Past Highlighted PPE Members – Plant Population Ecology

Early-Career PPE Member of the Month – February 2019

Charlotte Brown

Charlotte Brown is a Ph.D. candidate in the Department of Biological Sciences at the University of Alberta, where she works in the lab of James Cahill. She received her B.Sc. from the Dalhousie University and was a PPE Student Travel Award winner in 2018.

PPE: What’s the focus of your dissertation?

I look at how plant size can affect species interactions and community assembly through size-asymmetric competition, where larger individuals gain a disproportionate amount of resources relative to their smaller neighbours. Despite size-asymmetric competition being well studied within plant populations, the role it plays in plant communities is just starting to come to light. I examine size-asymmetric competition in a community context to determine what resources drive it, whether all species are equally susceptible to it, and the consequences of it and size inequalities in community assembly.

We are finding that despite what was previously believed, competition for soil resources is typically size-asymmetric, species vary in their vulnerability to size-asymmetric competition such that small individuals are not always losers in these interactions, and the inclusion of size inequalities, which are typically the result of size-asymmetric competition, can improve estimations of diversity-productivity relationships by 30%. My next steps are to determine the relative role of size inequalities and size-asymmetric competition in other aspects of community assembly and larger ecosystem processes such as productivity and stability.

PPE: Where do you hope to take your research in the future?

I am interested in the mechanisms and consequences of plant-plant interactions, specifically in the context of plant community assembly. In the future, I hope to focus on the dynamic responses of plants to their environment and neighbours. As a member of the Cahill lab, I have gained an appreciation of a wide range of plant behaviours through experiments conducted by my colleagues. Most natural environments of plants have species turnover and environmental heterogeneity and I am excited to apply what has been learned about plant behaviour to understand plant-plant interactions in these ever-changing environments and how these interactions scale up to impact broader ecosystem functions.

Early-Career PPE Member of the Month – December 2018

Becky Dalton

Becky Dalton is a Ph.D. candidate in Ecology at Duke University in the lab of William Morris. She received her B.A. in Environmental Studies from the University of Pittsburgh. Here she tells PPE about her current work, experience as a NSF Graduate Research Intern, and her postdoctoral plans.

PPE: What’s the focus of your dissertation?
I use experiments, observational data, and demographic models to examine the relationship between plant phenology and interspecific interactions for biotic (pollinators) and abiotic resources (light and water) at the Rocky Mountain Biological Laboratory. Two early-flowering species, Claytonia lanceolata and Mertensia fusiformis have been increasing in floral temporal overlap as a result of early snowmelt. In a series of experiments, I assessed phenology, pollinator visitation, and vital rates of these two species. I found that although these species do share pollinator species, they do not compete for pollinator services. Additionally, the presence of neighbors increases the probability survival. In another experiment, I found that the beneficial effect of neighbors is not due to water stress amelioration. I am now working to understand how neighbors may buffer population growth rate of these early-flowering species under future climate change. The results from this research have the potential to help us predict how climate change may affect species coexistence in the future.

PPE: You spent a semester at the Northeast Climate Adaptation Science Center. What was that experience like?
I had the opportunity to participate in NSF’s Graduate Research Internship Program, which enables graduate students to work in federally funded research labs for part of their PhD. I joined Dr. Michelle Staudinger’s phenology research group at the Northeast Climate Adaptation Science Center. I have since been working with her and collaborators to understand environmental drivers of adult alewife migration in Massachusetts. As a plant ecologist, I had a lot to learn about marine organisms. After spending time with a research group that thinks about similar questions in a different system, I was able to reframe my own understanding of phenology and climate change. In addition to broadening my understanding of ecology, I learned how basic and stakeholder-driven research differ. Up until the time that I participated in the NSF GRIP, I only worked in academic institutions. The opportunity to learn about stake-holder driven research gave me a better foundation when thinking about my future career in research.

PPE: What do you plan to do after completion of your graduate work?
I am really excited to start the Synthesis Postdoctoral Fellowship at the Rocky Mountain Biological Laboratory in May. I will be working with Drs. David Inouye (University of Maryland), Nora Underwood (Florida State University), Brian Inouye (Florida State University), Rebecca Irwin (North Carolina State University), and Aimée Classen (University of Vermont). We are leveraging the numerous long-term datasets at RMBL to understand the ecological and evolutionary consequences of phenological shifts.

Highlighted Young PPE Member of the Month – June 2018

Karin Burghardt

Karin Burghardt is a Smithson postdoctoral fellow at the Smithsonian Environmental Research Center. She received her Ph.D. from Yale University in 2016 and will be starting a faculty position at the University of Maryland this fall.

PPE: You have a new paper coming out in Journal of Ecology. Tell us about the research question and what you found.

KB: This paper emerged from my dissertation work. Early on, I found that if I grew the same goldenrod genotype in different soil environments the clones would have a different response to grasshopper herbivory. Essentially the same genotype would tolerate herbivory in low nutrient environments but induce resistance in fertile conditions. One might imagine that the changes in structural and chemical components of the vegetation that deter herbivores might also hinder decomposers (so-called “ghosts of herbivory past”). As a result, we performed a follow-up study highlighted in this paper to trace whether these context-dependent plant defensive behaviors in the green leaf tissue also cascade to alter microbial decomposition of the senesced leaves from the plant at the end of the growing season. In other words, can we detect a differential “ghost of herbivory past” across a nutrient gradient?

It turns out we can. Microbes decomposed herbivore-induced tissue 20% more efficiently than control litter at low nutrients (where tolerance of herbivory occurred) but 11% less efficiently than control litter at high nutrients (where defenses were induced). These results mirror the results for herbivores feeding on the same tissue and we can trace the decomposition differences to plastic changes in key green leaf traits post-herbivory. Basically, if a grasshopper finds a plant unpalatable so will the microbes.

What I found fascinating about the project is that it really forces you to look at a very familiar landscape in a different way. Old-fields are colonized by goldenrod seeds soon after abandonment from agriculture. These individuals then spread clonally through deciduous ramets each year, resulting in large patches of genetically identical goldenrod clones. So, what seems to be a homogenous expanse of goldenrod in a field really is a mosaic of genotype patches that are then layered with patches of differential plant traits shaped by soil fertility and the uneven distribution of herbivory. It is this dynamic mosaic that will shape decomposition dynamics in the field come fall. Since goldenrod can comprise up to 90% of the cover in old-fields for a period of extended dominance before woody plants encroach, I imagine that whatever is happening with their decomposition dynamics has an outsized role in current ecosystem processes rates and possibly shapes the future trajectory of the whole field.

