In Episode 80, Confluence talks with Rebekah Brassfield, a Systems Ecology student at 老虎机攻略. Brassfield describes her fascinating research into bumblebees and huckleberries, both crucial to Montana's ecological health. Along the way, we also discuss Brassfield's impactful mentors and the impressive research being done at Salish Kootenai College.
Story Transcript
Ashby Kinch: This is Confluence, where great ideas flow together, a podcast of the graduate school of the 老虎机攻略. I'm Ashby Kinch, Dean of the Graduate School. On Confluence, we travel down the tributaries of wisdom and beauty that enrich the soil of knowledge on our beautiful mountain campus.
Rebekah Brassfield: I've done so many bumblebee counts in my time, especially at huckleberry plots. I love the complexity of bumblebees. We have 24 species of bumblebee in Montana, the most of any other state. So there's so much diversity and they're just so fun to study. Huckleberries are the first spring bloom. Or one of the first ones. So right at the time that huckleberries are blooming, bumblebees are emerging from hibernation. So for bumblebees, huckleberries are a critical source of food for them.
Ashby Kinch: You just heard the voice of Rebekah Brassfield, a student in 老虎机攻略's Masters program in Systems Ecology, talking about bumblebees who are central to her research in the ecosystem of the Rocky Mountain West. On Confluence we like to highlight graduate student accomplishments. In anticipation of this year's GradCon, coming up Friday, February 24, we celebrate Rebekah as winner of 2022's Best in Conference Award for oral presentation in a STEM discipline. GradCon is hosted by 老虎机攻略's Graduate and Professional Student Association, providing an opportunity for graduate students to present their research and creative activity and compete for awards in 5 categories. With Covid restrictions lifted, we were able to meet in person in 2022, and will do so again in 2023. So come by the University Center on February 24th to have your gourd blown.
Rebekah won for her presentation "Predicting Huckleberry Habitat Using Species Distribution Models." Her real research focus is the dynamic role played by bumblebees as pollinators. We talk about how her interest in bees evolved, their relationship with vibrant huckleberry crops, and her work with students and research faculty at Salish Kootenai College. Welcome to Confluence, where the river is always with us.
Ashby Kinch: So I had the great pleasure of watching your talk at GradCon, and congratulations on winning one of the GradCon awards this year. What was that experience like this year?
Rebekah Brassfield: Yeah, I also did GradCon in 2021. So in the kind of aftermath of Covid, everything was virtual. In kind of the same fashion as this year, I recorded a video of my presentation to submit to the judges and that was the same thing that we did this year. And this year we got to actually present in person, which I prefer so much more. It's nice getting feedback from an audience and you know, when you're presenting you're looking for nods of acknowledgement and kind of that audience feedback on your speed or volume and you don't get that over Zoom. So it was so much more fun this year to actually be able to chat with people and present in person.
Ashby Kinch: Yeah and so that was in your session, you had some lively questioners. You had some high school students, which was kind of fun. They brought a totally different energy to the room. What about just the atmosphere of the conference in general? Did you get to go to some other talks and, and engage with other graduate students?
Rebekah Brassfield: I wish I took the time to go to other talks. I did not have much time this semester, unfortunately. But it was really nice this year because I felt like people were so much more engaged and people were, you know, chatting with each other in between sessions. And there were people congregating around food or drinks and that was just, it was so nice to be in kind of a conference atmosphere again, and feel the community around those events. Because that's a really big part of presenting your research is that connection afterwards.
Ashby Kinch: Absolutely. Yeah. And such a key part of graduate student life in general. And so you've got kind of an interesting background. You studied, biology in Nebraska. What brought you to 老虎机攻略? Why'd you apply to the Systems Ecology program?
Rebekah Brassfield: Yeah, so I finished up school in Nebraska and was very eager to leave the Midwest. I'm from Colorado, originally, went to Nebraska and just missed mountains and I missed outdoor activities. And there's not a lot of mountains in Nebraska, as you can imagine. So I moved to Idaho for work with the Forest Service and once that finished up I was like, you know, I want to go on to grad school. 老虎机攻略 is a couple of hours north of where I was living, so I think I'm just going to move to Missoula and I had driven through I think twice before I just picked up and moved and started applying. And it did take me a few years to actually get into the program. But I think those years were really important in honing in on what I actually wanted to study and what I wanted to do. Because I’m kind of a generalist. I just love all science. So it was nice to hone in on bumblebees and focus what I wanted to research on for grad school. Because I think that's so important, is you spend two years of your life researching something, you might as well enjoy it.
