Principal Investigator - Janneke Hille Ris Lambers
Janneke Hille Ris Lambers
I received my Ph.D. from Duke University in 2001 (working with James S. Clark). While at Duke, my field work took me to the Coweeta Hydrologic Laboratory in western North Carolina (an LTER site), where I studied differences among temperate tree species in seed dispersal, seed banking and density-dependent mortality, and how those differences contribute to diversity-maintenance.  I then worked with David Tilman at the Cedar Creek Ecosystem Science Reserve (another LTER site associated with University of Minnesota). There, I studied how declining diversity and species identity influences productivity and the impacts of global change on seed production. In a subsequent postdoc at University of California, Santa Barbara (working with Jonathan Levine), I focused on the factors that allowed Mediterranean annual grasses to dominate over the diverse California annual grasses and forbs as well as the contributions of niche and neutral processes to the coexistence of Serpentine annuals.  I arrived at University of Washington in 2006.

I am a plant community ecologist broadly interested in: 1) the maintenance of species diversity and 2) how global change (climate change, invasive species, nitrogen deposition, etc) alters the structure and function of plant communities.  I approach questions of interest with observational studies, manipulative experiments, and statistical modeling, working in a variety of habitats (North Carolina, Minnesota, California, Washington). Check out the Research page on this website for more information.

Download CV as a pdf file

Postdoctoral Research Associate - Cynthia Chang (Assistant Professor at UW Bothell Fall 2014)

Cynthia ChangI am interested in plant community assembly following a disturbance because it gives us unique insight into the dynamic nature of ecosystems through time. I am studying primary succession processes on Mount St. Helens using a 30-year dataset (Roger del Moral) since the volcanic eruption in 1980, to understand how plant trait distribution and species composition change over the course of succession. In plant communities, dispersal strategy, life history, and growth traits are deterministic factors that influence community interactions. Stochastic factors, such as random chance, can also dictate how communities assemble. Both types of these interactions influence plant succession.

The research questions that this project will address are:

1) What is the trait distribution of the plant community over the course of succession?

2) What is the relationship between temporal patterns in species abundance to trait changes over time?

3) Can we use this trait and species abundance information to determine the importance of deterministic vs. stochastic factors for primary succession?

To answer these questions, I use a combination of literature, field, and greenhouse data to create statistical and simulation models. Specifically, I use Bayesian hierarchical modeling techniques to build statistical models to examine observed field patterns. In addition, I (together with Jeremy Lichstein, University of Florida) am building an individual-based stochastic simulation model to understand how differences in species composition and trait distribution may be explained by stochastic (eg. priority effects) and deterministic processes (eg. competition for limiting resources). 

Using theoretical tools to link pattern to process will allow us to build upon our understanding of how communities assemble and also allow us to predict how ecological communities will respond to large-scale disturbance events.


Postdoctoral Research Associate - Melanie Harsch

Melanie HarschI am interested in plant species response to climatic change. In particular, I study 1) the processes driving range dynamics and 2) how patterns, in particular, deviations from the norm, can provide new insights. Rather than considering variability to be noise, I consider variability to reflect previously unidentified or overlooked factors. My goal is to use deviations in expected patterns in plant species distribution and traits to understand and, more realistically, predict response to climatic change. To address this goal I use observation data, field experiments, and statistical modeling.

Currently I am using mathematical and statistical models to assess global variability of plant species response to climate change. To understand and predict climate change impacts on species range margins we need more sophisticated mathematical (for creating generalizations) and statistical (for creating predictions) models that take into account species sensitivity (functional traits) and ability to respond to climate change (demographic and dispersal rates) along with possible interactions with the rate of climate change.

The overall goals of this project are to: 1) use theoretical mathematical models, based on stage-structured integrodifference equations, to identify potential threshold limits of tolerance and relationships not readily identified through observational studies and 2) .use statistical models, built within a hierarchical Bayesian framework, to incorporate complexity apparent in natural systems, providing greater realism in analyses and accuracy in predictions.


Postdoctoral Research Associate - Steve Kroiss

Steve KroissIn the face of daunting climate change projections, we lack a clear understanding of the degree and speed with which individual species and whole communities will respond to climate change.  My research aims to address this issue by combining population and community ecology research in order to understand the drivers of range dynamics.  In particular, my main research questions are:

1) How do plant vital rates and population dynamics change across species ranges?
2) Do the effects of seed availability, abiotic factors, and biotic factors on plant population dynamics change across species ranges? 

 3) How will shifts in climate affect plant population dynamics across the species range?
4) Will species distributions keep pace with climate change?

To examine these questions, I am employing a diverse set of observational, experimental, and modeling approaches to study the range dynamics of six conifer species in Mt. Rainier National Park, WA, USA.  To examine how vital rates vary across species ranges, I am examining how seedling recruitment and survival varies as a function of range position, seed availability and climate.  I’m following up this project with a transplant experiment targeted at assessing the importance of climate vs. competition on seedling survival between the core and edge of species ranges.  Ultimately, I’m interested in combining this data with ongoing demographic and seed dispersal studies to project how these species are likely to respond to shifts in climate.


