Listen to the Interview:

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Transcript:

Ross Chambless
Jacob Levine, welcome to the Wilkes Center. 

Jacob Levine
Thanks so much, Ross. Really excited to be here. 

Ross Chambless
Yeah, I’ve been excited to talk with you about your experience so far working at the University of Utah through the Wilkes Center, but also to learn about some of the research you’re working on right now. To begin with, can you just give our listeners a little bit of background about yourself? What got you interested in ecology? 

Jacob Levine
Absolutely. It’s a really good question. And I think my answer changes to it basically every time somebody asks me. But it’s sort of a long story, so I’ll try to keep it short. I, like all ecologists, like being outside. And so that was really the initial impetus, is that I wanted to do something that lets me be outside. 

When I started at the University of Berkeley, I was really interested in economics and so I wanted to find some way to sort of combine those. And it turns out that forestry, which is the study of the practice of growing trees essentially for timber production, but also for managing forests more broadly, was a good way to combine my interest in economics and in math and my interest in being outdoors. And my initial goal was really to be a forester, to be a practitioner. To go out and manage land either for timber production or for fire prevention or for a federal government, something like that. 

But my life really changed when I took a statistics course, which I think I’m the only person that’s ever happened to. Or maybe not, but the only person I’ve met so far whose life has been changed by a statistics course. And it was taught by an amazing ecologist named Perry de Valpine at UC Berkeley. And he really inspired me to be an ecologist because he just taught me about how rich and interesting the questions are in ecology, and how much work there is to do to understand how little we understand about it. 

And so, I really got fascinated by this and then I ended up going to Princeton for my Ph.D., where I worked with a couple of professors named Stephen Pacala and Jonathan Levine. No relation. And what I wanted to work on is really several things. I wanted to go to Princeton because Princeton is famous for its theoretical work, going all the way back to Albert Einstein, really, and famous physicists. And we don’t really think about theoretical work in terms of ecology. We often think about it in terms of physics. But the idea is that we want to describe, or discover really, mathematical equations that govern the dynamics of nature. In physics, there’s been a lot of work done on that, primarily in the late 19th century and early 20th century. And in ecology, it’s been a part of its history, but it’s becoming more and more a central part of it.

I wanted to use those types of techniques to answer really two key questions. The first is how do plants in nature coexist with one another? Why are there so many types of plants? What maintains the amazing biodiversity that we see when we go walk outside? And this is something that we really take for granted, you know, that there’s so many different amazing types of flowers, and trees, and shrubs. But it’s really a fundamental mystery why there are so many types. And so, this is fundamentally a theoretical problem because it’s asking what are the sort of underlying forces that allow different types of plants to live together and not out-compete one another.

And the second question I wanted to answer is, how will climate change disrupt those mechanisms that maintain biodiversity and thereby how will climate change affect the structure of plant communities in general?  

And so that’s one main thrust of my research. And the second main thrust is actually going back to my days at Berkeley working on Wildfire. And I’m specifically interested in how our management of natural landscapes affects the frequency, severity, and size of wildfires. And so, I spent a lot of time really looking at how industrial management, so timber management, going back to my days as a forester, affects how fires behave.

Ross Chambless
Okay, that’s really interesting. I love how you set that up as far as how you got into this. When you were in forestry, I imagine that you were doing some pretty active work. I mean, it seems like a pretty physical labor-intensive type of job. 

Jacob Levine
Yeah, absolutely. My first job in the field was I worked at a research forest where my job was going out with the chainsaw and cutting trees down or building fences, or also taking scientific measurements. But it runs the gamut. And I think foresters in general are really amazing people because they have to wear so many different hats. They have to be specialists in data science because they’re managing really complicated data over a large landscape. They have to be able to have great intuition and biological, natural history knowledge to understand the types of plants that they’re working with and how they respond to different treatments. And they have to be economists because they have to understand how to make these things profitable or how to deal with limited budgets when they’re applying this. And typically foresters are doing all this themselves. There can be some specialization, but they’re really a jack of all trades. And so, I really admire foresters as a profession. 

