. They fertilize the grass with their droppings. They spread seeds as they migrate across the land.

• 13:33Speaker 02

  They attract other creatures, prairie dogs and birds, that are all good for the grasslands. What happened is that bison are safe from extinction now. There are many thousands, but as Josephine writes in the book, most of them are raised as livestock. They're raised on ranches and corrals and sent to stockyards to be slaughtered for meat. The cool new movement that we found that's happening today is returning bison to the land in a semi-wild setting. In addition, there are now 30 or 40 Native American reservations that have tribal herds. That's spreading rapidly. They're taking these magnificent bison from Yellowstone National Park and establishing tribal bison herds.

• 14:18Speaker 02

  And that's a triple win. It's saving bison as a wild species. It's restoring the grasslands. And on the reservations, it's restoring and rescuing this endangered Native American culture of the plains tribes, the history, the rituals, the religion. It's just a magnificent trend that's taking off in the northern Great Plains.

• 14:40Ira Flatow?

  That is cool. Let's talk about something else that we often hear about, and that was the birds, right? The birds that live there. Give us an idea about what the state of the birds are. And I want to play first one of the most iconic sounds of the prairie in the western meadow lark.

• 15:06Ira Flatow?

  Boy, that is so soothing.

• 15:09Speaker 03

  I know.

• 15:10Ira Flatow?

  Isn't it?

• 15:11Speaker 03

  You can hear them talking to each other, yeah.

• 15:13Speaker 02

  It's so, it's so beautiful. You know, people ask, why did we fall in love with the prairie? It's so barren and empty and bleak. And the first thing that I always notice when we're driving out on reporting trips, you step out of the car and you just hear this chorus of songbirds. It's meadowlarks and bobolinks and finches and warblers, red-winged blackbirds. The bird song is just beautiful out there.

• 15:42Speaker 03

  It's funny that people who work in grasslands, they, they talk about LBJs, which is little brown job, you know, which is the common bird you see there as an, as a little brown job because they're, they tend to disappear into the grass. But they all have lovely songs. But what's, what is shocking though, is that the state of the bird report came out recently, which was a report by a number of conservation groups. And one of the biggest declines since 1970 has been grassland birds. Forty-three percent decline in grassland birds just since 1970. That's when I was in high school. I mean, it just in my, my lifetime.

• 16:17Ira Flatow?

  Is this, is this silent spring all over again?

• 16:20Speaker 03

  People have said so, but you know, it's really, it's not as hopeless as, as we're making it sound. Only a few, a few things could make a big difference in protecting the grasslands that we have.

• 16:32Speaker 02

  There's a great researcher in Iowa, Lisa Schulte-Moore, with her Strips Project. And she showed that if you just took 10% of cultivated farmland in Iowa and converted it to prairie strips or buffer strips, grassy strips, at the edge of a field where they catch the fertilizer, they catch the other farm chemicals and they stop erosion before all that can get dumped into the creeks. And as Josephine said, you know, it doesn't take a lot of change. We met outstanding ranchers in South Dakota and Montana who made modest changes to their grazing practices. They adopted something that's called rotational grazing, where you move the cattle to mimic the way bison used to move naturally.

• 17:17Speaker 02

  And with very modest changes on those cattle ranches, you see the grass coming back healthier and more diverse. You see songbirds coming back on those ranches. You see the full range of prairie wildlife starting to return. So rather modest changes can make a huge change, whether it's water pollution, climate change, wildlife preservation.

• 17:43Speaker 03

  So we have a chapter in the book about an organization in Iowa called Practical Farmers of Iowa. And this is a farmer-led educational program where farmers teach each other practices to preserve the soil. I mean, they know that they have a resource that cannot be replaced.

• 18:00Ira Flatow?

  It's a carbon sink also, isn't the soil, preserves carbon.

• 18:05Speaker 02

  The world's soils are the largest single carbon sink on earth. And people in the Midwest know this. If you go out to dig your garden, you sink your shovel and turn over a shovel full of soil out here. It's black, it's inky black. And the reason is it's full of carbon. Grasses have been sequestering carbon in that soil for thousands of years, which makes it extremely rich and fertile and wonderful. But it also means that if you plow it open, you're releasing carbon into the atmosphere and you're making climate change worse.

• 18:40Speaker 03

  And that is an ongoing problem because we're still losing a million acres a year of grassland to cropland.

• 18:46Ira Flatow?

  A million acres. Do you feel then with these losses versus with some farmers who are adopting different habits? Do you feel hopeful that you're going to regain what we've lost or at least stop it from losing it?

• 19:01Speaker 02

  I'd say a little bit of each, Ira. We're destroying it about as fast as we're destroying the Amazon rainforest. It's an environmental catastrophe, but nobody's paying attention. So that struck a note of urgency and alarm with us. But the more time we spent out there talking to farmers and ranchers, the more we came across these remarkably encouraging stories.

• 19:23Speaker 03

  We were talking about this when we were writing the book and trying to answer that very question. And what we came away with was this idea that there are 1,000 points of disconnected lights out there, that of people all over the country, all over the Midwest and the West, doing something on the land. And it's hard to measure the overall impact of that so far.

• 19:41Ira Flatow?

  And I want to thank you for your book and for your work and everything that you've been doing.

• 19:46Speaker 03

  Thank you, Ira.

• 19:47Speaker 02

  Thanks, Ira. Really nice talking with you. Thanks.

• 19:50Ira Flatow?

  Dave Hoggie and Josephine Marcotti are environmental reporters and the authors of Sea of Grass: The Conquest, Ruin, and Redemption of Nature on the American Prairie. They're based in St. Paul and Minneapolis, Minnesota, respectively. One thing before we go. Next Tuesday, June 17th, we're going live from the ocean floor, and you can come along with us. It's a live stream event. You'll get to explore the deepest part of the ocean, the Mariana Trench. And you can ask the crew of a deep sea research vessel questions about their work. If you want to come along, go to sciencefriday.com/ oceansmonth to learn more and sign up for the adventure.

• 20:35Ira Flatow?

  That's sciencefriday.com/ oceansmonth. That's about all the time we have for now. A lot of people helped make this show happen. Dee Petersman. Praise Aguchi.

• 20:50Speaker 04

  Kathleen Davis.

• 20:51Ira Flatow?

  Santiago Flores. I'm Ira Flatow. Thanks for listening.