Gery AllenGery Allan is a molecular ecologist interested in understanding the genetic basis of ecologically important traits in cottonwood trees. His research focuses on plant-insect interactions with a view toward investigating how insects respond to genetic variation in foundation tree species. With a background in plant genetics and phylogenetics, Allan is also working toward merging phylogenetic approaches with insect community diversity in a relatively new field called “community phylogenetics.”

At Northern Arizona University, Allan is the Director of the Environmental Genetics & Genomics (EnGGen) Facility and an Associate Professor in the Department of Biological Sciences.

For more information, contact Allan at


Joe BaileyJoe Bailey is an Evolutionary Ecologist who has worked, nationally and internationally, for more than 10 years to understand how genetic variation in dominant species on the landscape drive ecological interactions that influence biodiversity and ecosystem function.

In 2009, Bailey was awarded the Australian Research Council’s “Future Fellowship,” a program built “to attract and retain the best and brightest midcareer researchers” globally to work in Australia. Bailey is Assistant Professor in the Department of Ecology and Evolutionary Biology at the University of Tennessee.  Currently, his Genes to Ecosystems Lab focuses on the interactions among plant genetic variation, global change, and environmental gradients as they effect biodiversity and ecosystem function.

For more information, contact Bailey at


Catherine GehringCatherine Gehring studies interactions among plants and their ubiquitous associated fungi, including the mycorrhizal fungi that aid plants in soil-resource uptake and can provide protection from herbivory and disease.  Her studies and those of her students have emphasized complex interactions among insect herbivores, plant genetics, and fungi in both pinyon pines and cottonwoods.  She has explored similar complex interactions in tropical systems.

Gehring is a Professor in the Department of Biological Sciences at Northern Arizona University (NAU) where she also serves as director of NAU’s Genes to Environment graduate training program.

For more information, contact Gehring at


Steve DiFazioStephen DiFazio is a plant molecular geneticist who was a major participant in the first genome sequencing project for a forest tree—the poplar—while he worked at Oak Ridge National Laboratory.

Currently, DiFazio is Associate Professor in Biology at West Virginia University (WVU) and Director of the WVU Genomics Core Facility. He is seeking to mine the genome sequences of poplar and associated organisms to discover genes that are important for adaptation and speciation and potentially useful for biofuels production.

For more information, contact DiFazio at


Steven HartStephen Hart is a terrestrial microbial and ecosystem ecologist who works at the interface between the biological and earth sciences. He began working with Tom Whitham and colleagues on the genetic foundations of terrestrial ecosystems soon after arriving at Northern Arizona University (NAU) in 1991. Hart’s contribution to this research has focused on how plant genes can influence the composition and structure of soil microbial communities that are responsible for important ecosystem processes such as nutrient cycling.

In 2008, Hart left NAU to become Professor of Ecology in the School of Natural Sciences and the Sierra Nevada Research Institute at the University of California, Merced—the first new American research university in the 21st century. Currently, he serves as Chair of the Environmental Systems Graduate Program, a Technical Editor for the Soil Science Society of America Journal, and Subject Matter Editor for the journals Ecosystems and Forests. In 2011, Hart was elected a Fellow of the Soil Science Society of America, the highest recognition given by the society, based on his professional achievements and meritorious service. Only 0.3 percent of the society’s active and emeritus members receive that honor.

For more information, contact Hart at


Rick LindrothRick Lindroth is an international authority in the disciplines of chemical ecology and global change biology. For 25 years he has explored how genetic and environmental factors shape the chemical composition of poplar species and the resulting consequences for species interactions and ecosystem function.

Lindroth is Professor and Associate Dean for Research at the University of Wisconsin-Madison, a Fellow of the American Association for the Advancement of Science, and a former Fulbright Fellow. In 2009, he received the Silverstein-Simeone Award in Chemical Ecology from the International Society of Chemical Ecology.

For more information, contact Lindroth at


Jane MarksJane Marks is a stream ecologist forging innovative research to understand how trees living along streams affect stream insects and fish.  Her research, highlighted in A Thousand Invisible Cords, shows how important it is to understand the type of trees to plant to support healthy rivers.

Marks, a Professor in the Department of Biological Sciences at Northern Arizona University, has been working on restoring rivers for the past 15 years.  One of her major successes has been to create projects that use large restoration actions as ecological experiments.  Through this work, she is providing valuable information to restoration managers about how best to restore rivers.  Marks’ research in Fossil Creek in central Arizona has been featured in the documentary A River Reborn.