PPE: Do you have next steps planned to continue this work?

KB: I am still wrapping up publications from the last phase of this project which was a large-scale, raised bed mesocosm experiment testing how these herbivore/plant/soil dynamics play out over a full 3 years of goldenrod growth. So, stay tuned for that, but otherwise I am not currently working in the old-field/goldenrod system. However, the idea that plants can dynamically respond to both herbivores and environmental conditions in ways that then cascade out to shape both communities and ecosystem processes continues to be an organizing conceptual framework within my current post-doctoral work. At the Smithsonian Environmental Research Center (SERC), I am using a manipulative tree diversity experiment (BiodiversiTREE) to investigate how tree planting arrangement alters insect herbivore host use patterns. I am also partnering with collaborators to connect the caterpillar community I find on the trees to leaf defenses/traits, leaf endophyte communities, and mycorrhizal communities.

PPE: You’re starting a new faculty position at the University of Maryland this fall – Congratulations! What are you hoping to pursue there, and what could potential students and postdocs expect in your lab?

KB: Yes, thanks! I am thrilled to be starting in the Entomology department at UMD in August. The lab is going to be focused on using an empirical understanding of ecology and plant/insect interactions to figure out ways to support insect biodiversity and optimal ecosystem processes within human-managed landscapes. Insects get a bad reputation, but they are these incredibly important components of functioning food webs as predators, prey, and pollinators (in addition to of course being beautiful and fascinating creatures). Many species also don’t require huge, unimpacted landscapes to complete their life cycles so there are opportunities to support biodiversity even within patches as small as an individual yard on up to the scale of a managed forest.

I envision the lab starting with two broad project areas. First, a continuation of the work at in BiodiversTREE to include above-ground predators and parasitoids as well as below-ground communities and nutrient cycling. This tree experiment is essentially an agroforestry experiment comparing monoculture to polyculture planting regimes and there are lots of opportunities for projects as the forest grows. Second, with some area collaborators, I am developing projects within a network of homeowner’s yards focused on how landscaping decisions such as leaf litter removal and mulching alter herbivore and predator populations as well as nutrient cycling. Many lepidopterans/hymenopterans overwinter in the leaf litter or just beneath the soil surface so continual removal of litter and addition of thick mulch could have large consequences for pollinator/herbivore populations. I’ve done quite a bit of work in the past considering how planting native vs. non-native host trees in yards impacts herbivore and bird populations. However, I think something equally crucial and often overlooked is that these organisms have lifecycles that span the entire year. Thus, in managed landscapes we are potentially providing resources for part of their lifecycle, but then mulching/bagging/trashing them as they overwinter, possibly creating population sinks in developed areas.

I am not exactly sure what new interactions and dynamics we are going to find in either of these systems but I am excited to find out! I am currently recruiting for the lab so if either of these avenues of research gets you excited feel free to contact me with your research interests or check out my website for more information.

Highlighted Young PPE Member of the Month – January 2018

Georgia Fredeluces (Hart)

Georgia Fredeluces (Hart) is a PhD candidate in the Tamara Ticktin’s lab in the Department of Botany at the University of Hawai`i at Mānoa. Her research supports conservation of native plants and their associated cultural roles through work that integrates population biology, ethnography, and education. Georgia has received both a NSF Graduate Research Fellowship and a Fulbright Research Award in Human Ecology.

PPE: You recently published a paper about the use of introduced plants in traditional medicine (PLoS ONE 12(9):e0184369). Tell us about this research and its implications.

GF: This paper was born out of a class I took with the second author, Dr. Orou Gaoue, on theories and major hypotheses in Ethnobotany. At the same time, my Graduate Assistant supervisor, David C. Duffy, showed me a copy of a new publication from Ecuador on useful plants. When he showed me the new book, I got the idea that using this new resource, as well as the already published Catalogue of Vascular Plants of Ecuador, we could rigorously test some of the hypotheses in the field of Ethnobotany. It was also helpful that both Dr. Duffy and I are familiar with Ecuador and have lived there or have family connections. I was a Fulbright Grantee to Ecuador in 2004-2005 and I did ethnobotanical work as well as a project on plant succession in the high-altitude grasslands, or páramos. I actually volunteered to help on the project that resulted in the book mentioned. We therefore already knew several of the co-authors and could more easily reach out to collaborate.

In this case, we tested the Availability hypothesis, the Diversification hypothesis, and the Versatility hypothesis. These all relate to explaining the reasons why people chose particular plants for medicinal use. Some work has suggested that people are increasingly using introduced plants for medicine because they are more available, perhaps because they are weedy (Availability hypothesis) and that knowledge concerning native plants could be lost. Other people have suggested that the use of introduced plants is occurring in concert with the maintenance of native plant use, but simply broadens treatment options (Diversification hypothesis). We tested these hypotheses, and a few others, with a focus on the use of introduced plants in Ecuador.

We found that introduced plants were very popular for medicine (disproportionately high use). In explaining why, we found nuanced support for each hypothesis, suggesting that most of these factors may be operating in driving plant selection, but that other factors such as cultivation are also highly important in explaining trends, but not well integrated into the hypotheses. So, the work indicates some places for further refinement of theory. It also highlights the value and importance of cultivated and semi-cultivated areas for human health services.

PPE: Most plant ecologists don’t have much of a background in ethnobotany. How do you think ethnoecological knowledge would strengthen plant ecology research?

GF: Fundamentally, I think there are different and equally valid ways of understanding the world, including understanding and relating to ecosystems, or the world of nature. The more open a plant ecologist can be to alternative epistemologies, the stronger that scientist can be in understanding, critiquing and moving forward with their own way of knowing. I think a researcher needs to know the weaknesses and strengths of their field and their worldview in order to do their best work. Western science and Indigenous science have similarities and differences and each has strengths and weaknesses. The problem is that these knowledge systems are embedded in the context of colonialism. There is often an inherited sense of superiority or truth within western science that can often be passed along with natural scientific training. This doesn’t allow for the equal respect and reciprocity necessary for mutual understanding and collaboration across knowledge systems. The plant ecologist of western training may have the responsibility to decolonize their mind in the same way that we all bear the responsibility to eliminate sexist or racist bias that we have inherited through our culture or upbringing.

