Margaret E.K. Evans

Margaret E.K. Evans

Associate Professor

The University of Arizona


I am a plant ecologist whose research falls at the intersection of the climate crisis and the biodiversity crisis. My toolbox strongly features demographic data and models, and sometimes novel statistical methods (e.g., the use of Bayesian statistics for ecological forecasting).

The climate crisis

These days, my research is mostly focused on the climate crisis - in terms of the relationship between forests and climate. I’ve been combining tree-ring and forest inventory data to quantify how trees are affected by climate variation and change and how forest ecosystems feedback on climate via their removal of CO₂ from the atmosphere. The climate-growth relationships encoded in tree rings are used to make projections of future tree growth—“ecological forecasts”. This includes collaboration with the US Forest Service and Navajo Forestry Department to develop networks of tree-ring data sourced in forest inventories and tools useful for forest management and carbon accounting, aimed at forest resilience and forest-based “natural climate solutions”. I’ve also been working on developing demography-based models to predict how species' geographic distributions will respond to changing climate (“demographic range modeling”).

The biodiversity crisis

In the past, my work focused on the biodiversity crisis - in terms of the origins, dynamics, and conservation of plant diversity. My training (and experience) was in plant population ecology, including rare plant conservation, population viability analysis, evolutionary ecology, and comparative biology.

I work across the divide between basic and applied science, between ecology and evolution, and between the MacArthur and Odum schools of ecology. I am an integrative thinker who is interested in seeing the discipline of ecology grow, become stronger, and be applied to solve the pressing problems of the 21st century in an inter- and trans-disciplinary manner. In addition to my research activities, I sincerely enjoy teaching and mentoring.

  • Forest ecology
  • Carbon Cycle science
  • Tree Rings
  • Plant demography
  • Ph.D. in Ecology and Evolutionary Biology, 2003

    The University of Arizona

  • B.A. in Biology, 1993

    Reed College









Assistant Professor, Dendrochronology
Laboratory of Tree-Ring Research, The University of Arizona
Sep 2018 – Present Tucson, Arizona
Assistant Research Professor
Laboratory of Tree-Ring Research & Department of Ecology and Evolutionary Biology, The University of Arizona
Sep 2013 – Sep 2018 Tucson, Arizona
Post-Doctoral Fellow
Muséum National d’Histoire Naturelle
Jun 2010 – Jun 2013 Paris, France
Project EVORANGE: How does EVOlution affect extinction and species RANGE dynamics in the context of global change? Implications for ecological forecasting.
Research Scientist
Centre National de la Recherche Scientifique, Laboratoire Ecologie & Evolution UMR 7625
Sep 2008 – Nov 2009 Ecole Normale Supérieure, Paris, France
Post-Doctoral Fellow
Department of Ecology and Evolutionary Biology, Yale University
Aug 2007 – Sep 2008 New Haven, Connecticut
Post-Doctoral Fellow
Ecole Normale Supérieure & Muséum National d’Histoire Naturelle
Aug 2006 – Jul 2007 Paris, France
Post-Doctoral Fellow
Department of Ecology and Evolutionary Biology, Yale University
Sep 2005 – Jul 2006 New Haven, Connecticut
Research Associate
Archbold Biological Station
Sep 2004 – Sep 2005 Lake Placid, Florida
Analyzed demographic and weather data to identify climatic drivers of demography.
Visiting Scholar
Wesleyan University
Jan 2004 – Aug 2004 Middletown, Connecticut
Teaching Assistant
The University of Arizona
Aug 1998 – May 2003 Tucson, Arizona
Taught laboratory sections of Introductory Biology and Ecology. Assisted with Conservation Biology and Wildland Vegetation Management courses. Lectured on population viability analysis.
Field Assistant
Christensen Research Institute
Jan 1997 – Dec 1997 Madang, Papua New Guinea
Sorted collections of fig wasps and assisted George Weiblen in a pollination experiment. Participated in a collection trip in the Highlands to document the local flora.
Research Assistant
Archbold Biological Station
Sep 1994 – Jan 1997 Lake Placid, Florida
Observed pollinators and conducted controlled hand-pollination experiments to determine the mating systems of seven federally endangered plants endemic to the Lake Wales Ridge of south-central Florida. Supervised by Eric Menges (ABS) and Doria Gordon (The Nature Conservancy).
Biological Science Technician
U.S. Forest Service, Mt. Hood National Forest
Jan 1993 – Sep 1994 Gresham, Oregon
Sub-crew leader surveying for spotted owls.
Oregon Department of Agriculture & Native Plant Society of Oregon
Jun 1992 – Aug 1992 Oregon
Collected field data with Tom Kaye in his study of the demography and habitat characteristics of Cimicifuga elata, a rare plant.
The Nature Conservancy
Jun 1991 – Aug 1991 Portland, Oregon
Controlled exotics, monitored rare plants and communities, and helped maintain six preserves in Northeastern Oregon as Field Ecologist Berta Youtie’s intern.


Ecological Forecasting
This emerging approach in ecology emphasizes the need to predict the future state of ecosystems, natural capital, and ecosystem services, and, that while ecological systems are complex, there are strategies to improve the skill of ecological models, borrowed from numerical weather forecasting (iterative, near-term confrontation between model predictions and in-coming data) and using hierarchical Bayesian statistics (the ability to fuse different sources of data and characterize uncertainty).
Demographic Range Modeling
Climate has long been identified as the major determinant of species’ geographic distributions, and from climate-only (“climate-envelope”) models, it is estimated that ~15-35% of species are “committed to extinction” by climate change.
Tree-ring data sourced in a forest inventory context
Tree-ring time series data offer a lifelong, annually resolved record of a tree’s growth, making them a valuable source of information on aboveground woody biomass accumulation and hence carbon sequestration in forests.
Forest Management
Two lines of research in my group are aimed at creating useful tools for forest management in the face of changing climate. Courtney Giebink created a climate-sensitive empirical forestry (growth and yield) model using tree-ring data (Giebink et al.
Allometric Scaling
Population Modeling
Population Viability Analysis has been called the “flagship technology” of conservation biology (by Michael Soule). Kent Holsinger, Eric Menges, and I collaborated together for some years to develop a novel approach to population viability analysis (PVA): we built a hierarchical Bayesian (hB) model that draws upon data from all parts of the life cycle simultaneously to estimate vital rates and their covariation as a function of time-since-fire and random year effects.
Comparative Evolution
While a post-doctoral fellow at Yale University, I collaborated with Michael Donoghue and Stephen Smith to combine niche models and phylogenies to quantify climatic niche evolution and its role in the diversification of the “bird-cage” evening primroses (Evans et al.
Evolutionary Ecology
My training as a PhD student was firmly footed in the sort of MacArthurian ecology that focuses at the population and individual scale to ask questions about the selective forces that shape traits and life histories.
Conservation Ecology
My earliest work contributed to basic knowledge, either in terms of demography, reproductive biology, or genetic diversity, of the following rare plants: Asimina obovata (Annonaceae), Cimicifuga elata (Ranunculaceae), Dicerandra frutescens (pictured, photo by Reed Bowman) and D.
Example Project
An example of using the in-built project page.

Recent & Upcoming Talks

Recent Publications

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  • 520 621 1608
  • Bryant Bannister Tree-Ring Building 1215 E Lowell Street, Tucson, AZ 85721
  • Take the elevator to the 3rd floor, go to the east side of the building.