#37: Dr. Stuart Weiss – Of Checkerspots, Cars, and Cows

#37: Dr. Stuart Weiss – Checkerspot Butterflies, Cars, and Cows Nature's Archive


Today, my guest Dr. Stuart Weiss tells us about an amazing and unexpected series of discoveries that connect cows, cars, and conservation, all triggered by the study of the threatened Bay Checkerspot butterfly. These discoveries have had reverberations across ecological circles and have led to amazing conservation successes, despite a senior US Air Force official calling the tiny butterfly a national security threat.

Before we get into that, a bit about Dr. Stuart Weiss. Dr. Weiss has a PhD in Biological Sciences from Stanford University, and is the Founder and Chief Scientist at Creekside Center for Earth Observation. He has 29 peer reviewed publications and has wide-ranging research experience in conservation and population biology, microclimate characterization, and statistical analysis.

Today’s episode begins with a bit of background to set the stage, describing the land where these discoveries occurred, what makes them unique, and then a bit about the Bay Checkerspot. This butterfly had been in decline for decades, first due to direct reduction of habitat due to development and invasive non-native plants. But Dr. Weiss’s systematic study showed that something else was happening, leading him to unravel the mystery, revealing an unexpected relationship between cars, cows, and the checkerspot that we discuss today.

Bay Checkerspot Butterfly, Photo Copyright Michael Hawk

Dr. Weiss’s work also showed that landscape and population connectivity was a critical, and missing, component. This was at a time where connectivity was not well understood – and even today policymakers and the general public is often unaware of how important it is. 

Ultimately, the story of the Bay Checkerspot and the cascade of conservation discoveries and actions is an amazing success story that continues to grow. 

I hope you enjoy the discussion. I promise you’ll learn a bit about not only the checkerspot, but also soil ecology, the nitrogen cycle, the nuance of land management and grazing, tule elk, and much more.

Tule Elk on Coyote Ridge, overlooking Coyote Valley. Copyright Michael Hawk.

Note that there was a bit of scratchy audio at a few spots, but stick with it because we did get it worked out.

Lastly, I expect to release an episode specifically covering wildlife connectivity and wildlife crossings in the next few weeks, as well as another that will deep dive into soil ecology. So if you enjoy those aspects of today’s story, stay tuned for those upcoming episodes!

Did you have a question that I didn’t ask? Let me know at naturesarchivepodcast@gmail.com, and I’ll try to get an answer! I’ll add these Q&As to my monthly newsletter, so if you aren’t already subscribed, go here. I promise, no spam. I share the latest news from the world of Nature’s Archive, as well as pointers to new naturalist finds that have crossed my radar, like podcasts, books, websites, and more.

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Bay Checkerspot butterfly

Bay Area Conservation Lands Network (CLN)

California Native Plant Society

California Rangeland Conservation Coalition

Committee for Green Foothills (now just Green Foothills)

Cows, Cars, and Checkerspot Butterflies – Dr. Weiss’ 1999 Research Publication

Creekside Science

Edith Allen at UC-Riverside

Howard Baker and the Snail Darter Controversy – wikipedia

The Moore Foundation

Tule Elk

Valley Habitat Agency

Music Credits

Opening – Fearless First by Kevin MacLoed

Closing – Beauty Flow by Kevin MacLoed

Both can be obtained from https://incompetech.filmmusic.io/


Transcripts are automatically created and are 95%+ accurate. Apologies for any errors.

Stu Weiss

[00:00:00] Michael: Okay, Stu thank you for joining me today.

[00:00:02] Stu: It’s a pleasure to be here.

[00:00:03] Michael: So today we’re going to focus on a really amazing relationship between the bay Checkerspot butterfly and the majestic coyote Ridge and all the different points of interest that connect those two. And I’m really looking forward to getting into it because this is a topic that I can literally view right outside my back door.

[00:00:23] I can see coyote Ridge from my house. So I’m super excited, but before we get into the main topic, I’d like to hear a little bit more about you and where you grew up and how you got interested in.

[00:00:32] Stu: So I grew up in suburban Philadelphia and the event that really set my course was earth day 1970 when 20 million Americans showed up and said, we’re tired of dirty air and dirty water. We need to do something about it. I was 10 years old at the time and my dad was a anti-Vietnam war activists.

[00:01:00] So I kind had the activist, gene and culture in my family and I pursued biology and high school. And then I had the chance to come out to Stanford in the fall of 1978. And I got a work study job. My first work study job was in the second basement of the engineering building, studying sewage water, because that’s what was available.

[00:01:27] But then I had the opportunity to join Paul Erlick slab as a lab tech in the winter. And then in the spring, I found myself out on Jasper Ridge biological products. Chasing Checkerspot butterflies and fields of wild flowers. That’s like the classic butterflying that, and all my friends were like sitting in a dark lecture hall and econ one with other students.

[00:01:53] And there I was, running around in the California spring, doing what turns out to be very serious scientific research. So I got hooked really fast.

[00:02:03] Michael: And how was it that you got connected to Paul Erlick slash.

[00:02:05] Stu: Yeah. So I was everything converged really nicely for me to get a work study job in his lab. It turns out his mother was my brother’s Latin teacher in junior high school and was also very good friends with my grandmother. Never underestimate the power of a little family connection then. I was like a mere undergrad field helper in the lab. And, Paul is definitely a very kind of distant professor for a lot of people. But then that first summer I was able to get in on going to Rocky mountain biological laboratory and the Colorado Rockies. And there, I, actually got to know him, a lot better than most people would because we’re up in the Rocky mountains, in a small lab, out doing field wear long time driving.

[00:03:03] And you know, he’s, it’s absolutely brilliant and articulate.

[00:03:06] Michael: So was that experience at the Rocky mountain biological laboratory? Was that the key then to get you the field research gig that you had on Jasper?

[00:03:15] Stu: No, it was the other way around. I started on Jasper Ridge in the spring, and then in the summer I went out to Rocky mountain biological lab and not the brag, but on that first day I caught more Checkerspot butterflies than anybody in the crew. So I got off to a really good start.

