My scholarly interests broadly encompass applied and theoretical questions related to diversity and change in plant communities. In research foci, I try to link my research to management. My work also often explores plant-insect interactions, especially insect herbivores and pollinators. My approaches combine field work with common garden and greenhouse experiments, and the tools of molecular biology because integrating observational and manipulative research has more power than pursuing one approach alone. I have built a research program that includes undergraduates and researchers at other institutions. Over time, I have investigated these four areas of interest:
1) How do abiotic and biotic factors shape diversity within and among plant populations?
My Ph.D. research demonstrated that plant life-history traits varied dramatically in a grassland community where populations were less than 1 km apart. Over time, some populations fluctuated wildly while others were resilient to change; initially our lab thought these demographic trends were explained solely by patterns in presence or absence of herbivorous insects and their predators. However, I demonstrated that genetic differentiation existed among the populations and interacted with abiotic trends as well as patterns of pollination and herbivory. We found that plant alkaloid composition and quality affected insects in unique ways, influencing feeding patterns and subsequent insect community composition. My work contributed to a better understanding of the evolution of local adaptation, and how demographic and physiological variation is both influenced by and influences community processes.
I continue to be intrigued with how multiple interactions affect plant populations. Recently I have started greenhouse experiments aimed at quantifying the degree of differentiation in morphological and reproductive traits among populations of Lomatium macrocarpum and the rare Arabis fecunda. The questions I plan to address are two-fold: 1) are life history traits genetically determined and/or environmentally influenced? 2) If environment influences the life history, what environmental factors can ‘switch on’ the different strategies (e.g. nutrient and water resources)?
2) Invasive Species Ecology
With John Maron and Marilyn Marler, I investigated how community diversity and resource availability influenced invader impact and ecophysiology of natives in western Montana. Experimental assemblages that varied in native plant species and functional richness were constructed. Assemblages were ‘invaded’ with spotted knapweed (Centaurea maculosa), dalmatian toadflax (Linaria dalmatica) and sulfer cinquefoil (Potentilla recta), three widespread invasive plants in the intermountain west. Plots received ambient or supplemental water. We compared how plant physiological traits (water use efficiency, N:C content and leaf construction) were impacted by diversity, resource availability and invader identity. Rarely have underlying physiological traits been examined in broader ecological contexts; these traits are important since they may be the mechanisms that underpin resiliency or adaptation of communities. I will continue to investigate the physiological mechanisms underlying variability in plant interactions.
My research students and I have investigated how exotic species such as sweet clover invades (primarily via disturbance) and how it can be partly controlled by shifting soil nutrient levels. My Master’s research focused on how community attributes influenced the spread of an introduced cordgrass in Pacific salt marshes. Our research helped land managers better assess the impact of this invader in west coast salt marsh mitigation and restoration projects, and provided important information to the US Fish and Wildlife Service as well as researchers in Spain. I will continue to investigate questions related to invasive plants and ways they affect native competitors as well as the determining best management practices.
3) Effects of Habitat Fragmentation
Students in my lab are keenly interested in plant diversity of fragmented ecosystems such as prairies and oak woodlands. Less than 1% of tallgrass prairie and oak woodland exist and most are isolated islands in a sea of agriculture and development. We have characterized demography and genetic diversity of species important to these communities and how fragmentation may affect the gene pool of species such as Quercus macrocarpa (bur oak) and Lithospermum canescens (hoary puccoon). Fragmentation over time has increased homogeneity within areas, which has the potential to limit responses to change over time. In another project, students assessed the efficacy of two prairie restoration projects by measuring ant diversity and abundance; they found that the most diverse ant communities were associated with high vegetative diversity, less disturbance and more stable ecosystem processes. My lab also has established monitoring plots at several restoration prairies with different environmental characteristics, but similar species compositions, as a way to examine how abiotic factors may influence community composition long term. By comparing diversity among populations, our work contributes to a more thorough understanding of how plants respond ecologically and evolutionarily to isolated, fragmented landscapes. On a practical level our research has allowed land planners (TNC, DNR) to better understand the level of diversity (genetic and morphological) and to evaluate methods of restoring or enhancing these habitats. As habitats become more disturbed interest in restoration and adaptive management has grown, however, few researchers empirically document best practices for community restoration and management.
4) Climate and Communities.
Peter Lesica and I analyzed long-term vegetative transects to examine how the phenology of Montana’s intermontane grassland species have changed with climate, especially with changes in temperature and precipitation. Our study showed that changes in precipitation are as important as temperature for advancing flowering phonologies in Montana. Phenological changes have the potential to disrupt plant-animal interactions and may cascade affecting other community members. Moreover, alterations in precipitation patterns are likely to have large ramifications for other plant community processes in south and western Montana. I continue to be intrigued by questions related to climate and its potential effect on communities. I also think that use of recent paleoecological records may help us better understand how climate and community processes interact.