For people like myself, who are interested in interdisciplinary work across the natural and social sciences and across western and indigenous knowledge systems and ways of knowing, this process becomes even more critical. For me, the synthesis or collaboration across knowledge systems is not only healing in itself, but is also necessary for solving the major problems facing our world today. Climate change is a prime example. Indigenous peoples have key knowledge, experiences, research approaches and connection to climate change, that may be different from the mainstream and therefore hard for some people to accept on equal status to natural science approaches. Spirituality of any kind, I think, is a good way to make this connection or leap. Western natural scientists are often deprived of this spiritual component in their working life and openness towards spirituality could help to bridge western and indigenous worlds. I see any bridging as a healing process, and as a racial reconciliation process, that requires acknowledging power imbalance, white privilege, as well as past genocide and its persistent impacts. In other words, there needs to be a willingness to see and to see our connection to these issues, and second, a willingness to try to repair what has been done in small and large ways.

PPE: What advice would you give to students just starting in a Ph.D. program, especially if their interests span the natural and social sciences?

GF: Stay with your heart. More is possible than what seems possible. Many boundaries or walls that seem to be there can be overcome or ignored entirely. Think big and find a mentor or group of people who support you and share your vision and values. The culture of natural science is not always friendly to social science. You will need support to work through this and interpret the feedback you will receive because of your interest in social science and perhaps the higher value you place on elevating and giving back to community. If you are willing to be somewhat of a trail blazer, with all the challenges that go along with this, you can make a big impact. I would like to see the culture of academia move towards greater emphasis on direct social benefit and on real world problem solving. If you don’t have support for your values where you are now, find a new place, or a new person, or both. I also suggest attending society conferences that include people who share your interests and values. If you can, live with people who share your interests and values. Always take care of yourself and especially during fieldwork. It’s okay to be cautious and start small.

Highlighted Young PPE Member of the Month – December 2017

Josh Lynn

Josh Lynn is a PhD student in the Department of Biology at the University of New Mexico where he works with Jennifer Rudgers and Ken Whitney. Josh also received a PPE Student Travel Award to the 2017 ESA meeting in Portland.

PPE: What’s the focus of your dissertation, and what are you hoping to find out?
JL: My dissertation is framed to address: what role do biotic interactions play in limiting plant species’ elevational ranges? and can we predict the effects of these interactions on a species under a future climate? These questions have led me to employ a diverse suite of techniques, including ecological niche modeling, cross-range limit transplant experiments where I manipulated the competitive environment of focal alpine species, experimentally informed population modeling, and trait-based models of competition. All of this is aimed to predict whether or not alpine restricted species can remain “king of the hill”, as low elevation species encroach upslope with climate change.

PPE: What next steps are you hoping to take after this work?
JL: I’m still excited about the power of transplant experiments and creating “novel communities” to gain insight into the effects of the climate change on biota. I’m interested in trying to reassemble communities according to expectations of species’ range shifts with climate change, and using models to predict a priori the community dynamics. I’m also interested in investigating to what degree can we scale up individual physiology to predict population, community, and ecosystem dynamics.

PPE: What advice would you give to students just starting in a Ph.D. program?
JL: Read broadly, take a lot of math/statistics courses, and apply to as many funding opportunities as possible. One of the best parts of grad school, to start at least, is having the time to read. I took the time to read as many monographs (e.g. MacArthur’s Geographical Ecology, Hubbell’s Unified Neutral Theory) and theory papers as possible, to get a handle on the historic and current state of ecological theory. If you’re coming from a biology background that was light on statistics and general mathematics, I would highly advise getting that foundation in grad school. It will open up new research avenues and questions that you may not of thought of without that background. And finally, take this time to get experience writing grants. From small ones, like department scholarships, to NSF sponsored programs like the GRFP- The little grants pile and give you more experience to tackle larger grant proposals.

Highlighted Young PPE Member of the Month – November 2017

Aubrie James

Aubrie James is a PhD candidate the Ecology & Evolutionary Biology program at Cornell University, and her advisor is Monica Geber. Aubrie also received a PPE Student Travel Award to the 2017 ESA meeting in Portland.

PPE: You’re setting up a large field experiment this fall. What’s the focus of this project, and what are you hoping to find out?

AJ: I am really interested in how flowering plants coexist. To feed this interest, I study four sympatric species in the genus Clarkia (Onagraceae), winter annuals native to California. In this system, it is patently clear when you go out and look at multi-species Clarkia communities that each of the species tends to clump in certain areas in the community; I call these sub-sites, and I consider them an indicator of underlying spatial variation in the broader community. My aim with this experiment is to determine if spatial variation in a Clarkia community is related to variation in the Clarkia species’ competitive interactions. To answer this, I will estimate the competitive interactions of all four of my Clarkia species using data from over 600 experimentally seeded plots in one community. I have these plots set up so that I can estimate all pairwise competitive interactions in each Clarkia sub-site — that is, where each species naturally aggregates and is most abundant in the community. If I find the Clarkia competitive hierarchy is invariant with respect to sub-site, then it is unlikely that spatial variation (as conceptualized in this experiment, at least) is a major player in Clarkia coexistence. The converse is also true: if I find the Clarkia competitive hierarchy has a different structure in each sub-site, we can reasonably conclude that community-level spatial variation has an effect on Clarkia interactions and coexistence.

PPE: What next steps are you hoping to take after this work?

AJ: In the short term, Gaurav Kandlikar (UCLA) and I just submitted a proposal for an Organized Oral Symposium at ESA 2018 on this topic. The working title is “Examining the Role of Spatial Variation in Maintaining Plant Community Diversity.” I’m excited about it and I’m really hoping it gets accepted — if it does, readers who are interested should check it out.

I also suppose I have to finish ye olde dissertation at some point, right? This is the last experiment of my dissertation, so professionally, I am hoping to start applying for post-docs in 2018-2019. This is both a) utterly reasonable and b) completely nutty to me.

Finally, I have a few things related to this particular piece of my dissertation that I am excited to dig into. The experimental nut I really want to help crack is to figure out how to reliably measure seed dispersal kernels. On the analytic frontier, I’m really excited about the idea of marrying coexistence theory and Bayesian approaches. And in theory land, I want to continue to build out our understanding of plant coexistence to accommodate indirect interactions – especially interactions via shared pollinators.

PPE: What advice would you give to students just starting in a Ph.D. program?