Ross Chambless
When you mentioned your interest in economics as well and sort of merging that with your interest in ecology, that also seems a bit unique perhaps?

Jacob Levine
Yeah. The joke I make is that economics and ecology are the same fields, but they’re optimizing different things. In economics, you’re always optimizing profits. And in ecology, you’re optimizing fitness, right? You’re optimizing the performance of plants. And the problems actually often look very similar. The math is often really similar between economics and ecology. And so, my experience in econ as an undergraduate really helped me do ecological research in…  not a unique way but approach it a little bit differently. 

And so, I can give you an example of how that sort of played into my work. Going back to this question of how do species coexist with one another? Well, I was really interested in understanding this problem in systems that are limited by water, where plants compete strongly for the soil water that was supplied by storms. 

And in these systems, what I found through theoretical work is that high diversity is maintained when there’s a tradeoff between species ability to grow really quickly, when there’s plentiful water and to sustain their growth in really harsh conditions. So really a tradeoff between drought tolerance and their ability to accumulate growth really fast. 

And that’s very similar to how we experience the world. There are tradeoffs everywhere. We make tradeoffs when we choose our careers. For example, I spent all this time learning how to write code and do math. But that means that I’m really bad at working on cars or around my house.  Whereas somebody who specializes in journalism has a lot of very different skills. You can’t do everything at once, right? And plants face the same sort of issues, right? You can’t be both extremely drought tolerant and a really fast grower. And that’s because you only have, as a plant, a certain amount of carbon that you can spend. 

And so, in order to become drought tolerant, essentially what plants have to do is invest their carbon in these specialized structures. So, when the soil is really dry — the atmosphere is really dry, there’s almost no water in the atmosphere relative to the amount of water in the soil. 

And so, there’s a really large gradient between the amount of water in the atmosphere, typically — obviously this varies a lot, but in drought conditions — there’s not a lot of water in the atmosphere. And so, there’s this big gradient between the air and the soil. And that means that there is a huge amount of tension actually inside plants in drought conditions. On the water column, there’s a continuous pipe full of water. Essentially, they’re very small bundles of pipes, these things called xylem, that are transporting water through the plant. And these pressures can reach sort of amazing levels. It can be more than the pressure in a scuba tank, for example. 

So, much like a scuba tank, which has to be really reinforced in order to withstand those pressures without cracking and allowing some leakage, plants also to withstand those pressures have to reinforce their internal pipes. And that costs a lot of carbon. They have to actually build thick walls around those elements that are transporting water. And because they’re investing that carbon in those what we call xylem walls, they can’t invest that carbon in producing leaves. And leaves are what get you more carbon. 

So, species which invest a lot in drought tolerance undergo this necessary growth cost much like me, by spending so much time on my computer and out in the forest, have a dearth of skills in many other areas, let’s say. I won’t out myself on what I’m bad at, but a lot of things. 

Ross Chambless
That’s a really interesting analogy. I love how you bring it back to how we make our decisions as humans, like decisions consciously or unconsciously. And some of it may be in our nature to just develop a certain way. And perhaps the same as with plants as far as why they grow in certain ways, depending on where they are? 

Jacob Levine
That involves a lot of evolutionary history and natural history. That is not my area of expertise. But it is also very fascinating how plants end up at the strategies that they actually exist. I’m more interested in what types of strategies can exist in a given area, and what allows those strategies to co-occur. 

Ross Chambless
Yeah. Well, you mentioned your interest in how plants coexist, and I want to bring it to one of your recent papers that looked at this topic of biodiversity maintenance and something that you describe as “competition for time.” Could you share a little about what that means? 