[00:03:33] Michael: So that got his attention.

[00:03:36] Stu: Yeah. I think it got his attention enough that got the job in Colorado. It did that for three summers.

[00:03:41] Michael: And was his lab specifically researching the.

[00:03:45] Stu: Yeah, that was his kind of first study organism. And he made us science reputation in butterflies and the act of just going out and picking some kind of random butterfly and start looking at its population structure, its population biology, not because it’s asked or it’s particularly, stands out, and then see what you find, it’s act curiosity driven research.

[00:04:15] That seems to be really downplayed these days. But you know, As you’ll see, it’s just turned into this scientific gold mine, where. And by really delving into a single species or single organism and its habitat, a lot of very general phenomena become apparent and they get documented in the scientific literature. It’s just overall again, did it become clear that the bay Checkerspot butterflies my, like my science and conservation news, that’s what I always go to when I need to think about a issue that somebody brings up. It’s like, how does this apply to the bay checker spot butterfly in my experience.

[00:04:57] Michael: Interesting. So it’s the lens through which you find all of these other rabbit holes to go down.

[00:05:02] Stu: Yeah. Yeah. Follow the butterfly, follow the path of the butterflies.

[00:05:06] Michael: So then I suspect that the bay checker spot is, and we’ll talk a little bit about the bay checker spot in his biology here in a bit, but the, that’s what led you to coyote Ridge. Okay. Can you connect those dots?

[00:05:19] Stu: Yeah. Sure. So we had, been working at Jasper Ridge, which is really only about 20 acres or so of serpentine grassland habitat. That’s where the classic long-term studies were. Then. We started doing some work out at Edgewood, par a little bit north, and that seemed huge where we had 40 or 50 acres of serpentine grassland, and a much bigger Checkerspot population. And then the, after I graduated, One of the guys I worked with in the lab had gotten a call saying, oh, we found bay checker spot butterflies down here, while doing surveys for a large proposed landfill. So they called him and I ended up starting to do a lot of fieldwork. So I first set foot on coyote Ridge.

[00:06:12] I think it was in February, 1984. And it was just a revelation because instead of having this massive 50 acres of serpentine grass, There were suddenly like thousands of acres. We had, we didn’t have any idea when we first went out there just how big it was. And, until we brought up the geologic maps and realized the scope of it, and it also had this incredible amount of typography, there’s about 300 meters, about a thousand feet of elevation, and it’s all cut up by these canyons and the canyons create a posing north and south facing slopes.

[00:06:54] Some of the slopes are ridiculously steep and you’ll almost fall off of them. And I took a couple of nuggets from some research on Jasper Ridge about the importance of topography and how south facing slopes get a lot more solar radiation, then north facing slope. , and that affects the phenology, the timing of when butterflies fly and when plants flower and CNS, and it had been described at Jasper ritual.

[00:07:26] We finally suddenly had this area where you could just really get at it because it was so densely occupied by bay Checkerspot butterfly larvae and adults. It was really dense. So we had the opportunity and, the second year I was out there, I started pulling up samples of Caterpillar’s from different slopes and weighing them and the Caterpillar’s on the south facing slope or 250 milligrams.

[00:07:58] And the ones, about a hundred meters away, we’re only 50 milligrams or 25 milligrams. They’re just tiny in comparison. And then we just started monitoring, how fast that the Caterpillar’s grow when they come out as adult butterflies and how their host plants, the Plantago erector, the core plantation flowers and dries out and how the relative timing of those is what’s driving the population to go up or down.

[00:08:30] And it’s mediated by topography because you get like a four or five week difference between those opposing slopes of when the butterflies come out and when the plants dry out. So it’s all mixed up on a really fine scale. So kind of. description, just all these studies we did that it was 1985, or we really did that.

[00:08:51] And I got a paper published in like the top journal ecology. , it was a part of a series of papers that came out in the 1980s, really defined this. One of the cooler experiments we did we’d collect Caterpillar’s. We put little dots of paint on them in a code, so we could recognize individuals we’d let them loose. And then we come back a few days later and see how far they moved and how fast they grew. And we found out that a, we could predict the mass gain. By looking at what the solar radiation on that slope was during that period. it was a lot faster on a south facing slope than on a north facing slope. Then we also found out that these little guys could crawl like 20 meters a day when they set their little ganglia to it. And and actually move from move off the steep north facing slope into an area where they can grow a lot faster. so they can get a jump on the plant and have higher success of their offspring, because most of the mortality takes place. In the spring, when the plants are drying out, you have these tiny little Caterpillar’s that just hatched. That are like desperately feeding on the plants as they’re drying out. And the vast majority of them die because of starvation. We were actually able to really document that, well enough to get a published and really the top ecological conservation journals.

[00:10:28] Michael: That’s it. There’s a lot of branching points here, I think. And I want to maybe back up a little bit you said this was 1984, right?

[00:10:35] Stu: Any 84 is my first encounter out there. 85 is when we started doing more of the research.

[00:10:42] Michael: Okay. And at that point was it understood that the bay checker spot was in decline or threatened?

[00:10:48] Stu: Oh yeah. That, yeah. That’s a part of the story it’s really important to get. Thank you for bringing that up. That was another formative moment in my life is that I was out at a serpentine opera near Kenyatta college. We called it Woodside and collecting butterflies to , try to do an experiment on, why did they choose the plants that they choose to lay their eggs on? And I happened to be out there the day that they were bulldozing the habitat for a housing development. So I literally got bulldozed off of the habitat and I think this was 1980. Paul actually quoted me in his book extinction that was published in 1981. Yeah, and there I was, I made it into a book signing and at that point, he and Dennis Murphy, who was his grad student and a postdoc at the time, petition to get the bay checker spot listed as a threatened species, because , we really thought at the time that, these small populations on the peninsula where like the heart of the distribution, but then it turned out we had this kind of, behind private fences, massive population down on coyote Ridge that we had gotten access to find all that because of the landfill proposal and. That really broke open the science I was describing, but also the conservation opportunities.