AJ: First: everyone you meet in grad school will offer you advice – take what you need and leave the rest.

Second: culture a solid understanding that you have value outside of your productivity; beware prescriptions for success; wear a watch; minimize your ego; meditate on limits; always remember that science is a human endeavor; cherish your loved ones; take a course in probability theory.

Highlighted Young PPE Member of the Month – June 2017

Rachel Spigler

Rachel Spigler is a plant evolutionary ecologist and an assistant professor in the Biology Department at Temple University.

PPE: You recently were awarded a NSF grant — congratulations! Tell us about the project and what you are investigating.

RS: The project will investigate the demographic consequences of self-fertilization across contrasting competitive contexts. Motivation for this work was sparked in part because of the repeated patterns of increased selfing rates in fragmented and disturbed plant populations. Perhaps because we know so well the negative effects of selfing on individuals’ fitness due to inbreeding depression, it seems self-evident that these effects would scale up to negatively impact population growth. Yet, this is an oversimplification, and glosses over what I think are likely to be fascinating and complex ecological and genetic feedbacks that arise with variation in selfing rate when one considers variation in the strength and timing of inbreeding depression across life stages, the stages most important for population growth, and the intensity and nature of intraspecific competition, all of which can depend on interspecific competitive context. The goal of the proposed research is to identify and to untangle these potentially critical interactions by carrying out a demographic experiment using the biennial Sabatia angularis as a study system.

PPE: How does this work build on your past research?

RS: The idea for this project actually germinated (ha!) while I was working on my PhD thesis on the reproductive consequences of small population size. From that work and work since on Sabatia angularis, I had determined that selfing rate can be variable among S. angularis populations, inbreeding depression may be expressed at almost all life stages but its strength across stages is variable, selection against homozygous, putatively inbred individuals occurs in wild populations, and both intra- and inter-specific competition were strong. I’ve also performed studies on pollen limitation and reproductive assurance in this species, which indicated that selfing rate can vary independently from seed production. What has been missing for me was the demographic component – what life stages are most critical for population growth of this species and what are the critical ecological and genetic drivers of its population dynamics? I’m excited to have the opportunity to work on these questions.

PPE: You have a strong interest in outreach in ecology. Why do you think this is important, and what have you been able to do to contribute to it?

RS: I think it is easy as academic biologists to get buried so deep into the details of our specific scientific niche that we forget (how) to communicate the big picture to non-scientists, especially kids. One way I’ve tried to contribute to outreach since starting my position at Temple University in Philadelphia is by joining up with local summer camps and leading activities about floral form and function, pollination, and plant and pollinator diversity.

Highlighted Young PPE Member of the Month – March 2017

Matt Tye

Matt Tye is a Ph.D. student at Uppsala University in Sweden. He received his M.S. from the University of Central Florida where he studied the effects of disturbances on plant populations.

PPE: You recently published a paper examining how multiple disturbances can interact to affect plant demographics. What was the motivation for this study, and how do think your results can inform plant population ecologists?

MT: The role of large disturbances, particularly fire in the case of our study system, has increasingly been recognized as extremely important to maintaining biodiversity and stable population sizes in many species. However there are relatively few ecosystems that experience only one type of disturbance, especially when anthropogenic disturbances are considered. So we wanted to see if our conclusions about the role of fire were altered by interactions with other known disturbances in the system. We found that the effects of fire actually interact fairly strongly with both herbivory by deer and habitat type. I hope these results will help convince plant population ecologist to consider multiple environmental drivers simultaneously where possible. I also hope it will give land managers a greater ability to design management regimes that maximize species persistence.

PPE: Are you taking this work in new directions?

MT: Yes, albeit in a far different ecosystem. I am currently working on mire orchids in central Norway to determine how climate, pollination rate, mowing by humans, and a few other factors interact to affect the life history of different orchid species. The longer time period of a PhD has given me the ability to explicitly test some of these interactions with designed experiments in addition to relying on long term datasets. That combined approach has opened up new opportunities for analysis that wouldn’t be possible just from observational data.

PPE: You’re from the U.S. and got your MS at UCF before starting your PhD work in Sweden. Do you have advice for students looking at international graduate opportunities? What advantages and challenges have you encountered?

MT: I would say to potential students looking at moving abroad to simply be prepared for the changes that moving to another country brings. Between adjusting to a new country, culture, language, etc. all while trying to start working on a new research system, it is very easy to get overwhelmed at first. After the initial adjustment period the largest challenge has been simply keeping up with the all the paperwork and administrative issues that come with being an immigrant on a student visa.

I think the major advantage of moving abroad for a PhD is being exposed to a new system and new way of doing research and teaching. By being able to compare and contrast what works and what doesn’t work about both the American and Swedish systems, I feel like I have markedly improved both as a researcher and an instructor.

Highlighted Young PPE Member of the Month – November 2016

Nicole Rafferty

Nicole Rafferty is a Research Associate in the Department of Entomology at Washington State University. She received her Ph.D. from University of Wisconsin-Madison and has held postdoctoral positions at University of Arizona and University of Toronto. In January she will be starting a faculty position at University of California-Riverside.

PPE: You have a new paper in Journal of Ecology that investigates how evolutionary history affects flowering phenology shifts. Can you tell us about the main findings and how they advance our understanding of climate change effects on plants?

NR: Climate change is causing shifts in the timing of flowering for many plants around the globe. In this paper, we combined data on these shifts from locations across the Northern Hemisphere to test for phylogenetic signal – the tendency for closely related species to have similar traits. The main findings are that shifts in flowering phenology show signal, with both the direction and magnitude of shifts shaped by selection, rather than evolving according to drift. By compiling data across plant communities and testing multiple models of trait evolution, we gained the understanding that flowering phenology of close relatives is likely to shift in similar ways, ways that reflect selective optima.

PPE: What’s a project you’re currently working on?

NR: I have an ongoing project that focuses on testing for local adaptation in wildflower populations at the Rocky Mountain Biological Lab, with the ultimate goal of understanding how joint phenological and distributional shifts affect plant-pollinator interactions. Many plants in this subalpine community have shifted their flowering times, and some bumble bees have moved up in elevation. The project involves reciprocal transplants of wildflowers and observation of bumble bee visitation along elevational gradients.

PPE: I know you’re about to start a faculty position at UC-Riverside (congratulations!). What opportunities do you have for students, and what do you hope they can gain from your lab?