My scholarly process
“The more you look, the more you see.”
I enjoy exploring the theories that ecological and evolutionary research produce. I generally have a couple of projects that are simmering in various stages of completion. Sometimes new ideas are percolating while I consider experimental design or the analysis of another. Extended blocks of time to think through ideas, write or analyze seem to be the primary limiting factor in completing more projects. I will continue deepening my experiences as a researcher and explaining patterns in the natural world.
I enjoy doing research with collaborators at research institutions because I can more quickly accomplish the outcomes of my scholarly goals. However, my research program at Gustavus gives students the opportunity to conduct their own research and to think critically about issues. Since I allow students to develop their own unique projects rather than dictating a path that is only congruent with my research agenda, it means their research requires close and frequent interaction with me.
My research lab is another form of mentoring and teaching. I encourage students to explore options, pursue external research opportunities, write grants, read widely and deeply, build connections among ideas and find their niche. I expect students in my lab to work hard, take calculated risks, keep excellent records, teach one another and be creative. In addition to providing a valuable service for The Nature Conservancy and Minnesota State Parks, my students have made important multi-agency connections that have led to career opportunities. I enjoy celebrating their accomplishments even if it does not include research in their future. I highly respect the work that these students have produced over the years as well as how they grown intellectually and personally as a result of our collaborative research experiences.
I believe that it is not enough to simply be engaged in professional activities, but one must show evidence of completion. Completion is a full circle of scholarship that includes publications in peer reviewed journals and presentations at scholarly meetings, where experimental questions, results and conclusions can be scrutinized, critiqued and shared in an open forum. Only when research goes public can it be included into the scientific canon.
One of my graduate school mentors suggested that success at many universities in the 1980s was defined by publishing one peer reviewed paper per year. While the bar has increased substantially at research institutions, there are many at liberal arts colleges that say that this remains a respectable goal. I have managed to publish, on average, one time per year, despite heavy teaching, advising and committee expectations. Moreover, I have published a peer reviewed paper with every student that has collaborated with me for longer than 3 months (n= 12 students). This has not been easy. For every publication we have in print, it took at least one year of data collection, and at least another year of analysis and writing, but generally it means more than two years of work. There are loads of other experimental data that were generated, but were never discussed in the publication; for every successful approach there is at least another one that was worked on as long, but did not work out (negative results, recalcitrant organisms or natural disasters in lab, greenhouse or field). Delays also are inevitable because of the peer review and revision cycle can extend 3-9 months for each submission or resubmission. Despite these impediments we have produced final products of quality. For articles that I publish with university collaborators the research is accepted top peer-reviewed journals (Ecology, Evolution, AJB, Oecologia). The undergraduate research also has been judged by peers and editors to be worthy of publication in other good journals. We have worked hard, produced good research and found appropriate ways to disseminate results. We have been persistent through the whole process despite the roadbumps and the protracted time between when the work is done and when article actually reaches press.
I have given presentations or displayed posters at many scholarly meetings or conferences on own or with students. I try to take my research students to a national meeting such as Ecological Society of America (ESA) because it broadens their understanding of science and how they can contribute to the academy. It also gives them an opportunity to talk about and promote their good work. I also have been invited to give seminars at other institutions such as the University of Nebraska Lincoln, Colorado State University Pueblo and Doñana Biological Station in Spain.
I also try to make ecology research understandable to the general public. On my sabbatical I gave informal talks about plant-mycorrhizae interactions and invasive species ecology for the City of Missoula Public Lecture Program. The program drew in about 30 individuals interested in hearing more about the ecology and control of invaders such as knapweed, leafy spurge and toadflax. At Gustavus, I gave a talk at the City of St. Peter’s continuing education program discussing invasive species. I also try to give Shoptalks about my research so I can share results with my Gustavus colleagues and I will continue to disseminate my research findings in these different contexts.
A critical part of my work as a scientist is to find funding. I apply for grants for myself as well as for collaborative work with students or other faculty. I regularly apply to in-house sources of funding (Research Scholarship and Creativity Grants, Faculty-student Collaboration grants, Lily, Rockefeller, etc) and external grants or fellowships (NSF or Kenan Fellowship). All the research grants that I have received have resulted in a publication and/or presentations. Writing grants takes an enormous amount of time and federal grants are extremely competitive for colleagues at research institutions let alone liberal arts colleges (<19% success rate in all of life sciences and <2% of NSF’s budget goes toward non-medical life science). As such I have chosen to spend time developing research programs that require less funding; people power is the limiting factor in most of the experiments I conduct. I believe in paying my research assistants a fair wage and try to shift any funding I get for research to student stipends. I will continue to find ways to support students.