Jacob Levine
Yeah, I would love to. So, in those water limited systems, you have essentially a pulse of water delivered by storms, and then you have a long dry period, and then another storm. Now the length of that dry period can change. You could have storms right after each other. Or in other environments you might have a long time between each storm. But there’s some period in which there’s no active input of water. And so, in those periods after that pulse of water arise from a storm, the plants are competing for that fixed pool of water in the soil until the next storm arrives. 

And plants, when they compete for water, actually have sort of a unique response to limitation in water. So, plants have these little openings on their leaves called stomata. They’re like little mouths that they can actually open and close. And those stomata control the exchange of water and gases, carbon dioxide, oxygen with the atmosphere. And so, when those stomata are open, the plants lose a lot of water because of that really large pressure gradient. It’s also that gradient that allows them to bring water to their leaves for photosynthesis. 

But when they open them, in order to photosynthesize, because they have to be open to bring carbon into the plant, they’re also losing a ton of water. And so, when the plants become so water limited that they become worried about those xylem elements I was talking about earlier, what we call embolism, when they fail, they can actually allow oxygen into those little pipes. And that’s really bad for a plant because when you have air in there instead of water, you can’t move the water anymore. It basically makes that piece of its internal physiology nonfunctional.  And so, plants really want to avoid that. 

And so, to mitigate that risk, they’ll actually close their stomates when it becomes so dry that they start to risk embolizing. And when they close their stomates as a byproduct, they’re not getting any carbon.  They’re actually shut down. They are not photosynthesizing, they’re not using any water. But this, of course, is a big cost because they can’t just do nothing. They have to pay a generic carbon cost to keep up with their physiological demands. You know, much like we do. Any organism has to respire essentially, you know. 

And so, you get this really interesting dynamic where the plants, after a certain period, after that input of water shut down. So, they’re growing, they’re growing, they’re growing, they’re growing, and then they stop growing. And the time at which they stop growing is determined by this sort of lower limit of soil water level at which they can sustain growth. Once the water crosses that threshold, they shut down. 

Now, when you introduce competitors to a system like that, what happens is those competitors are also transpiring this with water. They’re consuming the same pool of water. So, they can actually cause that threshold to be reached earlier than if there were no competitors. And that causes the plant to shut down earlier than it otherwise would. And this has important consequences because it reduces their total amount of carbon accumulation over a given interval. 

And so, this really sort of unique dynamic which we discovered again through building models based on the physiology of plants, actually has really important consequences for how diversity is maintained in these systems. Because what it does is it allows species to, like I mentioned, specialize on essentially different parts of that interval between storms. 

Some species, those fast-growing, drought tolerant species I talked about, they get out and they do really well right after each storm and then they shut down. Whereas the species which have invested a lot of carbon in being drought tolerant, are able to continue growing for a long time. But they do so at a slow and steady pace. 

And so, you get this spectrum of strategies between these live fast, die young types and these much more conservative, risk averse strategies that are like, “I’m just going to hang here and go slow, but I’m going to be the last one standing” at the end of this period.

Ross Chambless
Yeah, That’s so interesting. You may have some of these different types of species of plants all living together and experiencing the same sort of fluctuations perhaps in wet or dry climates, or and changes of their climate. And they’re all going to react differently, it sounds like.

Jacob Levine
Yeah, they all have different places along this strategy axis essentially. And, you know, we can go out in the field, and I’ve done this with experiments using little annual plants in Southern California, and we find that they follow this pattern really well. The time in which they shut down is really dictated by the amount of competition in their neighborhood. 

Now, once we use this sort of discovery to understand how biodiversity is maintained in these ecosystems, we can then take that and start to understand how that biodiversity will respond to changes in climate and specifically changes in the patterns of precipitation. 

And you’re exactly right, Ross, that different species, different strategies are going to be differentially benefited or harmed by changes in precipitation patterns. And so, with that in mind, predictions about precipitation are sort of unintuitive with climate change. We expect there to be changes in total precipitation, but those predictions are really variable and uncertain. Some places are maybe going to get increases in total rainfall. Some places are going to get decreases. But we don’t really know how much that what the size of those sort of effects are going to be. 