NR: I’m thrilled to be starting as an assistant professor at UC-Riverside and am very much looking forward to building a lab group. I plan to recruit two Ph.D. students to begin in fall of 2017. I would especially like to mentor students with interests in plant ecology, plant-pollinator interactions, or phenology, and there are opportunities for fieldwork at the Rocky Mountain Biological Lab in Colorado and the University of California Natural Reserves. I aim to build a diverse, supportive group where scientists at all stages, including myself, can give and receive constructive criticism. I hope my students will gain an appreciation of field ecology, the skills to communicate their findings effectively, and a desire to mentor and teach others as they go on with their chosen careers.

For more about Nicole’s research and opportunities in her new lab, check out her website!

Highlighted Young PPE Member of the Month – October 2016

Anny Chung

Anny Chung is a Ph.D. candidate in the Rudgers Lab at the University of New Mexico. She received her A.B. in biology from Washington University in St. Louis. Earlier this year Anny was awarded a NSF-DDIG to support her work on competition and coexistence in plant communities.

PPE: You recently published a paper on how plant-soil feedbacks affected competitive interactions between two grasses. Tell us about that project and your conclusions.

AC: Knowledge that plants, especially in monoculture, build up pathogens that then limit their own success has existed for a while. That’s the conventional wisdom behind crop rotations. And in the past few decades, experimental evidence has built up that demonstrated this feedback between plants and microbes is also important in natural communities, and could be a mechanism that explains coexistence among plant species. However, as we know from basic competition theory and modern coexistence theory, mechanisms only lead to stable coexistence when it causes species to limit themselves more than they do their competitor, which has not been tested for plant-soil feedbacks. So in this project, we tested this hypothesis in a greenhouse experiment. We competed two grass species in different relative frequencies and densities with added soil microbial inocula from field monocultures of each species and biological soil crust communities. We found that negative feedbacks between the dominant competitor and its rhizospheric microbes magnified self-limitation, which suggests that plant-soil feedbacks could be important for coexistence in this system.

PPE: Are you hoping to ask other questions in this study system in the future?

AC: Definitely! I am close to wrapping up an experiment that focuses on the same two grass species, and measures their plant soil feedbacks in the field. From long term data, we know that across space, these two species vary in how frequently they displace each other or maintain stable co-occurrence through time. My field experiment aims to investigate whether varying strengths in plant-soil feedbacks underlie different patterns of stability in these co-occurring species. Carrying out this experiment in the field also allows me to get at vital rates other than growth/biomass accumulation such as seedling germination/establishment and survival, which will give a more complete picture of the effects of plant-soil feedbacks on plant populations.

PPE: Are there applications for your work in western rangelands?

AC: I wouldn’t say that there are specific and direct applications of this research to rangeland management, but our results do highlight that even in dryland ecosystems, soil microbes can play an important role in regulating aboveground plant dynamics. Another line of research in our lab that I am involved in examines the effects of biological soil crust communities, which are unique to drylands worldwide, on plant and arthropod community structure. Some early results from this work indicate that surface disturbance to biological soil crust communities could have cascading effects on aboveground community structure. Therefore, a comprehensive management and conservation strategy should consider not only the physical and chemical properties of the soil, but also its micro/biological properties.

PPE: You’ve received PPE travel awards to attend ESA conferences in the past. What advice would you give to new graduate students attending a large conference for the first time?

AC: I was introduced to the PPE section while attending ESA for the first time as an undergraduate student, and I do think that it’s been a wonderful way to have a ‘home base’ in the Society and a way to meet a smaller subset of people across all career stages. As a new graduate student, I think it’s helpful to remember that you have just as much a right to participate and make your voice heard (if you choose to) as any senior member of ESA. People are nice and enjoy compliments and questions about their science, so don’t stress out about whether your comment is insightful or good enough before you say something. If there is someone specific you want to connect with, try emailing them before the conference to set up a meeting, or inviting them to your poster/talk. Also, apply for section/chapter travel awards! There are so many and they are generally under-subscribed and require minimal work. Not only is the funding a bonus, but you then get to meet and interact with people who are in your subdiscipline at the mixers/business meetings which can be interesting and fun.

PPE: You are part of a lab that moved to a new university during your Ph.D. work. What do you think grad students facing a similar move can do to make a transition like that positive?

AC: Moving is always hard, and that stress can come from all aspects of being a grad student be it social, academic, familial obligations, etc. For me, the biggest stress at the time was losing my new network of friends just as I was beginning to feel that I was fitting in. One great piece of advice I received when I moved as a second year PhD student was from a previous mentor who had made a similar transition in her own PhD life. She told me to just think about it as an opportunity to have twice as many friends to catch up with at future conferences, and I’ve been incredibly lucky that it is exactly the way everything has turned out (thanks, Laura!) I think keeping an open mind and being flexible about study systems and questions also helps, particularly if you move earlier on in your grad career. My move to New Mexico meant that all of a sudden I had access to this desert grassland ecosystem, which, while different from the winter annuals and cool season grasses I started my PhD work on, proved to be an amazing study system. Also, seek out mentors who are invested in your (and your advisor’s) success at the new institution. My new committee were (and still are) super supportive in accommodating course credits and requirements from my previous institution, which made the transition so much less painful. Finally though, it does pay to be realistic. Know that once you move, you will have to spend the first semester figuring out different degree requirements, transferring grants, helping set up a new lab, starting new research projects, meeting new people, and it will slow your science down. But for me at least, I can definitely say that four years down the line, this experience has turned out to be a net positive!

Read more about Anny’s research at her website.

Highlighted Young PPE Member of the Month – September 2016

Robert K. Shriver

Bob Shriver is a Ph.D. candidate at Duke University in the lab of Dr. William F. Morris. He received in B.S. from the University of Wyoming, and is now studying climate effects on plant demography. His work has been supported by several fellowships, including a NSF Graduate Research Fellowship.

PPE: Your research examines the effects of variability in climate on plant populations. Can you tell us why that’s an important and timely topic?

RKS: So, Long-term averages provide some of the clearest indicators of the magnitude and direction that climate is changing, but from the perspective of plants I think they can be somewhat irrelevant. Plants have to deal with changing environments day-to-day, week-to-week, month-to-month, etc., and these changes can be quite extreme. I think understanding how plants respond and cope with this variability, demographically, will really be key to understanding how populations respond to climate change. Climate change is expected to make weather in many ecosystems more variable and extreme. Population ecologists have a long history of looking at variability per se, but I think we are really just beginning to understand how plant demographic rates and populations respond to their own dynamic environments.