[00:12:20] Michael: And you mentioned that the bay Checkerspots larval food plant is the Plantago erector. Can you tell me a bit about that plant and where it’s found.

[00:12:29] Stu: It’s the most important plant in the world, of course. And it’s actually a native California grassland species of Mike’s really thin or disturbed soils. And it used to be like everywhere in the grasslands. So California grasslands have been massively transformed. By the non-native or the introduced annual grasses, and then all the weedy Forbes that came along with those. So that species like Plantago erect uh, became restricted in terms of on Moss, on a really nutrient poor soils like serpents. So that’s where we find the extensive stands. Plantago erect now is really only on serpentine soils because they’re resistant to the invasion of the introduced annual grasses.

[00:13:24] Michael: had no idea. I had thought that the Plantago erect uh, was adapted to growing on serpentine soils, but you’re saying that actually it used to be found more broadly. And it’s the fact that the serpentine soils are nutrient poor that allowed it to hold out.

[00:13:39] Stu: Yeah. And there are eco types of Plantago erector that are more adapted to the serpentine soils than the more fertile soils. It’s really fascinating adaptations to serpentine. Soil’s been a really big aspect of kind of plant ecology plant evolutionary biology. It’s been a big subject matter for that field.

[00:14:02] And yeah, there are a series of species that are really ademic to serpentine. Never find them off serpentine. So as far as conservation value goes, in terms of unique species, serpentine is like one of the real hotspots.

[00:14:19] Michael: So then by extension, if I were. Magically transport myself back 300 years. Would I find the bay checker spot off of serpentine areas I can in other

[00:14:29] Stu: Yes. I will say almost definitely. You would, that there are a few places like on San Bruno mountain that aren’t CertainTeed, where there are still a few stands of like multi acre stands up. Plantago erect. Uh, But it’s the like thin soils up on the Ridge top. But again, they’re just not fertile enough to support the really dense.

[00:14:57] Swards of the annual grasses, but yeah I think you would have found that the bay Checkerspot, might’ve been one of the most common butterflies in the bay area. Pretty much all of the grasslands.

[00:15:08] Michael: I know up on coyote Ridge, they can really be at least some years profuse, like everywhere you look. So that wouldn’t surprise me with what you’re saying. And then back in that night, 19 84, 85. Timeframe did ecologists biologists. Did you have a general sense that, I’m assuming you already knew that there was this relationship between Plantago erector and the bay checker spot.

[00:15:31] So were you seeking out serpentine soils at that point or was this sort of the moment of reckoning where you realized how important it was for the butter?

[00:15:40] Stu: no. W we had known that before and then over the course of the next five years or so we investigated a lot of. Serpentine outcrops especially on the west side of Santa Clara valley in the Santa Cruz mountains. And yeah, we’re able to see where the butterfly had naturally, occupied it.

[00:16:01] And, there were some recorded extinctions and one of Paul’s grad students was able to infer that they gotten recolonized from this massive population on coyote Ridge.

[00:16:15] Michael: So then this. Trigger was the the proposal to build a landfill. And was there a regulation or regulatory requirement to go in and survey the land first? Is that

[00:16:28] Stu: Yeah, because the bay Checkerspot was a candidate species. And remember this was like the Reagan administration and they’d stopped listing species, but it had legal status as a candidate, but you have to treat it as something to be concerned about. you know, We did our surveys and we found that, the landfill was gonna take out a few hundred acres of really nice serpentine habitat out of thousands up there.

[00:16:58] But because of the topography, they were mainly on the south and west side of the Ridge and the butterflies were so much more abundant on the north and east side of the Ridge. So we worked out a deal where waste management, would set aside about 267 acres on the Northeast side of the Ridge.

[00:17:23] And then they would be able to develop their landfill on the Southwest side of the Ridge and they would fund the monitoring and the research. And, but most importantly, they went to Washington, DC and literally lobbied to have the butterfly listed. There’s this great story that ended up in the wall street journal and some other media where the company that owned the land to the north. What was United technologies corporation, big defense contractor. They’re the ones who used to be you doing ground tests or rockets back behind the Ridge there. And, they just had, this knee jerk reaction. It’s like, oh, endangered species, we’ve got to fight it. So we had to set up between the good garbage company and the evil defense contractor.

[00:18:14] And it was just like journalistic cuisine to be able to, just set up this opposing stories with, the poor innocent butterfly caught in the middle of it. And one of the great ironies of this lobbying was that the lobbyists that waste management had hired in Washington, DC was Howard baker who was of snail darter fame.

[00:18:40] He’s the guy who said, when he was a Senator, we got to have this dam, and, we’ll overrule the endangered species act as it applies to the Snell gardens, really big deal back in the eighties, but he ended up lobbying for the listing of the bay.

[00:18:55] Checkerspot butterfly supported by waste management on. And another thing that came out of this, there was a letter from the under secretary of the air force to secretary of interior. Talking about how the bay Checkerspot butterfly could be a national security threat, because it would stand in the way of development of these important nuclear delivery systems. And, I’m like the 20 something year old, hippy dippy biologist, just, watching all of this and coming out of a, peacenik background, it was just pretty amazing to have a front row seat to this kind of, wheeling and dealing and , the act of conservation policy. It really made a big impression on me on, how do you navigate that?

[00:19:46] Michael: I’m thinking too, about how the comment of the checker spot being positioned as a national security threat, the hyperbole and the kind of propaganda and, all of that tied into that sort of statement. It would really be eyeopening, I think, for someone in their early twenties.

[00:20:03] Stu: Oh, yeah.

[00:20:04] Michael: but do you have a sense for why waste management was keen to to advocate for that?

[00:20:10] Stu: Yeah. They wanted their landfill. They would get their deal in which, was acceptable to them. It was a minor capital costs to them. , they get in on the ground floor and get their deal grandfathered. There was all the people coming behind them. know, The next group of people who’d have to deal with the consequences of having a listed species.

