Science Friday - Dwarf Tomatoes, Saguaro Cactus, Sonoran Desert. June 2, 2023, Part 2

Episode Date: June 2, 2023

Tomato Breeding Project Fueled By Over 1,000 Backyard Gardeners In 2005, gardeners Craig LeHouiller and Patrina Nuske-Small created the Dwarf Tomato Project. They wanted to preserve the flavor and beauty of heirloom tomatoes, without taking up too much space. They started crossbreeding heirloom tomatoes with smaller dwarf tomato plants. To do so, they enlisted volunteers from all over the world. Over 1,000 people have participated so far. You can even buy the seeds and plant them in your own garden! Ira talks with the project’s co-founder, gardener and author, Craig LeHoullier, based in Hendersonville, North Carolina.   Southwestern States Break The Dam On Water Stalemate Southwestern states have been aware for decades that their use of Colorado River water is not sustainable. Forty million people depend on the watershed across seven states, several tribes, and northern Mexico. After intense pressure from the federal government, Arizona, California, and Nevada presented a plan last month to cut water use in these states. While the proposal isn’t final, it’s an important step in a long stalemate among southwestern states hesitant to use less water. The three states propose cutting 3 million acre-feet in water use through 2026—about ten percent of their total water allocation. The federal government plans to spend $1.2 billion to pay water users for the cuts. Joining Ira to break down what this plan means for southwest states is Dr. Sharon Megdal, director of the University of Arizona’s Water Resources Research Center in Tucson, and Luke Runyon, managing editor and reporter for KUNC, in Grand Junction, Colorado.   Tracking The Saguaro Cacti Decline One of the most iconic symbols of the American Southwest is the saguaro cactus—the big, towering cactus with branching arms. Saguaro are the most studied variety of cactus, yet there’s still much we don’t know about them. Once a decade, researchers from the University of Arizona survey plots of roughly 4,500 saguaro to assess the health of the species. This past year there was a record low number of new cacti growing—the fewest since they started decadal surveys in 1964. What’s driving this decline? Ira talks about the state of saguaro cacti with Peter Breslin, postdoctoral researcher at the University of Arizona’s Desert Laboratory on Tumamoc Hill, based in Tucson, Arizona.   These Conservation Scientists Are Keeping The Sonoran Desert Diverse Many Americans might be surprised just how expansive and diverse the Sonoran Desert actually is. The 100,000 square-mile desert stretches across the border between the U.S. and Mexico, with the northernmost regions in southern California and Arizona making up just one third of the desert. The sweeping terrain is home to thousands of plant and animal species and contains every existing biome in the world—from timber tundras to rolling grasslands to arid desert basins. The majority of the Sonoran is within the Baja California peninsula and the Mexican state of Sonora, which includes the Gulf of California. The gulf alone is teeming with life—famed ocean explorer Jacques Cousteau once called the desert, “the world’s aquarium.” Ira talks about the rich biodiversity of the Sonoran Desert and the importance of scientific collaboration across the border with Ben Wilder, director and co-founder of Next Generation Sonoran Desert Researchers, and Michelle María Early Capistrán, a conservation fellow at Stanford University and board member of the Next Generation of Sonoran Desert Researchers.   To stay updated on all-things-science, sign up for Science Friday's newsletters. Transcripts for each segment will be available the week after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

This is Science Friday. I'm Ira Flato. Later in the hour, what the Colorado River deal means for Western States and for the river, plus the challenges facing the iconic Suaro cactus in the Sonoran Desert, and how the Gulf of California is a vital part of this vast desert ecosystem. But first, my favorite time of the year is here, tomato season. Now, here in the Northeast, the ground has warmed up enough to plant those tomatoes. And you know what happens if you plant tomatoes, right? You know that the vines get to be really leggy. You have to find creative ways of wrangling these eight-foot-long monsters. So this year, as I was planting my garden, I was delighted to come across a project that combines my love of gardening and doing science in my backyard and a solution

to this vine challenge. It's called the Dwarf Tomato Project and was started in 2005 by two gardeners, Greg Lhuliere and Petrinanusk Small. They decided to cross-breed heirloom tomatoes with smaller dwarf tomato plants, keeping that tasty tomato flavor of heirlooms, but taking up a lot less space in the garden. And they enlisted volunteers from all over the world to help them to grow these. Over a thousand people have participated so far. And I want to really get into this with Craig. Craig is here. He's a Gardner, an author of the 2014 book, Epic Tomatoes. He joins us from Hendersonville, North Carolina. Welcome to Science Friday. Oh, thank you so much, Ira. It is an absolute delight to be here. You're welcome. Okay. Let's start with the basics. What is a dwarf tomato compared to a standard

variety? Dwarf tomatoes are very much lesser-known genetic type of tomato. Indeterminants are the unruly children of the garden that go up and out and they need to be contained. Determinants, a lot of people know about them if they've grown Roma. What dwarfs are a somewhat obscure variety that the genetics gives them a very thick central stem and a very beautiful, crinkly dark blue-green foliage, as well as a characteristic where they grow upward at about half of the rate of the indeterminate types. And so an eight-foot Cherokee purple will be a four-foot dwarf by the end of the season. Oh, love it.