PPE: What have you found so far, and how do you want it to influence other plant ecologists?

RKS: I think one of the more important results of my work with desert annuals is realizing just how important environmental variability that we often ignore can be. And, not just that the variability exists, but the actual conditions themselves – thinking more in terms of a time series of environmental conditions rather than just a mean and variance.

Annual censuses that many demographers use (including me) are nice, logistically, but summarizing the environmental conditions over a year may not mean much to a plant. I think we can miss a lot of what controls population and community processes – growth, survival, resource partitioning – by not explicitly acknowledging this variability. It can become a bit of fishing expedition to find what factors best explain performance, but I think basic physiological processes are a good place to start and work out from.

PPE: How do you hope to continue this research in the future? What do you see as the next big step?

RKS: Sort of continuing from the last question, I see a lot of exciting work possible at the interface of ecophysiology, life history, and demography. I think life history tradeoffs are really fascinating but there has not been much work actually investigating the functional basis of these tradeoffs. Why, for example, does faster growth usually come at the cost of lower survival? I think understanding the link between physiological processes and demographic patterns could go a long way to helping predict how species will respond to climate change.

PPE: Thinking back about your experiences in grad school, what advice would you give to students just starting their graduate careers?

RKS: Everyone has different experiences and feelings about grad school, but what really gets me excited about ecology is getting outside and spending time in places I love. I think I would tell them to spend as much time as you can in the field, learn about your system, and let it show you what is interesting.

Also, one of the biggest perks of grad school is the freedom. Enjoy it! Explore lots of different skills and interests both scientific and not.

For more information on Bob’s research and his publications, check out his website: http://rkshriver.weebly.com/cv.html

Highlighted Young PPE Member of the Month

Martina Treurnicht

A recent paper by Martina Treurnicht et al. in Journal of Ecology focuses on variation in key demographic rates at large spatial scales, providing a demographic basis for understanding the relative role of environmental drivers in plant population dynamics. A comprehensive analysis of over 3000 shrub populations sampled across the geographical ranges of 26 shrub species with fire-dependent life cycles allowed the authors to determine how biotic (population density) and abiotic factors (climate, fire and soil nutrients) shape the large-scale dynamics of these shrubs (Proteaceae). This spatially explicit demographic study quantifies the contribution from different ‘environmental drivers’ over the life cycle of the study species and shows how climate and fire interchangeably play a role in their population dynamics. In addition to environmental and disturbance factors, density dependence of demographic rates were also considered. Demographic responses to environmental drivers reveal both consistent and differentiated responses among species. The research contributes directly to a demographic research agenda for biogeography, provides vital clues to understand relationships between demography and range dynamics and provides novel insights on the combined effects of environmental factors under global change.

More on Martina’s research:

Martina is interested in ‘real-world ecology’; how large-scale demographic variation and functional traits shape the population dynamics and ecological niches of plants. Martina also has a deep interest in conservation ecology; understanding and documenting threatened plant diversity in biodiversity hotspots where she strives to connect academic research with applied conservation. She is currently finalising her PhD dissertation at Stellenbosch University (South Africa) and aims to ground her research both locally and internationally. So far, her PhD journey has been an interesting one; which provided opportunities to work both locally and internationally (in Germany and France). More information on Martina’s working groups, ongoing research and study supervisors can be found in the links below:

https://ecology.uni-hohenheim.de/

http://www.sun.ac.za/english/faculty/agri/conservation-ecology

http://www.isem.univ-montp2.fr/

https://fynbosser.wordpress.com/

Highlighted Young PPE Member of the Month

Dr. Roberto Salguero-Gomez

An international researcher who is making strides in the field of comparative demography

By Nana Zhang, ESA Plant Population Ecology (PPE) section, and Roberto Salguero-Gomez 1/22/2015

While big data has become a very relevant topic in ecology and evolution, scientific research also faces the challenge of better integrating observational and experimental data to address timely questions. With this motivation in mind, the newly published paper on a revolutionary database of plant matrix population models, the COMPADRE Plant Matrix Database (Journal of Ecology, 2015,103: 202-218), opens a long desired door towards the big data era for plant demographic research. COMPADRE (www.compadre-db.org) is an unprecedented, open-access database that includes high-resolution demographic, taxonomic, ecological, biogeographic and phylogenetic information for hundreds of plant species around the world. The leading author, Roberto Salguero-Gómez, has been chosen as the February 2015 highlighted member by our PPE section!

I was very impressed by Roberto’s CV when I first saw it. He enjoys combining computational research with fieldwork around the world (his sites include Spain, England, Germany and Australia), while keeping rather productive. When I talked with him, I realized what an international researcher Roberto is! Roberto obtained his bachelor’s degree in Spain (where he is from), and then furthered his education in the UK and Austria before moving to the US, where he received his PhD from the University of Pennsylvania in 2011. After that, he has been a postdoc in Germany and Australia. Right now, he holds simultaneous academic appointments with the Australian Research Council, where he is a DECRA fellow, the Max Planck Institute (Germany), and Trinity College Dublin (Ireland).. He said, “Moving around has radically changed the way in which I think about ecology.” He thinks of his job as one of his hobbies. Indeed, he keeps busy while having lots of fun.

When asked why he became interested in ecology, Roberto told an unexpected story. He said he was going through a difficult transition from high school to college in his freshman year, and his botany course did not go well. “My mom gave me a consolation prize when I failed my first botany midterm: a cactus. I was so fascinated with its form that I started collecting succulent and desert plants, and next thing I knew I had over 200 species around our house. It was at that time that I realized how abundant life is, and that I wanted to do independent research in biology”. He continued reading about desert ecology, and eventually decided to pursue a PhD in ecology.

Roberto has been very successful in garnering grant funding to support his research. He leads a group of 11 BSc and MSc students at the Max Planck who carry out the acquisition, digitalization and error-checking of data for COMPADRE, and supervises two PhD students. He said the “decent” productivitvity at work comes from his enthusiasm. “My friends view me as a bit of a ‘hyper-active’ person. They say I’m rather energetic.” About the secret of being energetic, he said, “of course I drink a lot ofcoffee, but I am truly inspired to do my work.”