And by contrast, we’re really confident that the sort of patterns in which precipitation is delivered are going to change. Basically, precipitation is going to become more extreme. And what I mean by that is storms are becoming less frequent, but when they do come, they’re becoming much larger. 

You know, we’ve all sort of experienced this in the places that we live, especially if you’ve been there for a long time. I’m from Southern California, where — this is a particularly extreme case — where the winter rainy season is becoming much more extreme and uncertain over time. And this is true all across the world. And so how does this affect biodiversity?

This is a question that I’ve been actively working on, so I don’t want to talk too much about it.  But I can give you a little bit of a spoiler. 

People have done experiments to try and figure this out before. They do these things called “precipitation repackaging” experiments. Essentially, how that works is they take the fixed amount of rainfall that falls in a given area. They capture all of it, and then they repackage it into fewer but larger storms. So, they maintain the total amount of precipitation. But now those storms are farther apart. But each one is larger because their total precipitation is constant. And then they’ll have control plots which just receive the sort of standard precipitation regime in that area. 

And what these studies have found is that actually this benefits biodiversity. And this is really sort of counterintuitive because when you have fewer but larger storms, you have this longer period between each one where there’s no water. And so you’d think that this would be really bad, especially for those drought tolerant species, because they lack specific adaptations to deal with that water stress. 

But some of the research that I’ve been doing now hints at a potential explanation for this result, which is that really what’s happening is that those larger pulses of water from each storm event allow even more drought tolerant species to sort of capitalize these extremely ‘get in get out’ strategies that are benefited by having a larger pulse of water.

Whereas if you think about an area having just a constant drizzle, that constant drizzle is going to be sort of suppressed all the time. But if you have these huge pulses followed by these dry intervals, then these species can sort of capitalize on that abundance of the resource and then sort of shut down and mitigate the losses over the long dry interval. 

Ross Chambless
Interesting. And this is partly because they’re sort of a community of plants working together, perhaps? Maybe that’s partly what’s helping?

Jacob Levine
They’re working together. I think that there’s certainly facilitation in nature. We see that all the time: pollinators are facilitators, mycorrhizal associations, or little fungi that help plants get resources from the soil. But the plants that I study are pretty antagonistic. On average, I would say they all want that water. And if they don’t get that water, it’s bad for them.

Ross Chambless
So, it’s highly competitive. 

Jacob Levine
Exactly. Yeah. But because they can divide this time between each storm, it’s not quite working together, but they’re sort of each finding their own little niche in this area. Niche is a word that we often use as ecologists. And it can be sort of vague. So I don’t want to hammer on that word too hard. But because the species have these different areas of specialization, essentially these different times that they specialize on, a lot of them can coexist. And also some of those strategies can be added when you alter the patterns of precipitation. 

Now, this is all preliminary work, so there’s going to be a lot more on this coming. But yeah, that’s the sort of stuff that I’m interested in working on right now. 

Ross Chambless
Okay, wow, very interesting. And just to clarify, when you talk about time, what intervals are we talking about? 

Jacob Levine
It’s fairly short timescales that I’m talking about. Yeah, the longest would be in sort of Mediterranean climates where you have a really strong winter season or rainy season, and then you have no rain for the next period. In that case you have several months over which this is happening, but in most places this is on the order of weeks.

Ross Chambless
And then specifically, with your research, you are looking at some specific sites? You mentioned Southern California, but are there more?

Jacob Levine

The experiment I just mentioned was done in Santa Barbara County in a beautiful area at the Sedgwick Natural Reserve, which is run by the University of California. And the ecosystem there is dominated, at least at this specific site, with really heterogeneous areas. It’s in the mountains, but it’s also sort of coastal. So you get a really large gradient of types of plants as you go up the hill. 