[00:20:33] Michael: so this the Ridge, we you painted a bit of a picture of coyote Ridge being a serpentine grassland with these steep canyons. And by the way to me, when I first saw it as a lay person, it looked pretty homogenous. It just looked like a grassland and yeah, there are those ridges, but I wouldn’t have even thought that would be important.

[00:20:53] So that’s an interest. Tidbit that I’ve learned over the years. But can you tell me a little bit more about the Ridge where it’s located? Y yeah, this was obviously important that it had the bay checker spot, but I know it’s important for a lot of other reasons as well.

[00:21:05] Stu: Yeah. So the Ridge lies and Southeast San Jose, it’s one of the largest serpentine outcrops in the bay area. And it’s on the frontier of the suburban sprawl, especially the north end of it.

[00:21:21] And it’s just like this Wonderland. It doesn’t look like anything when you’re driving by on highway 1 0 1, it’s just kind as barren looking Ridge. Although if you look closely don’t take your eyes off the road too much. But if you look closely in the good spring, you’ll see there’s patches of yellow and purple up there. But until you like get out and get on the ground, you don’t realize that, it’s like more wildflowers. Than you ever could have imagined in one place. And it just goes on and on, for miles up and down canyons. And it’s just like the diversity and the colors are just absolutely mind blowing and the way it changes, through the course of a season and from year to year and from slope, the slope, I just always, every year, I’m just absolutely, transported at some point by the beauty of the flowers out there.

[00:22:21] there’s different flowers coming into bloom on different slopes. You get these amazing combinations of colors. And it’s what I call the coefficient of beauty being very scientific about. Which you know, is that kind of buzz you get in your visual system when you’re just in a place that is just overwhelmingly colorful and beautiful. And we actually came up with some scientific terminology for it. Of course they call it, I sub B because beauty is in the eye of the beholder.

[00:22:55] Michael: That works.

[00:22:56] Stu: That’s something that made it out of the field and you can get the feeling. If you read some at John Muir, you know, when he gets into these kinds of places, he’s just starts describing it. And I know exactly what he’s going through. We actually have a couple of John Muir quotes that Craig Edgerton had dug out about walking along coyote Ridge back in the 1868. You know, as a, As a place to conserve, it’s just such a no brainer. I mean, You get people out there and it’s of course we have to protect this. Does it’s the most beautiful wild flowers I’ve ever seen? And it’s like right here in our backyard and there’s thousands of acres of.

[00:23:36] Michael: I know. And it’s unfortunate as you described, when you drive by on the U S 1 0 1, which is a highly traffic road, you can’t really see this. It just looks like grassy Hills and and it is, it’s so amazing when you get up there. It’s like, really? This is what it looks like up close. I had no idea.

[00:23:54] Stu: Yeah. I had a hint of it. I think it was in 1983. I was on the way back from Botney field trip to the Pacific Grove museum. They were having their wild flower show and we’re just driving back up and I’m looking over there and it goes that really purple and yellow I’ve seen over there.

[00:24:15] It’s like, no, I must be, tired. And then, the following year when I got up there, it’s yeah, it really is.

[00:24:22] Michael: You have to be looking for it and at the right time. So you described that this is sort of on the edge of urban sprawl and San Jose, which is a pretty sprawly city. And San Jose is also part of what a lot of people know as Silicon valley. As well. So you have this sort of dichotomy of nature next to technology, but I know that coyote Ridge is also interesting because of its proximity to coyote valley and the Santa Cruz mountains. Can you tell me a little bit about what you’ve learned and discovered over the years in in that respect?

[00:24:56] Stu: Yeah. Yeah. So it county Ridge is at the edge of this massive open space in the Mount Hamilton rate. So you go east. There’s hundreds of thousands of acres of open ranch land. A lot of it is now conserved and it comes right up to highway 1 0 1 and then we have coyote valley down below it. And then over on the west side, the foothills of the Santa Cruz mountains.

[00:25:24] So it’s one of the few places where there’s a chance for wildlife to get from Mount Hamilton range into the Santa Cruz mountains. It’s not an easy journey. You have to go through culverts and risk being on roads and stuff, but it’s really one of the last wildlife linkages.

[00:25:43] And, over the years, there’s just been all these development proposals in coyote valley. So back in the eighties, I think it was apple and tandem. Computer wanted to put in a huge development down there in the late nineties. Cisco wanted to put their world headquarters right down there as part of Cody valley research park. And then in the mid two thousands people were pushing to have a city, the size of mountain view developed on the valley floor. And one of the things I noticed is that every time a coyote valley development started getting some momentum for the development, the economy would crash or there’d be a tech crash, and the plans would go away for a few years.

[00:26:30] I just thought that was an interesting leading economic indicator kind of wish I had based my stock investments on that. But.

[00:26:37] Michael: Yeah, like the connectivity aspect is really interesting. Circling back to coyote Ridge, when these discoveries were being made, who owned land on the Ridge back at that point?

[00:26:48] Stu: . like most places, that’s the mosaic of ownership, waste management, leased land from castle and Cooke, castle and cook is like the landholding are of like Dole pineapple.

[00:27:01] It’s out of the area owner a little further. North was United technologies. A little further north, you had goes by various names, announced, known as the young ranch, then the Richmond ranch.

[00:27:14] And then at the very Northern end, we have the silver Creek Hills. So yeah, they’re generally large parcels. But yeah, it’s an array of different ownerships with, different interests and, objectives.

[00:27:28] Michael: So then at this point, when the deal was struck with waste management, that was the first land that was set aside for conservation up there. Is that correct? Yep. So now you have a little bit of a foothold for the paycheck.

[00:27:41] Stu: exactly. Yeah. I forget the exact timing on it, but yeah, it was not protected at all. And, frankly for, almost 15 years after we worked out the landfill deal, just, there was very little formal conservation now.