I know. And the useless tomato cage is perfect for the dwarfs. And the tomatoes, are they smaller, too, or are they normal size? Well, of our 150 types and counting, we have everything from small cherries up to one to one-and-a-quarter pound fruit. Every color you can imagine, we have those that are tart, those that are sweet. those that are intensely flavored. And running this project with Petrina in the last, gosh, 18 years, which is a hard thing to even conceive of, has been the most fun I have ever had during

my 40 years of gardening. Tell us about that. How did you come up with the idea for the Dwarf Tomato Project? And why do you call it a project? Sure. Well, you pretty much said why we came up with it. When we were selling seedlings in Raleigh, the most frequently asked question is, what do you have great that taste incredible, but I can grow it in a pot. I don't have to climb a ladder. I don't have to take out my whip and tame the thing. And the answer in 2004 was a few things, but not a heck of a lot. So this was a niche that had been left to us. And Petrina and I corresponded on some garden chat sites. And she said, let me cross some tomatoes. Let's pull a project together. and we just decided let's make it open source.

Let's tell people exactly what we're doing, which varieties we're crossing. Let's in list people who, once it's made clear, they're not going to get paid very well, as in zero. The reason they're going to want to do this is they will learn a lot about tomato genetics. They will help create things that people are going to love to grow in their garden, particularly as container gardening became more important. So we just ticked along, made the first crosses, 2005. I distributed seeds out. We released our first ones in 2010. When you said you cross-bred the tomatoes, you're not talking GMO. You're talking about pollinating each one by hand? We're talking

Gregor Mendel. We're talking, you know, going up to one of the indeterminate and tall-growing, delicious ones, such as a Cherokee purple and collecting pollen from it using an electric toothbrush. and then going up to one of the few existing dwarfs at the time. As an interesting aside, the very first dwarf tomato appeared in an American sea cattle like in 1850, but the tomato wasn't very good on it. And nobody really took advantage of the fact they could breed different tomatoes to it to upsize them and increase the flavor. So we would go up to a dwarf and go to a flower and pull off the little anthers and

expose the pistol, dip it into the pollen. If a tomato developed, we mark it, and that is the hybrid. That is the starting point. Each of our families starts with a hybrid and the seeds of which we distribute. And that is the Forest Gump box of chocolates because you never know what you're going to get when you start growing out seeds from the hybrid. Is that why the volunteers grow them for you to see what comes out? Yeah. And so one of the attractions to this is if you find a great-tasting unique dwarf,

you get to name it. So we have cats and turtles and dogs, aunts, uncles, and flowers. And in America, there really is no stringent requirement to register names if you're an amateur breeder. And then it goes through six to eight minimum generations of selections because you have to get rid of all of the things you don't want. And you don't get total stability. If you find something great at the third or fourth generation, If you grow those seeds out, you'll still see some noise. And you select for what you want. You keep doing that. And by the time you get to the sixth or eight generation,

the nice thing is you've got a new, stable, open pollinated variety that you could save seeds from, offer them to seed libraries. And then in the catalog, your name will go in the description of the tomato that you help develop. So it really is citizen science. It really was, we felt, a unique way of doing this. this. And when I finish my book at the end of the year, I want to call it crowd breeding, because to me, it's a new word, which is required, I think, for a new way of doing this type of collaborative breeding project. So these seeds can't be patented. As you say, they're open source? Yes. Not only are

they open source. We have pledged them to an organization called OSSI, the open source seed initiative. and once seeds are pledged to them, they are available for people to improve, to do breeding with, but they're not available to people to patent. I think of these as some of tomorrow's heirlooms, meaning in 30 or 40 or 50 years, if our great-naring kids are growing dwarf sweet sue or dwarf emerald giant, they'll probably be considered heirloom varieties. And as someone who loves genealogy and history and sharing and sending seeds, that kind of warms my heart, to think that these will just move on through gardens, you know, into the future.

Do you have a favorite dwarf tomato variety? Well, I have to say, my wife will listen to this. So I did name one of the best of all for my wife, Dwarf Sweet Sue. And it's a six to eight ounce, beautiful yellow slicing tomato that has a little bit of a red blush on it. And the flavor, as is expected from the name, is on the sweet side. but it's also very intense and it grows well in lots of different areas of the country. So I really love dwarf sweet zoo, and I love my wife as well.