But in the specific place that I worked here, the area is dominated by these annual plants, which are sort of the most extreme example of this dynamic that I’ve been talking about. Again, this is one of those Mediterranean climates where you have a winter/rainy season, and then you have an extended dry period afterwards which lasts from about April until October or November. The plants all germinate during this winter/rainy season about the same time, and then they’re competing for that water over the course of the dry season until it becomes so dry that they have to shut down. 

But because they’re annuals, they don’t just close their stomates and wait for the next storm: they actually die. And as they’re dying, they convert their available biomass into seeds, and those seeds will then germinate again in the next winter rainy season and restart this cycle. 

So it’s a really amazing laboratory in which to understand whether this dynamic is occurring, because it’s this really extreme example of what we’re seeing. And we can really see it. You can watch a plant die really easily. It’s hard to watch a plant close its stomata because they’re very small, and we have instruments that we can use to go out and measure that. But here we can just say “How big are you?” each week. At some point you stop growing. 

Ross Chambless
Yeah. 

Jacob Levine
And in that site, it’s just one field. You can think of a basketball court sized area where I planted really different combinations of species competing against one another. The plants are at different densities in some control plots where we had no competitors, and then also some plots where we artificially removed rainfall to sort of mimic that mechanism of competition. We hypothesize the removal of water. 

And what we found is that these plants really respond in this way. When you introduce a lot more competitors, they shut down a lot earlier. When you remove water forcibly by just putting a shelter over their plot (so that we take all that water that would have fallen on the plot and move it elsewhere), they also shut down earlier in the same way. And this leads to a reduced overall performance. So that ‘competition for daytime’ dynamic is really happening. 

But we can also measure their specialization like I’m talking about. And we do see that they appear to follow this pattern whereby species which are drought intolerant are faster growing whereas species which invest in drought tolerance are slower growing. 

Ross Chambless
Yeah. That’s so interesting. I was just thinking about the process or the time it must take for you to see these changes play out, because it seems like you have to have a lot of patience, right? I mean, we’re watching these changes occur over weeks or months, right? I’m just thinking about how I can watch the plants in my own house. You know maybe I over-water that one, or this one is not getting enough. And I can see it’s gradually changing. But it takes a while for those changes to manifest in your samples, right? 

Jacob Levine

Yeah it’s especially important to know what you’re looking for. So with these annual plants, if you just look at them, it appears like they’re sort of slowly dying right there. They’re cementing over a long period of time. But what’s actually happening is that they’ve reached their peak. They’ve reached this threshold and they’re deciding to shut down because if they stay open, if they stay alive any longer, or if they respire any longer, their hydraulic system risks failing, and then they can’t produce those seeds which are the future of their species. 

So what you can do is measure their biomass. How big are they throughout the season? And what happens is that they grow very regularly, basically at the same rate, and then they stop growing. They level off and then that’s when that sort of senescence process takes over. And that happens over the course of several weeks or days, depending on the species. And in that period they’re basically producing seeds or they’re salvaging all the carbon from their leaves and anything that’s the most movable, and using that to make as many seeds as they possibly can. 

It’s the same thing with plants in non Mediterranean systems (not an annual plant system), so long-lived plants that are experiencing many dry periods instead of just one over the course of their life. It’s really not obvious that this is happening. And this is potentially one of the reasons why we haven’t been talking about this very much, if at all, in the context of water competition. You have to observe when the actual stomates on the plants are closing. And as I said, these are really small. So you have to go out there with special instrumentation that allows you to measure how open those stomates are at a given time. And only then can you see that they’re doing this sort of opening and closing.

Ross Chambless
Fascinating. Well, I look forward to learning more about this. It sounds like this is an ongoing research project right now? 

Jacob Levine
Yes, this is continuing. And yeah, as I said, right now I’m really interested in this: now that we understand some of the mechanisms that maintain that biodiversity in these systems, using that to project what these ecosystems are going to look like in the future.

Ross Chambless
Well, I want to make sure we save time to ask you about one other project that you’ve been working on. This project has to do with comparing fire severity on private industrial lands versus publicly maintained lands over time. I’m guessing you also did this work in California looking at forests? What have you been learning? 