[00:28:00] Michael: To this day, cattle grazing is an important part of coyote Ridge. I’m wondering if cattle grazing was occurring back at that point.

[00:28:06] Stu: So back when we were really getting going, the land was braced, we got to know the ranchers a bit and we realized that they were absolutely central to conserving this place. Some Stanford scientists had fenced off an area to do a big nutrient addition experiment in the thing, 1985. And the area that they had fenced off, like in two years was this incredibly dense ward of Italian ryegrass that wasn’t supposed to. Be there on the serpentine soils and nobody had figured out why it’s happening, but the simple empirical fact came to us. Like we got to keep the cows on here. So that became like the major conservation management recommendation.

[00:29:00] Michael: and if I could interrupt real quick, you say that the Italian ryegrass like shouldn’t have been on the serpentine soil. Back because the serpentine soil shouldn’t the nutrient requirements of Italian ryegrass were greater than what serpentine should be able to provide. .

[00:29:13] Stu: Yeah. Yeah. Yeah. Italian ryegrass likes a rich environment, especially when it grows that dense. And then it forms a really dense fat that Smothers out all the little wild flowers. So like out competes the wild flowers and then Smothers.

[00:29:31] Michael: So then you observed that where the cattle were grazing , the rye grass was not growing as thick. The Thatcher wasn’t forming. It was thus allowing the Plantago erectus to sustain.

[00:29:43] Stu: yeah, just all the wild flowers. The contrast is really quite striking and the reason for that is cows eat grass. That’s what they do. And the Italian rye grass is like the best forage grass out there. you know, I learned that the ranchers goal was to remove as much of the grass in a given year as possible without trashing the place, which was exactly our goals.

[00:30:10] So we, it was just really easy to Interact with them and, just have a mutually acceptable arrangement. The question then was like, why is this happening and why aren’t we seeing it up at Jasper Ridge or at Edgewood or these other serpentine areas? That’s when I had gone back to graduate school.

[00:30:35] So I spent 10 years working on the research staff at Stanford. Then I went back to graduate school at Stanford to get my PhD. And I was sitting in a ecosystem ecology class, and the professor Peter gave a lecture about something called dry nitrogen deposition. And it was like the light bulb went off in my head and I think it was the magnitude of the Las Vegas strip by the time it was over.

[00:31:03] And I made all the connections because I’ve been staring up at the small cloud for about a decade at that point. And then it just suddenly, few back of the envelope calculations and it’s yeah, that’s a lot of nitrogen coming down. And that was the moment when I knew that this was an amazing connection here. Took me about five years to bring together all the threads of evidence and teach myself enough about nitrogen. Nitrogen is a really hard subject. It’s a really slippery biogeochemical cycle. It takes a while to get facile with it. And then I published a paper in 1999 that described the phenomenon.

[00:31:43] It’s called cars, cows, and Checkerspot butterflies. And it’s become a bit of a citation classic at this point because I had made a really direct connection between the nitrogen deposition and the loss of biodiversity.

[00:31:56] Michael: So the nitrogen you mentioned it’s coming from smog and from reading your paper, most of that smog is automobile emissions. Is that.

[00:32:04] Stu: Yeah, the majority of it is it’s every. Every source is contributing, but yeah, in the Silicon valley, it’s primarily a vehicular traffic.

[00:32:14] Michael: So then, this light bulb moment in the lecture, did you stay after class and talk to the professor and be like, Hey, I’ve got this idea. I’ve seen this.

[00:32:24] Stu: I, cause he had been one of the professors who was working on that nutrient addition experiments. I had went off to him afterwards and got Peter, you know, why I now know why the grasses came in so strong in that experiment you guys did about a decade ago.

[00:32:41] And then he sent me off to go talk to a civil engineering professor who specialized in air pollution. And then I just started, following all the threads. And develop the enough of a knowledge base to write a scientific paper and get it published in conservation biology.

[00:33:00] Michael: So I’m interested in maybe some of the mechanics of the study and also. , if you things, so were you able to actually measure nitrogen content in the soil to validate that the deposition was occurring at the rate that you had prognostic.

[00:33:16] Stu: Yeah. That’s a really interesting that the paper was much more bringing together the threads of other people’s research. They’d had done all the nutrient addition experiments showing that nitrogen is the limiting factor for the grass growth. Phosphorus helps a little bit, but it’s primarily nitrogen.

[00:33:35] The fact that nitrogen deposition happens was well established and it’s just. Know, really bringing together and synthesizing a lot of other people’s research rather than going out and doing it myself now a little later, I was able to do some of those kinds of studies. We can talk about that.

[00:33:57] After the big conservation moment that grew out of this. So I published the paper in 1999, right? When there was a proposal for the Metcalf energy center, 600 megawatt gas fire power plant, and a smacked at the north end of coyote valley right next to Talari hill, which is a serpent team outcrop.

[00:34:19] And it’s a large source of nitrogen oxides. And this I’ve found that ammonia, it’s a point source and because my paper had come out. The U S fish and wildlife service and the California energy commission told Calpine the proposers of the power plant that they had to do something, we have to mitigate for this.

[00:34:41] Somehow I remember I went to public meeting and I got up and I just said that their analysis that they had was really superficial and not adequate. So then they like took me outside and they were like if we’re doing such a bad job, why don’t we hire you to do it? And, I was a little skeptical at first, but, I figured, Hey, this is an opportunity.

[00:35:11] So I got involved with Calpine and, it’s the project scientists working with them, the energy commission and the fish and wildlife service to work out some mitigation. Then we ended up working out some mitigation that was mutually acceptable all around. There were two intersecting interests here.

[00:35:31] One is Calpine really wanted to build this power plant because it was like the first new combined cycle gas fired power plant in California. There hadn’t been one built for decades and it’s the new, modern, highly efficient power plant. And it was coming in right when we were having the, the electricity crisis and all of that stuff.