So it all works. If people want to find where they can get these seeds, where do they go? So when we started distributing samples of seeds to the smaller seed companies, many of them love to do this, but they didn't want to have their catalog taking over with the dwarf varieties. But victory seeds is incredible. And they have essentially dedicated themselves to offering every variety that we produce. And what happens then, Ira, is other companies will decide, hey, these are doing pretty well. The reviews are great.

They get the seeds from victory. And then they offer them in their catalog. Example, Dwar Sweet Sue now, if you Google that, you can probably find it in 20 or 30 different seed companies around the world. So this whole sharing bottom-up approach of just letting word of mouth and the quality spread it around has worked very, very well. I need some pro tips from you before we go. And one of them would be when is the best time to harvest your tomatoes? Let them ripen on the vine for the best flavor. Well, you know, most people love this concept of the vine ripen tomato.

Right. And the problem with that is the tomato is, let's say it's fully ripe and it rains. It will crack. Let's say that it's fully ripe and it's just smelling the whole garden up with aroma. And the passing deer or the passing rabbit or chipmunk or squirrel will say, yeah, sure, I'll take a bite out of that. So what we found is that you can let tomatoes get about half ripe, which means halfway up from the blossom end, you'll have color. From halfway up to the stem end, it will be pretty green. pick those, bring them into the house, just leave them on the counter. If you want, you can put an

apple or banana near them because they, as they ripen, give off ethylene gas. Ethylene gas is the hormone that causes tomatoes to fully ripen. Within three or four days, your tomatoes will be fully ripe. They won't be cracked. And we've tested this in blind tastings. They will have a flavor fully equivalent to that if you let it get fully ripe on the vine. And the other thing is they will have more shelf life because I don't think there's much more perishable than a fully vine-ripe tomato. They really need to be eaten in the garden with juice dripping down your chin. Hard to follow that up with this last question. I know you've dedicated so much of your life to growing tomatoes and teaching others about them. What is it about tomatoes that keeps you coming back

for more? You know, I have this memory of getting into a car with my grandparents when I was really young and driving to a farm stand and then picking through the tomatoes, coming back, to the backyard, having a cook out, and just slicing them up and putting them on the burgers. And so I think there is a strong nostalgic link to tomatoes. I think there is such a diversity. There are actually at least 10 to 12,000 named varieties of tomatoes. And they're every shape, size and color. And you get this incredible variation in flavors. All of that together to me makes it the perfect crop to fall in love with. And, you know, think the tomatoes chose me because why else would J.D. Green have decided to send me this unknown

purple tomato back in 1990 that I got to name Cherokee Purple. And, you know, everything has kind of followed from that. So I'm just along for the ride on this. It's the tomatoes that are to pluck me into the car with them. Well, you were ripe for the plucking, it looks like. Oh, my God. We're going to have to stem this discussion. Craig, it's been delightful. Thank you for enlightening. us about this. We're all going to go out and look for these scenes now. Absolutely, my pleasure. Craig Lohle, are Gardner, author, and co-founder of the Dwarf tomato project based in Hendersonville,

North Carolina. And if you want to learn more about the project and see photos of these dwarf tomatoes, go to sciencefriaday.com slash tomatoes. We have to take a quick break, and when we come back, we'll break down the latest update in the Colorado River Water Distribution saga. Stay with us. This is Science Friday from WNYC. This is Science Friday. I'm Iroflato. The Southwest has been dealing with a water crisis for years. This is really nothing new, is it? As the amount of water available goes down, especially in the Colorado River,

states need to figure out how to reduce the amount of water they use, and really, there's no easy answer. About a week and a half ago, we got one step closer to a solution. Arizona, California, and Nevada presented a plan that, that would voluntarily cut their water use. This comes after a lot of pressure from the federal government, which would have imposed its own plan if states couldn't work it out on their own.

So what's it all about? Here to tell us are my guest, Dr. Sharon Megdal, director of the Water Resources Research Center at the University of Arizona in Tucson, Luke Runyon, managing editor and reporter for KUNC based in Grand Junction, Colorado. Welcome back, both of you to Science Friday. It's my pleasure.