Jacob Levine
Yeah, I would love to talk about that. So now we’re going to this sort of other focus of my research, which is on wildfire. When I was doing my PhD at Princeton this became sort of a side project, but it’s something that I’ve always been passionate about. Just because I grew up in California and fires are a part of life there, and especially during my university years, it started to become an increasingly large problem. So I was really interested in studying it. I joined a lab at UC Berkeley in the last year of my undergraduate and then stayed on for six months after I graduated, which is run by Scott Stephens and Brandon Collins, who are amazing professors there. 

What I was interested in understanding is what I mentioned at the beginning, this sort of interplay between our management of landscapes and forests, and how wildfires behave. With wildfire, one of the things that we’re most concerned about is that there’s more of them. The wildfires are bigger, but the wildfires are also more severe. And when we talk about fire severity, what we’re really talking about is the effects on tree mortality. 

How many trees die after a fire? You can go out and directly measure that if you’re out in the fields; you can say “There were this many trees before, this many trees after.” But doing that over a really large area is really difficult. And so we often use remote sensing to estimate the severity of fires using actual satellite imagery from before the fire and after the fire and some established sort of statistical relationships with mortality to estimate what the severity is. 

The reason we’re concerned about severity is because in a lot of forests, especially in California, the trees lack specific adaptations to fire for reproduction. So lodgepole pine is a good example of a species which is really adapted to this very fire. It has these cones that are sealed up by resin, and when they are burned, they pop open, and that allows them to regenerate. Now, the trees in the Sierra Nevada and the Klamath forests of southern Cascades forests of California don’t have these adaptations. Most of them don’t. So when you have a high severity fire, all the seeds are burned up, too. And when you do that over a really large area, you can actually change the type of landscape. You can change it from a forest to a shrubland or a grassland. 

That has a lot of important consequences for wildlife, for carbon, and also for us. We like forests as humans. They’re very shady. If you ever tried to walk through a brush field, you probably wouldn’t want to do it again, right? So I spent a lot of time walking through brush fields and also measuring these things with satellites and sort of a long-standing debate in California has been whether intensive management of forests is better or worse from a severity standpoint. 

This debate has become sort of acrimonious, honestly, and there’s a lot there. The Forest Service and timber companies have had  some level of disagreement over many things. There’s a very famous lawsuit over the 2008 fire, the Moonlight Fire, which created a lot of bad blood. So there’s a lot of blame being tossed around by everyone from environmentalists to scientists to practitioners to politicians. I wanted to really start to understand what types of management are beneficial or what are worse, not even getting towards benefits yet. “Which ones are worse?” 

What I did is just very simple. I looked at the severity of wildfires at a small spatial scale. How much mortality was there in a given 30 by 30 meter area on the ground? And I did this in 154 different wildfires that burned in California between about the mid-’80s through the 2010s (maybe to about 2015). Then I used a map of private industrial timberland versus federal land or governmental land. ‘Public land’ is what we call it. So that could be state parks, National Park Service, Forest Service, but almost entirely Forest Service. 

Ross Chambless
Yeah. 

Jacob Levine
And then I compared another category: small private landowners, nonprofit agencies like Nature Conservancy reserves, things like that. And what I found was actually not the result I was initially expecting: fire severity is significantly higher on private industrial land than on public land. And that’s even after controlling for the topographic differences between those landscapes or the weather differences. 

It’s really interesting, but it’s also a bit of a mystery. My intuition beforehand was that in actively managed forests, they’re removing a lot more fuels there, and it’s much more controlled. Whereas the Forest Service have had this because of fire suppression, removing fire from the system that is fire adapted. Because they’re not really able, for many reasons, to remove trees at the same level as a timber company. That’s not their objective necessarily. They have a lot more standing timber, and in their forests at least that’s sort of the intuition and what a lot of people thought. And so this result I thought was really interesting, but I really want to know why. 