[00:35:56] That’s coming to a head at that point. you know, They were willing to, put out extra money as capital costs for a half billion dollar project. So we had this intersection of interest, they really wanted the power plant and, we’re willing to put out a lot of extra what seemed to me have a lot of extra money, but it’s a half billion dollar project.

[00:36:16] 10, $20 million extra for mitigating was part of the capital costs and they were willing to do it. And we really wanted a precedent for mitigating for nitrogen emissions, because we figured we could start leveraging that. So that went through. In 2003, we have this ceremony dedicated in the Metcalf’s energy center, ecological reserve.

[00:36:40] This is quite a scene that they had already flattened the pad for building the power plant. So it’s like this flat barren place, little dust devils going by. And they put up this tent where they have the ceremony and they put out a red carpet and people were showing up. We had a Congresswoman Zoe offering was there and just all these big waves.

[00:37:01] And, I got to give like a 10 minute spiel about know, why are we here? And what’s this nitrogen issue. What’s the butterfly. And it was, that was really really cool. So we had the precedent at the same time was when highway 1 0 1 was being widened from two lanes in each direction before lanes in each direction. And they were like, just about ready to open it up. And the fish and wildlife service said, Hey, wait a minute here, you have to do something because you’re going to be, increasing the nitrogen sources right at the base of the Ridge here from all the cars going by. And also it’s a big growth inducing impact.

[00:37:42] They worked out a deal. Eventually I think it was like about 600 acres of land was set aside. , but it was also the, they made a commitment to enter into developing a regional habitat conservation plan. So this was back in 2001. That there’s a biological opinion, which is an official us fish and wildlife service document that said, you will do this amount of mitigation right upfront, but you’re gonna have to develop a regional habitat conservation plan.

[00:38:16] Michael: Just to fill in maybe a couple of things there. So when the Metcalf energy center, when they agreed to. Mitigate that is separate from the 600 acres that valley transportation authority is mitigating.

[00:38:29] Stu: the mitigation for the Metcalf energy center turned out to be 131 acres of habitat conserved, which means it was box deeded over to a conservation organization. It was a conservation easement on it. They already owned 116 that came with the power plant site. But they had to get 15 more acres over on coyote Ridge because they’re having an impact on coyote Ridge and they needed to do something over there.

[00:38:58] So this was yet another little foothold over there. That’s where this crazy distorted land value market kicked in because the only willing seller was castle and cook. So Calpine ended up having to pay like $27,500 an acre for this little parcel of 15 acres because castle and Cooke was the only player who was willing to sell land.

[00:39:27] Michael: Supply and demand at work.

[00:39:29] Stu: Yeah. Yeah, exactly. So after the Metcalf energy center came in to more power plant projects one in the city of Santa Clara, the Donald Von race fell power plant. And then the lowest is Steris critical energy facility up in Alviso were being developed and they followed the Metcalf energy center model. We got another 80 acres on Cody Ridge for that, but then it was the highway 1 0 1 mini vacation that really blew open the gates because now we’re talking hundreds of acres, plus the potential for a regional habitat conservation plan.

[00:40:09] Michael: and that’s all, all because of the discovery of the impact of nitrogen deposition on this.

[00:40:16] Stu: Yeah, that, that was the major nexus. Yeah, it was a, yeah. That paper generated about $700 million worth of mitigation. When you had a fall, all the project.

[00:40:26] Michael: That’s amazing.

[00:40:28] Stu: The development of the habitat plan was, a bit convoluted, they got the biological opinion around 2003, 2004. they realized , the governments who would agree to this, realize that, oh, we signed onto this thing.

[00:40:43] We’d better get going on it. In 2005, they had signed a memorandum of understanding that laid out. We’re going to do this habitat conservation plan. In the meantime, I got together with my environmentalist friends that the California native plant society committee for green foothills, a little coalition of groups, and we started taking people up to coyote Ridge to see it, like in 2003, I invited all of the elected officials in Santa Clara county to come take a tour and we had it set up. So they would show up we’d shuttle them to the top in our four wheel drive vehicles, nice, gnarly dirt road. And we’d have them for a few hours.

[00:41:29] We’d feed them like this gourmet lunch, then we’d send them on their way back down the hill. And it was transformative. We ended up with some real champions in the elected bodies who realized that, Hey, we’re Santa Clara county. We do things right. And we made this obligation like one person who was a surprise. At the time he was a county supervisor, Don gage. He was like the one Republican on the board of supervisors. But because of his role in negotiating the highway 1 0 1 deal, he felt a deep commitment to seeing this thing through. We have the tours, I nicknamed it operation flower power. So in 2005 days sign the MOU and then it became, just as kind of all the seed mill with the consultants and the part owners and the staff working out the details of the plan. And in I think 2011, they came up with a draft plan. 2000 pages, landed with a huge thud garnered, some opposition because of its size and, ramped it back a little bit. And during that same time we had done another round of operation, flower power, getting people up to see what was wrong, because there had been like one or two generations of elected officials who had gone through.

[00:42:55] So we had to reeducate people, about why are you doing this? That was, again the environmental groups or committee for green foothills Greenbelt Alliance. We got a small grant from the Moore foundation. I was at a event at the Moore foundation with the project manager for the habitat plan.

[00:43:16] And we’re there with the head of the bay area program. And we started talking and he said basically we asked the Moore foundation guy, go and get a small grant to fund this grassroots organizing because the project manager realized we had to have pressure from the bottom. At the same time, the fish and wildlife service was playing the heavy with the regulatory side. And the plan got voted in with all of the elected bodies and a couple of cases, it was close. But then in 2013 we had a celebration of the implementation agreement and that was the birth of the valley habitat agency. And it turned out they got to work really fast. First, really big conservation purchase was Katie Ridge open space preserve, which was the old UTC land that was like 1,860 acres.

[00:44:15] Most of it’s serpentine grassland that was just north of the litigation lands at the valley transportation authority had set aside.

[00:44:24] Michael: And that UTC land. That was like, buffer for where they were doing their tests.