Yeah, thanks for having us, Ira. Nice to have you both. Okay, Luke, can you break it down for us? What exactly is in this proposal? So this is a proposal that's coming from the three states that make up the lower basin of the Colorado River, and that's Arizona, California, and Nevada. And what they're putting forward is three million acre feet in conservation. And for those people not totally drenched in the water world, an acre foot is about, what it takes to supply two average households for their annual water use in the Southwest. And in exchange for coming up with this conservation goal, the states are going to be receiving more than a billion dollars in federal funding from the Inflation Reduction Act. And that was, you know, this huge investment in climate change mitigation and adaptation from Congress and the federal government last year. So, you know, this is a, this is a huge

investment in these lower basin states in order to meet this conservation goal. Sharon, as Luke said, this is going to impact the lower basin states, so Arizona, California, and Nevada. What's this going to look like then for those states? Well, we've already had a partial glimpse of what it will look like because we've been reducing water use based on lower Colorado River water deliveries for a few years now. And what this is going to mean, is less water delivery to some of the users, including agricultural users, who use the bulk of the water, but also to some cities, to some tribal nations. The idea is for less water to be taken from the river so it can remain in the system, particularly in Lake Mead, which is the large storage reservoir

behind Hoover Dam, so that the system avoids crashing. That has been the big, threat that we faced is that nature hasn't been producing enough water, and the storage in the lake has gone down and down. Fortunately, we had a very good winter, which took off some of the pressure. But what it's going to look like is less water use. But the key word is people have agreed to this based on the compensation the federal government will offer, but this is not necessarily the permanent solution. This is just really buying us time for the next three years because there's a big, big renegotiation of how to deal with less water on the river that has to get underway and has to be in place by 2026. So this is breathing room. Some people

are calling it a band-day, but this is not the long-term solution to less water in the Colorado River. Look, Sharon was talking about a wetter than normal year for several Western states. Does that have anything to do with why we're seeing this now? That's a huge reason why this agreement came together. You know, a lot of the discussion last summer was about the even more conservation that was needed on the Colorado River in order to stabilize the river system. And this, you know, huge amount of snow pummel the Rocky Mountains over this past winter. And what that does is it alleviates the pressure on the negotiators, the policymakers who are sitting down at the negotiating table coming up with these agreements. You know, the sense of urgency among all of those people decreased as that snow started piling up.

You know, you've just got a tremendous amount of new water that's entering the Colorado River system this year. But, you know, that's a short-term boost for some of these reservoirs. what we know in the southwest is that the region is warming and drying. And so you can still have these really wet years, but the trend is towards warming and drying. And how will this plan look affect the upper basin states at all? Not yet. You know, this agreement is really coming from the three lower basin states. And this was a negotiating tactic on behalf of the four upper basin states, Colorado, Utah, Wyoming, and New Mexico, who basically said, you know, the bulk of the volume of water that's used in the Colorado River Basin is in the lower basin states. They're the ones who

need to be putting forward this conservation right now. And, you know, it's not our turn to be putting forward these, you know, hard conservation agreements just yet. Sharon, I mentioned at the top that if the states hadn't come up with a plan, the federal government would come up with one of its own. And do you think that was a scary thing for the states? Absolutely. That is something the states always want to avoid. And actually, the federal government wants to avoid that as well. Because the concern is that if the federal government imposes its solution on the states,

it is very likely to make one or more of the states or parties within the states unhappy. And then people go to the courtroom and things get delayed. or all mixed up in the courts, which don't produce any more water, just delay implementation of solutions. Yeah. And so everybody wants to avoid that. But what was happening, and this is why the breakthrough that was announced, you know, a week and a half or so ago, was so important, was that you had Arizona and California,

the two biggest users of Colorado River water in the lower basin, not in agreement about sizes of cuts and distribution of the cuts. And the federal government was not on board. But yet, as I've heard, it maybe Luke's heard, through some almost sleepless nights and negotiation over the weekend, they came to agreement. And the Upper Basin signed on as well, because the Upper Basin is always watching what the Lower Basin states are doing to make sure that they're not adversely affected. And they came to agreement, which I think was just a big sigh of relief. And the federal government indicated that it is pulling back this process. It's suspending the process that was underway looking at the two alternatives they had put out in addition to the do nothing alternative.

And everybody agreed the do nothing alternative is not an alternative. And now they're going to reissue their environmental impact statement for review with this new agreement as part of And so I don't know how long that'll take, but I think everybody is breathing a sigh of relief, at least for the short run. Right, right. Luke, what comes next? How does this actually work? I mean, did they actually stop pulling water out?

And people say, well, I can't use as much water. Do you need the cooperation of the public on this? Well, some of the states that have signed on to this agreement say that they're ready to start implementing this right away. And some of this gets down into the weeds of, you know, contracting with irrigation districts, large agricultural users in the lower basin. But yeah, some of these cuts are going to start being implemented right away. They're not necessarily waiting for this federal review process to finish. They say, you know, we've got this agreement in place. We're ready to start taking less water from

the Colorado River. But really what comes next is this breathing room that Sharon mentioned. You know, this is really the states gearing up for an even harder set of negotiations that are going to be taking place over the next three years to come up with a new state. set of managing guidelines for the Colorado River. Those were first agreed to in 2007. They expire at the end of 2026. And that's really where the extremely hard conversations are going to be had. Sharon, if this proposal does move forward and it's successful, will it actually be enough to slow down how quickly the Colorado River is drying up? It won't slow down how quickly nature has the Colorado River drying up.