We can hypothesize a little bit. Industrial timber companies tend to employ plantation strategies. They plant trees at pretty high densities. They’re all evenly aged, so they’re all about the same size, their crowns are touching. And there’s this really high spatial regularity. And fires like homogeneity because it means that they can, you know, build up a lot of momentum versus if the fuel source is sort of discontinuous, you get, you know, some build up and then it slows down. Maybe this is what’s happening. 

What I’ve been doing now is trying to use airborne LIDAR data, which is basically a very complicated laser setup. This is the same technology that’s on top of those self-driving cars you may have seen if you live in San Francisco or L.A., but it builds a very, very detailed picture of the forest. And so we have a data set of this from before some very large fires in northern California that burned in that Plumas National Forest. You may have heard of the Dixie Fire or the North Complex Fire. 

Ross Chambless
Of course, yeah. 

Jacob Levine
Those were really massive wildfires, and we have this amazing sort of ‘pre-fire image’ of the forest. We know where every tree that’s greater than four meters tall is. We know what its crown size is. We know the spatial orientation of all those trees. And so we can start to say, “What characteristics of the forest are most associated with high severity fire? And are those the ones that are more common on private industrial land?” Then we can start to get a mechanism. 

That’s really important because it allows us to start to develop some management guidelines, or guide management on how to improve this situation. One of the side effects of publishing this paper, which I’ve been very unhappy about, I would say, is that it’s been used as a cudgel against private timber companies in some instances, which is really, I think, unfair, and not really backed by the science. 

Ross Chambless
Yeah, that wasn’t your intent. 

Jacob Levine
No, of course not. It wasn’t my intent. It was also counter to what I thought was going to happen. So that’s been a bit frustrating. It’s been taken up by some environmentalists who have said “Stop thinning treatments! Don’t take any trees out of the forest!” 

And I’m like, “No, no, no, no, no!” Come on, that’s taking it too far. What I want to do is understand the mechanism. The “Why?” Then we can start to understand how to make this better. 

One final point is that just because the severity is worse on private industrial land, does not mean that the federal government is doing a good job managing the lands either. High severity fire incidents are increasing across all land types at very high rates, to the point where in these fires in the Plumas National Forest, I was talking about an average 60% high severity. So, 60% of the lands burned by those fires lost every single tree. 

That’s devastating. 

Just transitioning to the more laissez faire practices of the Forest Service isn’t going to correct that either. So we need to, as a society and as a society of scientists and practitioners and politicians, come up with a comprehensive plan that protects the timber industry because it’s really important. We all use timber for our lives every day, right? And it’s important for local economies that protect other aspects of the environment like wildlife and biodiversity and carbon, and also keeps people safe. 

Ross Chambless
Yeah. 

Jacob Levine
I think it’s a big challenge, but it’s been really exciting too, to sort of pick away at it and make my little contribution. 

Ross Chambless
Yeah, well, it seems like your work also could hopefully inform better forest management practices, right? Both for the public land and also the industrial side, just to help inform them as to how they can do this better. 

Jacob Levine
Yes, I think it’s definitely the case that we can start to build a picture for what types of forest you want to have if you’re worried about fires. But of course, that’s not the only incentive or objective in any of these landscapes. Forests are managed for many, many different things: for cultural things, for economic reasons, for natural reasons. So building this picture doesn’t necessarily mean the best thing for fire severity is to cut down every tree. Well, that’s true, right? But it’s obviously not something we should do. 

Ross Chambless
Yeah. 

Jacob Levine
But there’s some way to balance these different objectives that improves upon what we’re doing right now. And I think that’s what I am excited about working on. But I think there’s still a ways to go there. 

Ross Chambless
Yeah, great. Well, a couple more questions: I just want to mention that with this last study, the work that you mentioned, you anticipate having some more papers come out on that?

Jacob Levine
Yeah. So the paper that I’m talking about with the lidar data, understanding the mechanism of that previous result will be out in the near-ish future. But I don’t want to share the results of that quite yet. 