His time management skills have improved during the training process, as “transitioning from one task to another is getting faster.” Meanwhile, he also emphasized the importance of getting involved. “You also need to get involved with mentoring, departmental and other activities.” Roberto has been the founding member of both the International Network of Next-Generation Ecologists (INNGE) and the Early Career Section of the ESA. He was the ESA Student Section chair (2008-2010) and the ESA PPE Section student liaison (2009-2010) and secretary (2010-2012). Furthermore, periodically, he writes a popular science blog about his research to update his family and friends (See “Memories” on his website).

As an international student at UPenn, Roberto had to face an importance hindrance in applying for research grants: he was not eligible for major national funding due to his foreign status. Yet, he managed to use this to his academic advantage. “True, I wasn’t able to apply for major NSF funding, but I compensated by TAing more classes to obtain supplementary funds for my research.” Additionally, He advises students to, “…focus on smaller grants if big ones are not applicable… It is indeed critical to start as early as possible”. Currently he has received over $1 million in grants and fellowships from 15 different funding sources and five countries. He said, “The most important point is not focusing on one a single discipline. All the ideas and tools I learned over the years ended up helping me do a lot of different things, from biomolecular characterisations of oxidative stress to comparative biology. This approach requires constant movement among different fields”. An open mind, with a never-stop-learning heart, is the key to success.

Two of Roberto’s research interests are comparative biology and demography. The COMPADRE database is a huge leap forward in the field of comparative population ecology “I feel that ecology should put more attention on replication through space and time… how else are we going to know if an isolated observation really leads to a rule or to an exception?” Instead of finishing a PhD project over 4-5 years with one population, “we need longer intervals and to conduct experiments across greater spatial extents”. “Some theories have been developed with very limited data,” however, COMPADRE provides a platform to “re-test and re-evaluate these theories. In addition to the newly released COMPADRE database, Roberto is also the leader of the COMADRE animal matrix database (www.comadre-db.org), which includes data from over 1,300 animal species (soon to become open access online).

Right now Roberto is finishing some papers where he is examining the role of life history trade-offs in the evolution of senescence in plants and animals. Roberto’s plans for 2015 include finishing some papers where he is examining the role of life history trade-offs in the evolution of senescence in plants and animals. Also, he will be running a workshop at the ESA 2015 conference on comparative demography and phylogenetic analyses using COMPADRE. Roberto and his collaborators are currently developing two R libraries to interact with COMPADRE and facilitate comparative demographic analyses.

Roberto is currently looking for jobs in the USA and Europe; more on his research can be found here.

Nana Zhang is a PhD candidate at the University of Pittsburgh, and she thanks for the help of Lynn Adler, Aldo Compagnoni and Janette Steets for polishing this interview.

Highlighted Young PPE Member of the Month

Dr. Eugenio Larios Cárdenas

“I loved the desert, and I am amazed by its diversity.”

By Nana Zhang, ESA Plant Population Ecology (PPE) section 12/19/2014

When thinking about the desert, the first impression to me involves sandy, arid, and endless space, but for Eugenio, it means vibrant, exciting, and fun to work with. Being amazed by the diverse life in the desert, Eugenio devoted himself to desert ecology on the border of Mexico and the United States. In December 2014, he was selected as the highlighted young scientist of the month by our PPE section!

Deserts cover about 20% of the land on earth. It takes special adaptation for species to survive in deserts. However, the study of desert ecology is not an easy task. Very little is known about the adaptive mechanisms of various selective forces in the desert. As a PhD student at the University of Arizona until May 2014, Eugenio worked with the desert annual plant species, Dithyrea californica/ Harvey (Brassicaceae), as a model to answer questions related to natural selection in deserts. Dithyrea californica, commonly called spectacle pod, is a widely distributed winter annual plant species residing in desert habitats.

In their newly published paper in Ecology, (95(11), 2014, pp. 3213–3220), Eugenio and his colleagues from Universidad Nacional Autonoma Mexico, Instituto de Ecologıa, Hermosillo, Sonora, Mexico and from the University of Arizona presented the first empirical evidence that larger seeds have higher fitness through the life cycle. This study emphasized the lifetime effects of natural selection on seed size, especially persisting benefits until adulthood. This study highlighted the adaptive significance of larger seed size in the desert environment. In his highlighted paper, Eugenio combined data from Sierra del Rosario, Sierra Blanca in Sonora, Mexico and Coahella Valley Preserve in California, USA.

After completing his bachelor’s degree in ecology, Eugenio worked in various positions in the ecology field before pursuing a PhD. His experience with an ecological monitoring program in the field was especially inspiring for his career. He said, “The natural reserve experience was the main reason for me to pursue a PhD”. When asked why he is interested in desert ecology, he mentioned that during the field work, he was “amazed by the diversity” of the plant species in the desert. During his PhD studies, Eugenio spent most of his time in the Sonoran desert on the border of Mexico and Arizona, and he was extremely excited about working there.

Eugenio studied in Dr. Lawrence Venable’s lab, and he highly valued his PhD training. He mentioned that, “PhD training taught me to make sacrifices, and made me a better person.” Obtaining a PhD is not just an enjoyable training for science, but also a necessary training for us to figure out our lifetime enthusiasm. You learn about the most important things for you to achieve, and for Eugenio, that is to study the diversity in the desert. He is very proud of being an ecologist. “ I am a scientist now, that feels so good.” He said he felt “very lucky to have Dr. Venable as his PhD advisor…I really liked that he reserved Fridays for his students only. He is a good friend. He is very knowledgeable…”.

His advisor, Dr. Venable, praised him as “a desert rat”. He said, “…My first thought was – this guy knows everything about the amazing Pinacate region and has all the connections and logistics to go anywhere and do great desert ecology in places few people could! That first impression proved true. He conducted an excellent project bringing together good science and a spectacular field system in a place few grad students could pull it off…”. The excitement for the desert is exactly what amazes us about Eugenio!

The biggest challenge for Eugenio to get a PhD was his long disconnection with academia. “I had been out of academia for a long time,” so his unfamiliarity with science, combined with the language and cultural shock, was very tough for Eugenio in his first three years of graduate school. Luckily, his PhD work was supported by the Mexican government, which comes with the condition of going back to serve his country for one to three years after completing his program. But he said, “I wanted to come back anyway, I feel like I could accomplish a lot here.” Meanwhile, the government scholarship has been “….very helpful. I can focus on science…”. This support was no doubt helpful and well-deserved during his hard work over the years.