[00:44:29] Stu: Yeah. I They shut down the facility in the nineties. It was just too close to San Jose. Yeah, it was of a surplus land, they got the purchase, the acquisition and yeah. Now next year, I think it’s going to be open to the public.

[00:44:43] Michael: You know, One thing that piqued my interest in this story is the discovery that grazing is helpful. And I know that. Would be conservationists when they hear about grazing, sort of have a immediate adverse reaction to the concept. So I really liked that about the story we use. It demonstrates the nuance, the fact that what works in one circumstance may not work in another or vice versa. So I’m curious about how the grazing is managed. So as not to cause a detrimental effect on coyote Ridge.

[00:45:18] Stu: Yeah. Okay. So the grazing management we work with two ranchers up there. They have to graze really large areas because it’s not highly productive land. And we found out that it’s very self-limiting that they’re removing the grasp biomass and when their cows stop gaining weight, they move them somewhere else.

[00:45:44] If they can, does it doesn’t make any sense for them to have their cows out on these range, lands that aren’t providing them with enough grass to grow or maintain weight. So that part was actually really simple. And we’ve learned over the years to just really trust the ranchers so that it’s not like this real prescription.

[00:46:09] And that’s the worst thing you could do would be say. Put your cows on Ms. State and pull them off on this state, because I think we have such wild weather fluctuations in California that every year is different and just requires a different timing. So that was like a really happy finding them.

[00:46:29] And we discovered that pretty early on the land that was set aside for the Kirby canyon landfill. There was one year where, we are out there it’s looking like it’s getting a little hammered here. And so somebody called the rancher and he had already taken his cows off for the reasons I just described. And we’ve also found that having a diversity of grazing regimes works out there. Winter spring their summer fall or spring summer, they all have different effects in different years and it’s really unpredictable. What’s going to be the best one in any given year. So just give the ranchers some flexibility.

[00:47:11] I mean, They’re in a really tough place trying to make a living off this really flashy environment.

[00:47:17] Michael: That’s interesting. I had just assumed there would have been some., More prescriptive approach to, prevent too much compaction or manure accumulation or, you know, whatever the problem might be. So , that’s interesting to hear. And I’m wondering too, there’s a couple herds of elk that, uh, are on the Ridge.

[00:47:36] Are they substantial enough to make a difference or help I mean, Do they even eat Italian? Ryegrass.

[00:47:42] Stu: we are blessed on coyote Ridge that have elk. They back in the seventies, California department efficient game had released like 20 Puleo elk on the Hewlett Packard grant. Which is the next Ridge to the east from coyote Ridge. And they started , moving over to coyote Ridge, and we started seeing them on a regular basis.

[00:48:06] They eat grass. They can’t be controlled like the cattle have. If you’ve ever seen a fence necessary to, contain Tulio you’d understand why they can’t be controlled. There’s a really, there’s a fence that Sam Lewis national wildlife refuge, that’s keeping the elk in there.

[00:48:25] It’s 15 feet tall, really strong. But w what we found out is that the elk and the cows very peacefully coexist. That the elk to follow the cows around because after the cows graze, there’s all this fresh growth and that’s what they’re really after very nitrogen rich. No, it’s really good forage.

[00:48:47] It’s like a mini Serengeti system that way. And I have a photo that shows three elk cows and three out cabs like right next to two cows and a calf of cattle. It’s they’re just not, they’re not abundant enough or controllable enough to use, to maintain the habitat, but I’m sure glad they’re there.

[00:49:14] Michael: Yeah, it’s one of the allures of the Ridge.

[00:49:17] Stu: Yeah, it’s just breathtaking. When you see this hurt a Tulio, and then you’re looking down on Silicon valley of the background, and I think the Twilio Ackerman amazing conservation story, they had been reduced to a handful of individuals, swamp near Bakersfield in the 1870s and Henry Miller who owned the San Joaquin valley at the time, decided to keep them secret and letting them breed.

[00:49:43] And since then, they’ve been, re-introduced in a lot of places around the state. So statewide there’s 5,000, maybe 10,000 Tulio, Docker established and various herds. And we have herds of 50 or more elk running around on Cody Ridge. And I think there’s about 500 in the Mount Hamilton. So the work I did on coyote Ridge and some work that was done in Vernal pools in the central valley with raising, established that, a moderate amount of grazing is actually really central for conserving biodiversity on 17 grasslands and in Vernal pools, which have a lot of endangered species too.

[00:50:26] And that was like the scientific basis for the formation of what became known as the California range, land conservation coalition, which came out of. Ranching community and the conservation community got together and decided to work on the 90% of things that everybody agreed on. And it’s become really powerful because there’s been a real turnaround on grazing management, because the California grasslands are what we call a novel ecosystem it’s a mix of native and primarily non native species that requires some amount of grazing to just remove the grasp bio mass.

[00:51:12] You go into areas that aren’t being grazed and that’s, the facts just starts building up. That, and it’s just been observed in a lot of places. So now grazing has taken . A really important role in grassland and range land management, because it’s really the only way to control the annual grasses over large areas.

[00:51:32] Fact that so much of California is being fertilized by small, means it’s even more imperative in places down wind of urban areas and large agricultural areas.

[00:51:45] Michael: That’s a really good point. The novel ecosystem concept is a reminder. We’ve already disturbed that ecosystem. And to, push back against that disturbance, there has to be additional management. And in this case, the management is

[00:51:58] through grazing.

[00:51:59] Stu: Yeah, there’s just no other way to control the grasses in a landscape scale that we’ve been able to figure out, you can’t burn on a regular basis. And even that just has transient effects and costs a lot.

[00:52:13] Michael: These are annual grasses,

[00:52:14] Stu: Yeah. There’s annual grass. Yeah.

[00:52:16] Michael: And I wanted to maybe tidy up a little bit on the broader implications of this discovery that, that nitrogen deposition was having this impact. I’m assuming that serpentine soils, aren’t the only soils that are subject to this problem. , Have you seen this sort of research and application In other soil types or other circumstances.