Graduate Student - Ian Breckheimer

Ian BreckheimerHow do gene flow and local adaptation interact to define niche boundaries and geographic ranges? Answering this question is critical if we want to successfully manage ecosystems under climate change.  The climate optima of many species are expected to shift north by 700km and up in elevation by 800m over the next century due to climate change, putting tremendous pressure on plants to adapt or migrate. Despite these challenges, some recent models predict that long-distance dispersal of pollen may allow some species to rapidly adapt in place to shifting climates.  These predictions depend strongly on assumptions about phenology, gene-flow and local adaptation that are poorly constrained by data.  I intend to use molecular tools, common-garden experiments, and experimental crosses to determine how gene flow and hybridization influences current and future distributions of Mimulus guttatus and Mimulus tilingii (monkey flower species with contrasting altitudinal distributions).  

Originally from North Carolina, I’m joining the lab in 2012 after completing a masters degree with the Landscape Ecology and Biogeography group at UNC Chapel Hill.

Download CV as a pdf file

Graduate Student - Leander D.L. Anderegg

Leander DL AndereggI am broadly interested in the ecological impacts of climate change, with a current focus on tree species range shifts. Given the rapidity of current and projected environmental changes, we have neither the time nor the resources to study every species that may require conservation action over the coming century. I seek to understand biogeographic patterns in the nature of range constraints so that we can predict what trees are likely to experience range shifts where, even in the absence of detailed demographic data. Where are tree ranges more likely to be biotically constrained vs. abiotically constrained? How do ecotypic variation and phenotypic plasticity influence range boundaries? How do range constraints scale from elevational ranges to latitudinal ranges? Building on my background in plant ecophysiology and ecohydrology, I strive to combine physiological, community ecological, and biogeographic techniques to answer these questions.

As a native of Colorado, I grew up camping, hunting and fishing in the mountains of the Southwest where I witnessed first hand the ecological impacts of anthropogenic climate change. I began my research career as an undergraduate at Stanford University, studying the causes and consequences of recent drought-induced trembling aspen tree mortality in the Colorado Rockies. The results of this research (aspen forests are becoming increasingly physiologically vulnerable to drought and high temperatures, making future die-offs likely) launched me into a broader exploration of how climate change will affect the major forests of the western US. I joined the lab in 2012.

Download CV as a pdf file

Graduate Student - Elli Jenkins Theobald      Elli Jenkins Theobald

As a community ecologist, I am intrigued by the natural world and perplexed by the impacts humans are having on it. Specifically, I am interested in the biological implications of climate change. As the climate has warmed, many plant species have shifted their ranges both pole-ward and up in elevation, and these shifts are not projected to cease. However, biotic interactions can also determine species range limits, making climate-induced shifts less likely. My research is focused on three questions related to this broad observation: 1) What role does pollination play in determining plant species distributions? 2) Could an interaction between elevation and phenology (both flowering phenology and insect activity) enhance or slow climate-induced range shifts? 3) By modeling changes in snow duration are we able to predict past and future flowering phenology and range limits?

Using a strong elevational and climate gradient on Mount Rainier I will try to answer these questions and assess a few of the many potential biological implications of a warmer world. 

I am a Washington State native thus I came home to join the Hille Ris Lambers lab in 2010. Before graduate school, I was an Oakland public school teacher, teaching middle school and high school science. I graduated in January of 2006 with a degree in Biology and Environmental Science from Colby College (in Maine).  As an undergrad I was involved in a number of research projects including surveying vegetation recovery on Mount Saint Helens, investigating the pollination regime of a Costa Rican weed, and studying habitat-specific behavior in Black Capped Chickadees.  As a part of the Hille Ris Lambers lab, I have the opportunity to build on both my research and teaching experiences, and I am thrilled to be here.


MeadoWatch Coordinator & Lab Manager - Anna Wilson      

Anna Wilson
As a Northwest native, I grew up hiking the trails surrounding Mt. Rainier. I joined the lab as a summer field intern in 2012 after graduating from UW with a bachelor's degree in ecology, evolution and conservation biology. Currently, I work jointly as coordinator of MeadoWatch (a citizen science program on wildflower phenology) and as lab manager for the Hille Ris Lambers lab. As MeadoWatch Coordinator, I am excited about connecting the public to climate change research. Through our citizen science program, we recruit volunteers to collect phenological data on the wildflower meadows of Mt. Rainier National Park. With this information we hope to understand how climate change is impacting plant species' distributions to plan for a warmer future. As lab manager, I help coordinate many of the labs research activities. Additionally, I am conducting an experiment to assess whether a tradeoff between frost tolerance and growth rates (i.e. competitive ability) influences the distribution of dominant conifers at Mt. Rainier National Park.  I'm also interested in restoration ecology, conservation biology and science communication.