When we interviewed him, Eugenio was still finishing up two other projects in collaboration with the National Park Services. He is starting his new career as a postdoctoral fellow at the Instituto de Ecología, UNAM in Hermosillo, Sonora, México this coming January. His area of interest would still be on desert ecology at the border of Mexico and the US.

Eugenio has been an ESA PPE member since 2009, and we feel lucky to have him as a colleague. We wish him all the best for a successful career as a desert ecologist, and we look forward to reading more about his work.

PS: At the end of the interview, when I asked Eugenio how he felt about being elected as the highlighted young scientist of the month from our section, he said “I feel like all the hard work over the years has been valued and that it has really paid off.” This is exactly the motivation for us to have the monthly selection and to recently start conducting interviews on the highlighted members. We would love to encourage and recognize all the hard work for many young scientists along their way to success.

Nana Zhang is a PhD candidate at the University of Pittsburgh, and she thanks for the help of Lynn Adler, Aldo Compagnoni and Janette Steets for polishing this interview.

Highlighted Young PPE Member of the Month

Dr. Gerardo Arceo Gomez

“Publishing papers is not the only goal, learning skills is also the goal”

— Interview of Dr. Gerardo Arceo-Gomez

By Nana Zhang, ESA Plant Population Ecology (PPE) section 11/25/14

While most people are amazed by the beauty and variation of nature in plant communities, Gerardo pushed to understand the evolutionary processes and consequences underlying plant diversity.

In their newly published paper in American Naturalist (183(2): E50-E63), Gerardo and his PhD advisor, Dr. Tia-Lynn Ashman, at the University of Pittsburgh, showed that the diversity of co-flowering plant communities could affect female fitness and further influences the flower longevity in Mimulus guttatus, also known as monkey-flower,a very popular wildflower seen along the banks of creeks and rivers in North America. Thus this paper demonstrated the importance of community complexity in shaping the evolutionary processes.

Gerardo received his PhD in March 2014, from the University of Pittsburgh, finished his postdoc training at Cornell University and has just returned to his home University in Mexico, the University of Yucatan, for further postdoc training. It is my honor to interview him as the highlighted member of the month and get to know him more as a colleague.

Gerardo has a natural interest on nature, outdoor and plants since he was a kid, but his pathway to become a plant ecologist was not direct. He first studied biology in college, and became interested in plant-animal interactions while in Dr. Victor Parra-Tabla’s lab. “He is the person who showed me how cool science could be”, Gerardo said. After college, Gerardo worked on environmental impact studies in industry for about one year. He noted that “working on that particular area let me realize that my main interest is still in science”. With this motivation, he pursued a Master’s degree in Mexico and then got his PhD degree at the University of Pittsburgh in the United States.

When asked why he chose Dr. Tia-Lynn Ashman’s lab for his PhD work, he said Dr. Ashman was the main reason he came to Pittsburgh. “I was just looking for the right person to work with. She is productive, successful and above all a great scientist. I learned much more beyond my expectations”. He was certainly right! Gerardo already has ten publications, with seven first-authored and three co-authored papers in highly ranked ecological journals.

However, in Gerardo’s mind, “publishing papers is not the only goal for me, acquiring good scientific skills is also the goal”. In graduate school, asking interesting questions and learning different tools to answer those questions were the most important things for Gerardo. As he stated, I“…learn as much as I can. Do it well.That is the key for me — to ask questions and have the tools to answer themin the future”. “But publications come along…”, and that is so true.

The most valuable aspect about research for Gerardo is that “small research questions can always reveal unknown patterns”. And it is the excitement to unravel novelty from elaborate design that motivates him to push the barrier of knowledge all the time. Right now Gerardo is mainly focusing on two projects derived from his thesis. One project is investigating hetero-specific pollen transfer, and its evolutionary consequences. The second project looks at the functional diversity of the plant communities and its importance to reproductive successes. Both projects will contribute significantly to our understanding of plant-insect interactions.

Besides research, Gerardo has broad interests in life. He likes reading non-scientific books, going to concerts, photography and watching movies.

Gerardo has come a long way from his childhood interest to become a productive researcher. He will continue to ask interesting questions and use the tools he learned from graduate school to solve them. In the future, Gerardo sees himself as an independent researcher with his own research lab, contributing to the growing ecology research in Mexico. As he kept saying during the interview “I am happy with the work”. Indeed, his sincere enthusiasm is evident just by talking with him.

More on Gerardo’s research can be found here.

Nana Zhang is a PhD candidate at the University of Pittsburgh, and she thanks for the help of Lynn Adler, Aldo Compagnoni and Janette Steets for polishing this interview.

Highlighted Young PPE Member of the Month

Dr. Billie Gould

Goul, B, DA Moeller, VM Eckhart, P Tiffin, E Fabio, and MA Geber. 2014. Localadaptation and range boundary formation in response to complex environmental gradients across the geographical range of Clarkia xantiana ssp. Xantiana. Journal of Ecology 102:95-107.

A long standing challenge in plant ecology and evolution is identifying the forces limiting species geographic distributions. For some species, geographic ranges are clearly limited by physical dispersal barriers, but in the absence of barriers adaptation may be limited by lack of adaptive trait variation. In this study we examined patterns of differentiation across the majority of the geographic range of a California endemic wildflowr, Clarkia xantiana ssp. xantiana. We found that edge populations are well differentiated from central ones, and despite evidence of locally adaptive selection, heritable variation is not reduced in edge populations. These results challenge the idea that lack of adaptation at species range edges is driven largely by patterns of selection and gene flow across a heterogeneous landscape.

A link to the paper and more about Billie’s work can be found here.

Highlighted Young PPE Member of the Month

Dr. Scott McArt

McArt SH, Halitschke R, Salminen J-P, and Thaler JS. 2013. Leaf herbivory increases plant fitness via induced resistance to seed predators. Ecology 94(4):966-975.

Leaf herbivory can induce defenses in plant reproductive tissues, yet little is known regarding the fitness consequences of leaf-to-reproductive tissue induction in nature. In this study, we show how leaf herbivory from an invasive beetle induces an accumulation of complex phenolics in reproductive tissues of a native plant. Consequently, seed predation by three native Lepidoptera is dramatically reduced, while leaf herbivory itself has little impact on lifetime reproductive output. Our results show that a native plant benefits from being consumed by an invasive folivore, and that leaf-to-reproductive tissue induction of chemical defenses can be an adaptive trait in plants.

The paper and others by Scott can be found here.