Ashby Kinch: Yeah. It better be something you're really, you know, invested in and have a passion for. So the Bumblebee thing came before applying. Where did that come from your background and interests?
Rebekah Brassfield: Yeah. I'm a botanist by trade. I've always loved plants and so working for the Forest Service, they hired me as a wildlife technician, but what they wanted was my plant expertise. And so I kind of grew to love the not-wildlife side of things: that plants were so applicable everywhere, and I could just take that wherever I wanted to go. And they started a pollinator survey while I was working there. And so we were capturing bees on flowers and I was identifying the flowers and then we'd send the bees off. But I saw a job posting for a field manager for Salish Kootenai College and so I applied for that job. They wanted skills and experience with plants because that's so important for pollinators, right? You need to understand the plants before you get the pollinators. So they took me on as a field manager and I absolutely fell in love with the system. I loved the complexities of bumblebees. We have 24 species of Bumblebee in Montana, which is
Ashby Kinch: Wow. Twenty-four?
Rebekah Brassfield: Twenty-four. The most of any other state. So there's so much diversity and they're just so fun to study.
Ashby Kinch: What are they specializing in—bumblebees—that creates that 24 niche spread?
Rebekah Brassfield: That's a great question, and that's kind of what I'm studying. Bumblebees have three different face shapes. So they have a short cheek, a medium cheek, and a long cheek, and that basically determines what kind of flowers they can pollinate.
So a short cheek bee can only pollinate flowers that have a short corolla length or basically how far they can reach to get to the nectar. So short cheek bees specialize on shorter flowers, long cheek bees, long flowers. And there's a lot kind of intermingling between those.
Ashby Kinch: Yeah. And I'm guessing the long ones can go short, but the short ones can't go long. And so they have to be really good in that niche in order to outcompete.
Rebekah Brassfield: Exactly. And for the most part, they're generalists. They kind of pollinate what they need to pollinate wherever it's accessible. But my research is specifically studying how they're acquiring the nutrients that they need. So do they specialize on one plant because it contains a specific element that they might need, or are they just kind of pollinating just to get pollen?
Ashby Kinch: Yeah. So, we're not going to be heading toward Brassfields's bees in the way that Darwin's Finches became a kind of model because it's not that hyper specialized where the beak shape and everything determines everything about the outcome. They're still going to always be cross-pollinating at some level. I used the metaphor of cross-pollinating.
Rebekah Brassfield: It was good! There are distinct species and actually my focus species was just listed as two different species. So I was studying what I thought was Bombus bifarius and they split it into two species, Bombus vancouverensis and then Bombus bifarius. So there's still distinct species amongst the bumblebees, but they're so generalized in a sense that they just kind of intermingle. And they have habitats, you know, there's some species that are at higher altitudes. There's some species that are only found in prairies. You know, they do still inhabit their niches. But I would feel comfortable saying they're pretty generalized.
Ashby Kinch: Yeah. I mean, speciation itself is kind of a funky science anyway, right? Because there are these gray areas and scientific communities will justly debate, you know, the boundaries. But speciation, for the kind of work you do, is helping you identify specific effects on a group of pollinators in one particular bioregion--the reciprocal effect they have on the plants that they're pollinating.
Rebekah Brassfield: Yeah. And there's a scientific consensus that pollinators are good. And so in our systems up here, this is kind of highlighted with huckleberries, where without pollination, you don't get berries. And we know this because huckleberries are very closely related to blueberries. So when blueberry crops are excluded from pollination, they produce smaller berries, fewer berries, and less viable seeds. And we're seeing similar things in huckleberry systems where, without bumblebees specifically, or bees that do something called buzz pollination, you don't get berries.
So they have direct impacts, especially up here. We don't see the early stages of huckleberries, we don't see the flowers. But we know the impacts of the flowers, which are those berries later in the season. Bears use them. We love to eat them.
Ashby Kinch: We do.
Rebekah Brassfield: I mean, huckleberries as a species are called keystone species. So they have impacts on many other organisms. And bumblebees are kind of that first step to…
Ashby Kinch: They're before, right? They're the step before that we maybe pay less attention to. Yeah. And so huckleberries, since you've now brought us to the huckleberries, we should talk huckleberries. Of course, anyone who's listening and is from Montana knows how important they are. It's a distinct and very interesting species, right? It's still impossible or has not been artificially grown. Right? So unlike blueberries, they're hard to replicate. Why is that, and what's unique about the biology that makes it distinct in this area?