will slow down the implications of that by preventing the system from going so low in terms of storage that you can't produce hydropower, that you are even risking water getting past the dams to be delivered downstream of Hoover Dam. And so nature is nature. And even with this new agreement that we expect can get us through the next three years, that's. not guaranteed. If we follow this very wet winter with multiple very dry winters, this agreement may have to be adjusted and more cutbacks put in place. Wow, that is an interesting case. We will have to follow along with you. Thank you both for taking time to be with us today. Thank you for having me. Yeah, thank you, Ira. Dr. Sharon Megdal, Director of the Water Resources Research Center

that's at the University of Arizona and Tucson. Luke Runyon, managing editor and reporter for KU.S. BNC based in Grand Junction, Colorado. This is Science Friday from WNYC Studios. One of the most iconic symbols of the Southwest is the Swaro cactus. You know the one, the big tall cactus with branching arms that has a G in its name that you don't pronounce. Well, the Swarrow are the most studied variety of cactus, and yet there's still much we don't know about them. Once a decade, researchers from the University of Arizona survey plots of roughly 4,500 Swaro to assess the health of the species.

And this year, there was a record low number of new cacti growing, the fewest since they started Decadal Surveys in 1964. Wow, what's driving this decline? Joining me now to talk more about the state of the Swaro cacti and their role in the Sonoran Desert ecosystem is my guest, Peter Breslin. postdoctoral researcher at the University of Arizona's Desert Laboratory in Tuma Mark Hill, based in Tucson. Welcome to Science Friday. Thanks, Ira. That's great to be here. Tell us about that survey. Were you surprised at what you found? We were surprised,

especially by really the very low number of small or new recruit. We call them new recruits, like they're new to the population. So the small swaros were really, there were only a third, 33 that we were able to find, and that's out of a total population of more than 4,000 saueros. So we thought because of the drought and because of other factors such as changing climate, that there would be very few new swaros. The whole Sonoran Desert runs on a couple different cycles of precipitation, summer, we call them the monsoons, and then winter rain.

So it's a bi-seasonal rain pattern, and that has been disturbed over the weather. the past 20 years or so. And when you put that together with the drought, you get conditions that probably just are not conducive for the sorrows to establish. Is there any invasive species that might be driving them out? Yes, it seems as if the colonization by non-native grass

that's called buffalo grass is excluding a lot of new sororow recruitment in the population. because what we're finding is a very strong negative correlation between the buffalo grass colonization and where the new soaros are. They're not colonizing where the buffalo grass has started to take over the landscape on the hill. Now, the population is not evenly distributed right across the landscape. Do you know why some places are better than others for the cacti to thrive? Well, that is. is the $64,000 question. The current research project that we're doing and the publication that we

hope to get out of it is exactly to answer that question. Why are Suarez establishing where they are? And where are the conditions, where the Suarez are avoiding establishment also. And our hope is that we can take that information and make it useful for people who are doing Sawaro residents. restoration projects and other management, such as the folks at Swarrow National Park. I understand that they have a really interesting growth pattern. Tell me more about how Suaros grow. I really just find it fascinating that their life strategy, so to speak, is to grow very, very slowly for the first 10 to 20 years of their establishment on the landscape. They really are in no hurry whatsoever, sometimes as slow as a centimeter a year of new growth in their protected habitat.

And then once they get to a certain height, sometimes when they're above like a vegetation canopy and they get more sun or other times just sort of apparently randomly, they really take off and they grow a lot more quickly. And then they reach flowering height. Maybe they start to put arms out. And keep in mind, this is after about 70 years a lot of the time, they slow way down. It's not a linear growth pattern. It's got this growth spurt that happens for a few decades there, and then they slow down again. Yeah. How long did they live in general?

It varies, of course, depending on all kinds of things. But the amazing thing about Suaros is that they lived usually about 150 years old or 200 years old. And so we humans, you know, we have a 60-year data set from these repeat surveys on Tuma. We call it a long-term data set. But, you know, 60 years, something that germinated in 1964 might not even be flowering yet. 60 years later. And so it's not even half the lifespan of a typical Swaro. So we try to think in Swarro time, you know, not human time when we're trying to understand these plants.

You know, when some plants go away or they die, there's an effort to, like, replant them. Can you replant more cacti? You can. It's a difficult restoration feat to accomplish. I know that the Tucson Audubon Society is sponsoring a major replanting of swaros in one of the big fire areas near Tucson. And it's an awesome project. We're all very excited about it. I'll be interested to see the survivorship after 10.