[00:52:39] Stu: . Yeah. So when I first got into it, one of my Stanford professors says how Looney directed me to a woman, ed Allen at UC Riverside. And. Turns out, not surprisingly UC Riverside is a major center for research in the air pollution effects on the ecosystems. So they have documented that the nitrogen allows annual grasses to get into the coastal Sage scrub.

[00:53:12] It has a lot of endangered species in it and transforms it via fire into kind of non-native weedy grassland. It’s really well known in Europe. That’s where they first discovered it. So they have studies showing, that the species loss from grasslands is directly proportional to the amount of nitrogen that’s being dumped on it.

[00:53:38] It’s getting more traction in the U S at least in the scientific community. There’s not been the kind of concerted conservation action like we have in Santa Clara county yet. I wish there were because it’s the at, in California, I’d argue in some parts of the state it’s as big or bigger threat than climate changes. It’s here, it’s now it’s been a long-term cumulative process and there’s a lot of imperil plants that depend on very open habitat and get overrun by the grasses. One of the side effects that I really like to try to get more attention on is that, single biggest allergy problem in California’s annual grasses.

[00:54:25] Yeah, they produce pollen and high fraction of the population is really miserable in the spring. The nitrogen deposition makes for more grass growth, which means more pollen. Even if the grasses can’t grow more because say it’s a dry year. They put all that. What we call luxury nitrogen in the making more pollen. So the tagline here is that nitrogen deposition really is something to sneeze at. And it’s on a global scale. The nitrogen cycle is probably, it’s more disruptive than the carbon cycle is. And we see the effects with coastal bed zones, all kinds of, air pollution, water, pollution problems, harmful algal blooms. And yeah, it’s really out of control and it hasn’t gotten the attention it deserves.

[00:55:17] Michael: yeah, the framing comparing it to the carbon cycle, is, a good one.

[00:55:22] Stu: Yeah. I think a carbon, Carmen, I’m just so sick. I hear it about carbon. Nitrogen is way more screwed up than carbon is.

[00:55:30] Michael: Well, There are so many of these instances too, where I think that in the media or in society at large, , we’ve been so focused on certain problem spaces. And, you know, I had a guest on the podcast a while ago. Talk about shifting baselines and. That’s sort of, I think what we’re talking about here in a way, so someone with your experience on the conservation side and the science side, I think you have a really interesting perspective.

[00:55:55] And I’m wondering if, you could just snap your fingers and magically impart one ecological concept to help the general public, see the world as you see it, what would that be?

[00:56:05] Stu: This came out of the Checkerspot work with the topography, that there’s a huge amount of climatic, variation and complex terrain. And there’s all these little nooks and crannies that will allow species to persist in landscapes far beyond. What their sort of general climate would allow. So the, there’ll be a moist north facing slope.

[00:56:37] That’s collecting a lot of water and that’s where the redwoods will hang on to the very end. And that climate is it really complex mosaic on the ground. That’s not necessarily well characterized by what we measure at weather stations. That’s one thing. The other one is that small is fertilizer. No, and it just says pervasive effects on ecosystems. And when you see that brown cloud hanging over San Francisco bay, Just need to realize it’s not just a hazard to human health. It’s a hazard to lots of rare species. And then I think the last one is bad. It’s just really important to get engaged. The science doesn’t speak for itself in the conservation world.

[00:57:29] You really have to push it out there, at work really hard, but it’s not well-rewarded in traditional scientific careers.

[00:57:37] Michael: I think those are all good ones and they all speak to the nuance as well. Do you have any upcoming projects that you’d like to highlight? Any papers coming, anything like that?

[00:57:48] Stu: On the nitrogen front, we’ve found that. The Springs coming out of the serpentine on Cody originally Talari hill are just loaded with nitrate. The atmospheric deposition is flushing right through the system because it’s so saturated. So we can actually measure that’s a project that kind of have enough data now to publish a paper on it.

[00:58:12] It’s pretty high priority. We’re doing a lot of butterfly and plant, re-introductions or population augmentations. So some of these highly endangered plants need a lot of help. So we raise seeds and our Creekside science conservation nursery, and we see them out into appropriate spots. And we’ve been able to save one species as little species San Mateo with ornament from extinction. Because of those efforts.

[00:58:41] Michael: Is that documented on the Creek side science website?

[00:58:44] I can point

[00:58:45] Stu: Yeah. We have some yeah. We have, we have a few news items about that.

[00:58:49] Michael: I’ll make sure to include some.

[00:58:50] Stu: Oh, another project that’s been a, not long-term ongoing one, a great link to it’s called the bay area conservation lands network. And this is like looking at 10 counties around San Francisco bay and seeing what lands protected, what it contains where are the priorities for acquisition and management. And it’s a, I guess I call it an implementation of this 30 by 30 idea, conserving 30% of the landscape by 2030. And we did the math and we discovered that we had. 30 by 20 that, there’s such a strong land conservation movement in the bay area. We’re like ahead of the curve compared to the rest of the country, which is a great place to be. And that’s a www dot bay area, land stock org.

[00:59:41] Michael: And if people want to follow your work, where can

[00:59:44] they go?

[00:59:45] Stu: We have a website, Creekside science.com. Keeping that up to date is sometimes a bit of a struggle because we’re so busy working on the rest of things, or it’s a lot of news and publications. It’s about time to do a major revamp of the website, but who knows when we’ll get to that.

[01:00:02] Michael: Okay. Well, I’ll be sure to include links to everything that you mentioned in the show notes. And before we go, is there anything else you’d like to say?

[01:00:10] Stu: I look forward to talking again and getting out in the field this spring.

[01:00:15] Michael: Alright, thank you so much for all the time you spent.

[01:00:18] Stu: Well, Thank you for putting together this podcast series. I’ve really enjoyed the other ones that I’ve listened to. And I feel really good about being a part of

[01:00:26] Michael: Okay, thank you for the kind words.

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