Ross Chambless
Understood. Just a couple more questions. So while we have you here, I guess this is more of a larger question, but what impact do you hope that your work will have on the world of policy, of forest management, of ecology? What motivates you, what gets you up in the morning? 

Jacob Levine
Oh, it’s a great question. I always struggle with this question because I think ascribing too much self-importance is always hard to do. You know, there’s a limit to the amount of benefit that our work provides as a scientist. And also, we’re often fundamentally motivated by our curiosity. And I think that’s true for me, as well as I want to know the answers to these big questions. 

But I do think that there are impacts of my work that excite me. We were just talking about fire and trying to improve and guide policy, especially in the Western United States, on managing wildfire and better balancing the different objectives of forest management with regards to biodiversity. 

I think that this is sort of a longer ways away, but one of the things I’m really interested in is feedbacks between climate and biodiversity. We know now that the biodiversity in a given ecosystem, the number of plants, the types of plants that are there, affects not just how many plants are there, but the actual function of the ecosystem, how much carbon is absorbed by the ecosystem, and also how much water is transpired by the plants in that ecosystem. 

That second one is really important because it can actually create these drought feedbacks. If the plants are actually putting less water back into the atmosphere, then the humidity drops. If you’ve been in a tropical forest, you’ve felt this yourself when the clouds open up and the sun comes out and it’s a glorious day and during the wet season, the air immediately becomes so humid. And that’s not because of some large-scale weather pattern. It’s because the plants are pumping thousands of gallons of water from the soil into the atmosphere. They’ve opened up their stomata because the sun is out and they’re now making the air more humid. And that can then create convective thunderstorms which then bring water back into the ecosystem. This doesn’t just happen in tropical forests, but it’s especially obvious there. 

When you harm that evapotranspiration rate, you can actually change both our physical experience of the world, how dry it is, which affects plants, crops, and rainfall. These things can have important feedbacks that affect our lives and the structure of ecosystems. If biodiversity is changing and it’s changing in a way that affects these important functions, we could get these sort of runaway feedbacks. We’re not really accounting for them right now in our projections for future climate. So one of the things I’m really interested in is finding ways to understand how those feedbacks might arise. And then if they are there and they’re strong, use them to build a better picture for what the world’s going to look like in the future.

Ross Chambless
Wow. So that’s great! I feel like I’ve gained a lot more appreciation for plants in this conversation. 

Jacob Levine
That’s right. That’s another general idea. I’m really motivated by plants. I think they’re really amazing. And there’s so much left to learn about the way that ecology works.

Ross Chambless
Absolutely. I’m always amazed by what more I’m learning about the natural world, but specifically plants. Well, finally, where can people learn more about your work, or if they want to read more about your research? Do you have a website? 

Jacob Levine
Yeah, I have a website. It’s levine-ecology.com. You can also follow me on Twitter. @Jacob_Levine or BlueSky at the same handle. I’m starting to be more active on BlueSky these days. I think most scientists are. I think those are the best places to find me. 

Ross Chambless
Great! And finally, what do you do for fun when you’re not researching? What do you do when you’re trying to relax? 

Jacob Levine
It’s a great question. I have a lot of different hobbies, but my favorite one recently has been canoeing. I was a big backpacker in California when I lived there. I don’t want to put shade on the East Coast by saying I was disappointed in backpacking when I moved there, but I found it to be very crowded. It was hard for me to find space unless I was driving 8 hours away, but I found that if I put a canoe in a river, it could be in the middle of Washington, D.C. and you get away from everybody. So I’ve been really getting into that and doing some whitewater canoeing and getting up to some cool places and seeing places I never would have seen otherwise. So yeah, I highly recommend getting in a canoe. 

Ross Chambless
I love that. That’s great. Well, Jacob Levine, thank you so much. I really enjoyed our conversation. 

Jacob Levine
Absolutely. Thank you so much for having me.