20 years if I'm still around. When you say awesome, what kind of scale are you talking about? I think the current plan is to put 4,000 Suarros out into this burn area. And one of the weird things about it, too, is that they're actually having difficulty obtaining that many Suarros from cultivation. So there's an unexpected sort of sororough gap from local nurseries or other sources. So how dire is the situation here in terms of the future of the source? Suaro cacti? Well, I'm not sure if you ask a swarro, they might say, no, I'm fine. You know, they're very resilient. This is a desert adapted species, and they're really tough. So you have decades and centuries of adaptation. On the other hand, we have a lot of rapid change going on in

precipitation, temperature, the buffalo grass situation, and the rapid change comes up against the slow pace of the Sonoran Desert. So we just need to stay vigilant, I believe. Over the next 30 to 50 years, especially, we'll have a much clearer picture of what's coming down the pipe. Wow, that's very interesting news. Thank you for sharing it with us. Sure. Thank you for having me. You're welcome. Peter Breslin, postdoctoral researcher, University of Arizona's Desert Laboratory and Tumamak Hill based in Tucson, Arizona. We have to take a break on one week. come back. We'll continue our conversation about the Sonoran Desert and the importance of studying the ecosystem across the U.S.-Mexico border. Stay with us. This is Science Friday from

WN.N.Y.C. Studios. This is Science Friday. I'm Ira Flato. We're continuing our conversation about the Sonoran Desert ecosystem. We just talked about the health of the Suaro, the desert's most iconic cactus. But you know what? The Sonoran Desert is so much more than just cacti. The 100,000 square mile desert reaches across the U.S.-Mexico border. The northernmost portions in southern California and Arizona make up just one-third, one-third of the desert. The majority of the Sonoran is within the Baja California Peninsula and the Mexican state of Sonora. The region also includes the Gulf of California, which is teeming with life. In fact, Jacques Cousteau once called it the world.

Aquarium. What a great vision that is. Joining me now to talk more about the rich biodiversity of the Sonoran Desert and the importance of scientific collaboration across the border are my guests. Ben Wilder, director and co-founder of Next Generation Sonoran Desert Researchers based in Tucson and Michelle Maria Early Capistran, a conservation fellow at Stanford University and board member of the next generation of Sonoran Desert researchers. She's based in Monterey, California. Welcome both of you to Science Friday. Thank you. I have an honor to be here. Thanks. Great to be here.

Nice to have you. Ben, let me begin with you. I think that most people, the Sonoran Desert, starts at maybe Phoenix and ends in the Grand Canyon, right? Do you find that to be true? Do you have that feeling? So, you know, I'm born and raised here in the Sonoran Desert. And when I was a little one, yeah, that was kind of true for me. I grew up with the Suarez in my backyard, and the desert was this area just around my backyard, but I'll never forget when I first learned that, as you said earlier, the majority of the Sonoran Desert is to the south. It's the entire Baja California Peninsula, almost the entire state of Sonoria.

We have our own ocean. It blew my mind, and I've honestly been spent my life since then exploring that. I never knew that either. It is a mindblower. And Dr. Capistrand, do Mexicans feel the same way? They really don't know how big the desert is? Well, I mean, I would chime in that for most people in the United States, it starts at Tucson and ends at the Grand Canyon, right?

I think for most people in Mexico, it starts, you know, where the carnassala starts, right? So just north of where the greenery ends. And at least from the south, from Mexico City, I think it's generally just seen as kind of a vast, empty spot. Northerness would think of that very differently, of course. Well, Ben, your organization, next generation of Sonoran Desert researchers, is out to disabuse everybody of that notion because you're connecting scientists from the U.S. and Mexico as well as local communities. What motivated you to start the organization? What was missing in the way that the desert has been studied in the past? Well, you know, as you said earlier,

this is such a vast region, and the inherent nature, the biological and cultural diversity of this region does not adhere to political boundaries, which are quite often arbitrary. And I was coming of age as a scientist in this region and with a couple collaborators as well at the beginning of our careers, and we were looking around and really seeing like, where is this larger community? Does a larger community exists that that shares a passion for this region and is studying this. And we didn't know the answer to that. It's so important because this region doesn't adhere to these boundaries. We need, we need to be linked. There needs to be connection to properly understand and both work to conserve this region. And so the next generation Sonoran Desert researchers or NGen was born from this

desire to understand if this community exists. And it started with a single meeting in 2012, which the answer to that question was a resounding yes, this community exists, but were fragmented by, in 2012, the increasing fragmentation and strong east-to-west border of the U.S.-Mexico border was digging in. It's dramatically increased since then. So that is a huge impediment, but also kind of an increasing siloization or creating of boundaries across areas of research or disciplines. So trying to bridge the border and to link ways of seeing the world is really where NGEN was born. And from that one meeting, it started a movement of creating a platform for collaboration. Michelle, did you decide to become part of this research collaborative because you agreed with this mission?