Rebekah Brassfield: You know, I think one of the reasons why they haven't been cultivated is because they have a very specific habitat type, and we haven't quite determined what that habitat type is. We know they really like acidic soils. We know they like wet soils at high elevations. They're going to be impacted by snowpack and snow levels later in the season, especially as that melts and they're looking for spring blooms. They also reproduce primarily rhizomatically, which means that they shoot off clones in the area that they're in. So they have to be present first before distributing. Which kind of makes that cultivation difficult unless you are pulling it directly from the clone of a plant. And even then, I just don't think we've been very successful in understanding how to grow them from seed, so they have to be kind of transplanted. And the seeds are also kind of interesting because they're tricky to germinate. They're odd seeds. They don't germinate very quickly or very readily, and you would think that's their primary mode of distribution, you know, after bears eat them, you know, they deposit them somewhere elsewhere. Yeah. And those just don't seem to take root as much.
Ashby Kinch: And that is interesting because you see patches, they are intense and they're very interconnected when you find a good patch out there in the wild. You didn't mention aspect or sun exposure, but that's gotta be a factor too, right?
Rebekah Brassfield: Yeah. So when I was designing the species distribution model that I made, I was going to include aspect in the model. But aspect is really a proxy for a measure of how much moisture is in the soil.
Ashby Kinch: Got it. Got it.
Rebekah Brassfield: So a northern exposure is going to have inherently more soil moisture than a southern exposure that gets more sun.
Ashby Kinch: Because it's trapping that soil and it’s not gonna evaporate.
Rebekah Brassfield: So I included a measure of soil moisture in the model. Unfortunately that data was very coarse. So it was from the USDA soil data service, and you can pull that data and it's free to access. People can use it. But it's kind of estimations and interpolated values, so they're not very specific, and that ended up not being a great measure of where huckleberries were. And that isn't to say that it's not, because it very well could be, and it's just the data that I used for that.
Ashby Kinch: A, a little noisy relative to a direct measure. So have you done work where you've set plots up and done direct measures, bumblebee counts, that kind of thing?
Rebekah Brassfield: I've done so many bumblebee counts in my time, especially at huckleberry plots. Huckleberries are the first spring bloom, or one of the first ones, so right at the time that huckleberries are blooming, bumblebees are emerging from hibernation, which means for bumblebees, huckleberries are a critical source of food for them. It's, you know, the first source of pollen. It's the first source of nectar after they wake up from hibernation, and they need those renewed energy sources. So we've done all kinds of bumblebee captures and in huckleberry plots, that's pretty much the only thing that they're on is you just capture bumblebee after bumblebee on huckleberry. And there's a few other species, flowering, so I'm not going to say that it's exclusive. Right.
Ashby Kinch: But it seems like there's a heavy concentration there. That's so interesting. In the age of global warming to think about the queuing there--the cross-queuing. So their hibernation queues aren't related to huckleberries. It's corollary rather than a direct causation.
Rebekah Brassfield: Right. And that's called a phenological mismatch is when there may be a potential mismatch in the timing of when bumblebees emerge and huckleberries flower. And that applies to all sorts of organisms from the timing of bird migration to the timing of leafing out for trees.
There’s this kind of transition—especially as we enter an age of warming springs and changing in the timing of our seasons—there may be a time when bumblebees are emerging later than flowers, or flowers are blooming later than bees need. And that hasn't been totally studied yet because we're still understanding what influences those two cues. Is it temperature? Is it sunlight? Is it snowmelt? It could be any one of those.
Ashby Kinch: Yeah, but we're pretty sure they're not queuing each other.
Rebekah Brassfield: Right.
Ashby Kinch: But they're picking up cues from the same ecosystem and so, so maybe they'll just adjust that matching over course of time.
Lots of people here at 老虎机攻略 are studying different aspects of that, right? So Scott Mills's lab is looking at things like ptarmigan, when they're feathers change based on the snowpack. But there's nothing like that quite yet for this area. Plus it's just massively widely distributed. It would be kind of hard to study.
Rebekah Brassfield: Yeah, and I would love to do that research. We have the times of when we first see huckleberries bloom. Salish Kootenai College has been doing this research into phenology since 2015, when they started putting out trail cameras facing huckleberry plants, and they took pictures of the huckleberry plant at 8:00 AM and then probably 4:00 PM, early in the season, to determine when the first date was that they leafed out that they got their first blooms, that they got their first berries. That whole sequence of events they have pictures of. And so they have really good data going back that far and I would love to do that research, kind of diving more into what causes those timings.