Current Undergraduates

  Hannah Besso (Mt. Rainier Research Intern 2014)
  Emily Chan (Mt. Rainier Research Intern 2014)
  Drew Lyons (Mt. Rainier Research Intern 2014)
  Lane Felker (Research on
  James Lucas (2014 Mt. Rainier REU)
  Gregor Siegmund
(2014 Field Crew Leader, Mt. Rainier Research Intern 2013)
  Hannah Wiesner (Mt. Rainier Research Intern 2014)

Graduate Alumni

Kevin Ford (grad: 2008-2014).
While in the HilleRisLambers lab, Kevin worked on a number of projects, including the relevant scale of microclimate variability for subalpine vegetation distributions; the relationship between tree growth across range limits, and the relative importance of climate and edaphic conditions for range expansions of treeline and subalpine plants. Kevin is currently a post doctoral research associate at the US Forest Service Pacific Northwest Research Station (Olympia, WA).

Ailene Ettinger (grad: 2007-2013). While in the HilleRisLambers lab, Ailene studied the relative importance of climatic constraints and competitive interactions for the performance of six conifer trees at their altitudinal range limits within Mt. Rainier National Park, using dendroecological techniques and a manipulative transplant experiment to answer her questions. Ailene is currently a Putnam Fellow (a competitive post doctoral position) at the Arnold Arboretum of Harvard University (Cambridge, MA).  

Susan Waters (grad: 2007-2013). While in the HilleRisLambers lab, Susan studied the role of indirect, pollinator-mediated interactions between native and exotic plants in a rare and heavily invaded habitat - south Puget Sound Prairies. Susan is also the co-founder of the awesome Urban Pollination Project (a citizen science project documenting urban pollination services in Seattle). Susan is currently a PIP (Principles in Pedagogy) Fellow at the Bothell campus of University of Washington (Bothell, Wa).

Haldre Rogers (grad: 2006-2011). Haldre Rogers was co-located in the Tewksbury and HilleRisLambers labs while at the University of Washington. Haldre studied the impacts of complete bird loss on Guam on the dispersal of tree seeds (with the majority of species in Guams forests dispersed by birds) and the insect herbivory of tree seedlings (potentially controlled by bird predation). Haldre continues to work in this amazing system (see her project website), and is currently a Huxley Faculty Fellow at Rice University (Houston, TX).

Sylvia Yang (grad: 2006-2011). Sylvia was co-located in the Ruesink and HilleRisLambers labs while at the University of Washington. Sylvia worked on the ecosystem engineering abilities of eelgrass (Zostera marina), using observations, experimental manipulations, and modeling. Sylvia is currently a Marine Scientist at the Shannon Point Marine Center (Anacortes, WA), which is affiliated with Western Washington University (Bellingham).

Undergraduate Alumni
  Cherry Chen (Mt. Rainier Research Intern 2013, undergraduate researcher 2011-2013)
  June Landenburger (Mt. Rainier Research Intern, undergraduate researcher 2013-2014)
  Jacqui Levy (Mt. Rainier Research Intern 2014)
  Katy Olsen (
Mt. Rainier Research Intern 2014)
  Sam Reed (Mt. Rainier Research Intern 2013, postgrad researcher 2013-2014)
  Caitlin Budd (
Mt. Rainier Research Intern 2012)
  Kathleen Burns (summer REU: 2012)
  Liam Fitzgerald (
Mt. Rainier Research Intern 2012)
  Natasha Lozanoff (Mt. Rainier Research Intern 2012)
  Anna O'Brien (undergraduate researcher, lab manager: 2007-2011): currently a graduate student at UC Davis
  Sara Eshe (undergraduate researcher: 2010-2011)
  Melissa Winstanley (undergraduate researcher: 2009 - 2010)

  Irene Weber (undergraduate researcher: 2009 - 2010): currently a graduate student at Southern Illinois University
  Courtenay Ray (Mt. Rainier Research Intern 2011): currently a graduate student at UC Santa Cruz
  Jennifer Rickwalt (
Mt. Rainier Research Intern 2011)
  Mitch Piper (
Mt. Rainier Research Intern 2010, Crew Leader 2011-2012)
  Courtney Wenneborg (
Mt. Rainier Research Intern 2010)
 Jonathan Deschamps (undergraduate researcher, Mt. Rainier Research Intern 2007 - 2009)
  Gerald Lisi (
Mt. Rainier Research Intern 2008, 2009)
Alan Wright (Mt. Rainier Research Intern 2009)
  Rachel Konrady (
Mt. Rainier Research Intern 2009)
  Tony Krueger (
Mt. Rainier Research Intern 2009)
  Amado Fuentes (
Mt. Rainier Research Intern 2008) 

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Biology Department
University of Washington
Seattle WA, 98195-1800
jhrl@uw.edu, 206-543-7389