Certainly. Yeah, I was really excited to see a much broader community. I joined NGFETA. when I was a PhD student, and I was based in Mexico City doing my field work in Baja California and feeling a little isolated, actually, because, you know, there weren't a lot of people in my physical location who were working in the same area. So being able to connect with a much broader community with the same passion for the desert and the sea was just extraordinary. Ben, you talked about engine and you used the term interdisciplinary research. Talk a bit more about what that means. I think these terms interdisciplinary, and then I'll use transdisciplinary here too, are honestly a bit

jargony. But when I really had them broken down for me by my colleagues that we were creating engine with, it really honestly is shaped, helped transform the way I approach science in my career and kind of almost how I go about my life. And so what I mean by this is interdisciplinary is trying to use different disciplines or perspectives to understand. understand a question. Let's say go out to try to understand what diversity exists in a region. This is a very important aspect the engine leads in is trying to fill the gaps of knowledge. And so you have a botanist, someone looking at the plants and entomologists, looking at the insects, and maybe even have a geologist. But each person is kind of staying within their own space,

their disciplinary practice, but you're talking across those. One of the things that engine really strives to and where the magic really happens is a transdisciplinary approach. And what that means is putting on the lenses of someone else's view of the world and incorporating that into your own approach. And so, I mean, I'm a botanist by practice, but I'm going out with a geologist and I'm not, I'm putting blinders and I'm not looking at the plants. I'm trying to look at where the faults are or what rocks make this up. And then lo and behold, now I understand, why the plants are growing there. But even beyond that it's merging with the social practice.

And one of the things I love working with Michelle is her background is with social science. And my goodness, when we've worked on projects, you know, Michelle will bring up ideas that I've never even considered because it's not how I've been trained or I don't factor in it. And I realize that, oh, my goodness, like thinking about, especially in conservation efforts, what we need to be factoring in so much more than just the biological, And so it's these talking across disciplines, across worldviews, and really merging those that elevate us to kind of another plane, a higher plane that makes so much more possible that

otherwise is not. In terms of transdisciplinary also, and I totally agree, it's definitely jargony, but I think it can be summed up pretty well as looking at multiple academic or scientific disciplines plus non-academic collaborators. So I think kind of the magic also happens. in integrating people who aren't trained in conventional, you know, present-day science. So that includes indigenous communities, rural communities, different people from different sectors. So N-Gen isn't just academics, it's also nonprofits, it's also government.

All of us participating as individuals, non-representation of our institutions, but people with all sorts of different experience and different aspects of how conservation happens on the ground as well as is in the lab. I want to talk more now, Michelle, a little bit more about the Gulf of California. I hear it's a really cool place to study. When most people think of desert ecosystems, they're not thinking about something that's long the sea. So tell us about what's going on there a bit. Yeah, well, it's incredible.

I mean, the Gulf of California is a national treasure of Mexico. It's one of the only seas, if not the only sea that's entirely within one country's jurisdiction. So that makes it very important to protect. And I just remember the first time I saw the Gulf of California when I was studying grad school, it was just mind-blowing, seeing cactus growing next to the ocean, right? That was something I'd never seen before, you know, used to palm trees and seeing this contrast of this very, like, arid land. I think arid is perhaps has kind of a connotation that's not great, you know, because this

land is incredibly rich and biologically diverse and just has this extraordinary amount of life. But then you turn to the oceans, and it's just absolutely astounding. I mean, there are five different species of sea turtles. There's all sorts of different species of whales, dolphins, porpoises, sea lions. And what's really incredible is it's a place where kind of cold and warm water meet, right? So you get maximum biodiversity in these places where different ecosystems collide with each other, what scientists call ecotones. So the Gulf of California is a really important eco-tone in terms of the ocean.

It's where the tropics meet the temperate waters. So it's a place where you can see, you know, tropical fish and sea lions together. I think it's probably the only sea in the world that has this type of conditions. So it's just an incredibly, incredibly rich and special place. Now, let's talk about the green sea turtle, because I know you study that in particular, and your work incorporates the knowledge of local communities who live along the sea, and they bring some knowledge that you can use. with them, right? Absolutely. Yeah. I hesitate to say I do it. It's collaborative.

Taking a couple steps back, yeah, green turtles are a very culturally important species in the north of Mexico. So both indigenous and non-indigenous communities have used them as food, as medicine. They also have a lot of meaning in art. They're what's called a cultural keystone species. It's a species that has a very, you know, special, pivotal role in how community relates to the natural world. So in my case, I work with community. on the Baja Peninsula side, rural communities. And so these communities for hundreds of years caught turtles for subsistence purposes. They did so sustainably with very limited technology.