Richard MichaletRichard Michalet is a plant community ecologist, primarily interested in biotic interactions, and in particular, in positive plant interactions in stressful environments, such as alpine communities, arid and desert ecosystems, sand dunes, salt marshes, and forest communities. His most well-known contributions concern the role of positive interactions among plants for community diversity and the role of plant strategies in facilitative responses. Recently, he expanded his research interest to include community genetics, focusing on the role of positive plant interactions for community evolution, in particular in cushion systems in various alpine environments, such as the San Francisco Peaks in Arizona, USA; Mount Lebanon, Lebanon; Sierra Nevada, Spain; and the Pyrenees, France.

Richard Michalet is Professor of Ecology, UMR EPOC, University of Bordeaux 1 in France, and head of the university’s PhD School Sciences & Environments.

For more information, contact Michalet at


Brad PottsBrad Potts is a eucalypt geneticist working on the island of Tasmania, Australia.  Eucalypts are a specious hemisphere plant group, which dominate many of Australia’s forests and woodlands and range in size from small shrubs to the tallest flowering plant on earth.  Potts studies the evolutionary processes that have shaped the patterns of variation and adaptation seen in eucalypts today.  He started working with Whitham in 1989, studying the effects of eucalypt hybridization on the dependent insect and fungal communities, and this collaboration has been ongoing. Potts has established a large base of pedigreed field trials of eucalypts for studying the extent to which characteristics of the tree are under genetic control and how this genetic variation extends to affect associated organisms, including Australia’s unique marsupials.

Potts is Professor of Forest Genetics in the School of Plant Science at the University of Tasmania. He was honored with The Royal Society of New South Wales’ 2008 Clarke Medal for distinguished work in a natural science done in Australia and its Territories.

For more information, contact Potts at


Jen SchweitzerJen Schweitzer is an ecosystem ecologist whose research focuses on the role of plant-soil linkages and feedbacks to soil development and nutrient cycling and the ecological and evolutionary importance of these linkages to both soils and plants. Her research has utilized multiple species, including Populus spp. in the western part of the United States (U.S.), Eucalyptus spp. in Australia, Ailanthus spp. and Solidago spp. in the southeastern U.S., and Meterosideros spp. in Hawai’i.  She investigates genetic linkages among plants and soils in a range of contexts, such as forest management, invasion biology, biodiversity and ecosystem function, and global change—the results of which have both applied and theoretical importance to the conservation and sustainability of terrestrial ecosystems.

Schweitzer is an Assistant Professor in the Department of Ecology and Evolutionary Biology at the University of Tennessee.

For more information, contact Schweitzer at


Steve ShusterSteve Shuster is an invertebrate zoologist who realized the power of theoretical evolutionary genetics as a postdoctoral fellow in Michael J. Wade’s laboratory at the University of Chicago. Shuster and Wade’s book, Mating Systems and Strategies (2003, Princeton University Press), uses this framework to predict the details of plant and animal breeding systems, providing the first comprehensive treatise on this subject since the Modern Synthesis. By applying quantitative genetic methods to traditional ecological data, Shuster provided the theoretical foundation for A Thousand Invisible Cords’ conclusion that ecosystem organization is genetically based.

Shuster is Professor of Invertebrate Zoology in the Department of Biological Sciences at Northern Arizona University, and has served as Distinguished Lecturer and Visiting Scientist at universities in Sweden, Norway, Finland, Brazil, Mexico, and the USA.

For more information, contact Shuster at


Tom WhithamTom Whitham is a pioneer in the science of community and ecosystem genetics. Thirty years ago he began the research that is the foundation of A Thousand Invisible Cords when he planted a common garden of cottonwood trees to see if genetics or other conditions affected the trees’ resistance to aphids. Soon other researchers joined him. That collaboration led to major discoveries about the genetic underpinnings of community structure and ecosystem processes.

Whitham is Regents’ Professor in the Department of Biological Sciences at Northern Arizona University, a Fellow of the American Association for the Advancement of Science, and Executive Director of the Merriam-Powell Center for Environmental Research. In 2011, Whitham received the prestigious Eminent Ecologist Award by the Ecological Society of America—the group’s highest honor—for his outstanding body of work.

For more information, contact Whitham at


Dan Boone, the film’s producer and director, is a film producer and scientific imaging specialist at Northern Arizona University (NAU). As director of NAU’s IDEA Lab, Boone has worked with scientists for more than 20 years to communicate important research concepts to a popular audience. He has won numerous awards for his video productions and still photography.

Ryan Belnap, the film’s first assistant director and line producer, is senior photographer of NAU’s IDEA Lab. “Belnap’s great eye for design and his skills with the camera and lighting have made this movie beautiful as well as informative,” notes Boone.


  • Northern Arizona University
  • National Science Foundation
  • University of Tasmania
  • Bureau of Reclamation
  • Merriam Powell Cemter for Environmental Research