Ashby Kinch: Yeah. That's fantastic. You've mentioned SKC a couple of times Shout out to them. I also wanted to talk about that a little bit. We have this ongoing and developing relationship. So for listeners who aren't familiar, this is a four-year tribal college that is offering an expanding array of degrees. They're growing really actively and doing incredible science research, often grounded in tribal values, grounded in tribal traditions and histories. And that camera study that you're talking about strikes me as just so perfectly tuned to a tribal perspective. Right. Because of course, the Salish, Kootenai, and Kalispell people have been doing that for centuries, going back, paying attention to the signs on the land. And so that study sounds creative and innovative, but in a way it's kind of building off of deep Indigenous tradition.
Rebekah Brassfield: Absolutely. And working for SKC, I really fell in love with this holistic approach to science. And growing up in Western science, there's this no-nonsense, you keep things serious, you stay impartial as a scientist. And going from that into the tribal and Indigenous values that kind of inform what SKC does is a really beautiful interaction of, all seasons and timings and, most importantly, humans interwovenness with that process. And I learned that, I learned so much through my time and, still working there, I've just learned so much about how those values are very distinct between Western science and Indigenous science.
Ashby Kinch: But maybe growing together.
Rebekah Brassfield: Hopefully.
Ashby Kinch: I love, you know, to hear about young scientists working from the beginning and having that in mind, that it's important to grow those models back together. Since you've been a graduate student, you've done some work up there as well, mentoring undergraduate students I think it was?
Rebekah Brassfield: Yes, I've been involved with a National Science Foundation research experience for undergrads. That was what I was originally hired to do, was be a field manager for their REU each summer. And I fell in love with the process. I love working with undergrad students on the process of science and understanding how to ask research questions. What makes a good research question? What is doable in a summer?
Ashby Kinch: What's practical? What can you kind of say: “I've got this limited amount of time. What can I accomplish?”
Rebekah Brassfield: Exactly.
Ashby Kinch: Yeah. And an undergraduate needs that kind of mentorship, right? Because science is such a big, intimidating thing. But you're trying to help them break it into a manageable thing that they can accomplish in a shorter space of time.
Rebekah Brassfield: Exactly. When I first got into science, I fell in love with it because I realized that this was the place where I could ask all the questions I wanted. And I had a professor at the time who really encouraged me to ask all of those questions. And up until that point, nobody had encouraged me to do that within my science classes. It was kind of a: “here's the lab. Do the lab. Turn the lab in.” But I never understood the process. And so once I did, I was hooked. I just love the, the fundamental part of science, which is just curiosity and examining what you don't know. And just experiencing things, I guess.
Ashby Kinch: This is hitting on so many things that are so important to this podcast and what we like to elevate: mentor relationships and how important it is for a mentor to open up a new avenue for an undergraduate. And then, in your case, to turn around and give back. And so many of our graduate students on campus do that. You know, they run labs and they recruit those undergraduate students and they play that really important role in the middle between the research faculty and the undergrad to kind of translate that experience of science down into the, the actual activity, the thing itself, and to keep that curiosity rolling.
So what's next? I know you're close to finishing. So you have the summer, you're gonna be working on some research and then finishing in the fall. Where are you headed after that?
Rebekah Brassfield: Yeah. This GradCon is one of my two GradCons where I made my own model and I've had one modeling class. And I did all of my models based on independent questions and interests and so I absolutely fell in love with the process of modeling and especially ecological modeling. I just think it's such a powerful tool that if we can practice harnessing that, we can inform so much science. So I would love to get into the field of ecological modeling and I would love to do that at 老虎机攻略 or with private companies that are looking to do that for conservation reasons or, you know, to inform larger scientific questions. That's really, I think, where my passion is moving.
Ashby Kinch: And is that more graduate education? Or is that just hanging out a shingle and starting to work as a consultant or work as a researcher on existing projects?
Rebekah Brassfield: I would love to get a PhD. I've always wanted to be a doctor for whatever reason, so I would love to continue my education. But I think I need a break after grad school to take some time off and reorient myself and just get some time to once again, kind of hone in on what my interests are within modeling now. Because I've changed a couple of times through my career, so honing in on what I'd like to model specifically.
Ashby Kinch: Yeah. Well it's a marathon, not a sprint. science will be with us, right? You can go break away and then you can kind of find your way back when it's time.
Rebekah Brassfield: Absolutely.
Ashby Kinch: Thank you so much for joining us on Confluence, Rebekah.
Rebekah Brassfield: Thank you for having me.