And in the 1960s, more or less, there started to be a commercial demand for sea turtles when the cities along the U.S.-Mexico border started to grow. So that kind of matched up with a time when there was a lot more fishing technology, outboard motors, there were highways built that allowed that demand to be, you know, quickly supplied. And you see turtle populations just dropped dramatically. So now green turtles have been protected in Mexico for over 40 years. Their populations are growing enormously. It's really great news. Basically, the work that I do is trying to talk with the people in the communities, especially the elders who are able to witness the sea turtle populations

back in the 1950s and 60s and try to reconstruct what the population levels were back then. basically by interviewing them and learning everything possible because, you know, these guys, they'll forget more about the ocean than I'll ever possibly know. They're people with 50, 60 years of experience on the water that just is invaluable. It's extremely, extremely important knowledge that's not written down any books. And when they're gone, humanity loses that forever. And this is something that's happening not only in the Gulf of California, but around the world. So, you know, I have the enormous honor and responsibility of being able to work with people to learn from them and hopefully help their knowledge be a fundamental part of how conservation science is carried out because unfortunately, you know, historically, conservation has a lot of colonial baggage where conservation measures or policies are implemented, you know, with varying degrees of exclusion, right? So that's something that needs to change.

This is Science Friday from WNYC Studios. If you're just joining us, I'm talking with Ben Wilder and Michelle Maria Early Capistran about the Sonoran Desert ecosystem. Ben, you know, we talked about how vast the Sonoran Desert is. Can it be viewed as one ecosystem? So I think it can be conceived as one ecosystem with an infinite number of parts. And one of the best ways to think about as a singular entity is actually how an early founding scientist of the concept of the Sonoran Desert Forest Sreeves stated that the Sonoran Desert is

an area of singular biological unity surrounding the Gulf of California. And so that just speaks to the importance of this body of water that Michelle so beautifully described as just kind of a keystone element that. so much of the life in the desert connects to. And one of the simplest ways is the majority of the precipitation we get in our summer rainy season, the summer monsoon or the Mexican monsoon, is derived from the Gulf of California. And that makes the majority of the entire Sonoran Desert tick. And so what would you like to know more about it that you don't know?

I'll only have a few minutes left. Let me ask both of you first, Ben. Tell me what you need to know or would like to know more about what you study. Oh, my goodness. I that is probably one of the harder questions you could ask because it because what the beauty is that anywhere you dig into so I continue to work on cacti on those the description michel said of the seeing cacti next to the desert that captured me and that's one of the main areas of focus and 25 years in now I feel like I barely understand anything and one question leads to another And so looking at the connection of the diverse waters and how birds bring that nutrients onto land and feel the cactus growth, and then how that ripples out through the rest of the ecosystem. And Michelle, you?

I mean, I would definitely agree with Ben's take. There's always going to be more and more and more to learn. I think it's inexhaustible. I would say, at least for me personally, it's looking into what is the future potentially going to be like, right? because this is also an area that has all sorts of different human pressures. Climate change is going to have a whole bunch of effects that, you know, we really don't know yet, you know, what they're going to be. And I think we need all hands on deck right now to face those challenges

and hopefully do it in a way that's more equitable and more just. Are the green sea turtles? Are they going to migrate because of climate change? Certainly in the Pacific, we're seeing green turtles moving farther and farther north. So the work I'm developing now is on the Pacific side. partly in the Sonoran Desert. And what we're trying to do is look at what fissures and what coastal communities know about green turtle habitats and basically use them to map where green turtle habitats are today and then project that onto the

future and see where they might be in 30 or 50 years. So we are seeing more and more turtles in Southern California, for example, which seems to be a new phenomenon. And the populations are really taking off. And so, yeah, we're going to see a lot more turtles interact. with urban areas, for example, or just moving into places where they're not expected, right? So a lot of changes are going to happen. Also, Cetral, sex determination depends on temperature, right? So above a certain temperature, they'll be either male or female. So one problem

that's starting to happen is that a lot of populations are no longer producing enough males. That's going to be a big problem in the future. We've got to end it there. We have run out of time. Such fascinating work. I'm jealous of you guys being able to go study all of this stuff. Come and visit, please. Anytime. Absolutely. I want to thank my guest, Ben Wilder, director and co-founder of Next Generation Sonoran Desert Researchers, based in Tucson, Arizona.

Michelle Maria, Early Capistrand, David H. Smith Conservation Fellow at Stanford, and board member of the Next Generation of Sonoran Desert Researchers. She's based in Monterey, California. Thank you both for taking time to be with us today. Thank you. Thank you. And that's about it for this hour. If you missed any part of the program, you would like to hear it again,

subscribe to our podcasts. We're asking a smart speaker to play Science Friday. And you can say hi to us all week on social media, Facebook, Twitter, Instagram, our address using email the old-fashioned way, SciFri at Science Friday.com. Have a great weekend. We'll see you next week.

I'm Ira Flato.